U.S. patent application number 09/870682 was filed with the patent office on 2001-10-11 for digital key telephone system and extension terminal device thereof.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Kawauchi, Yoshihiro, Kimura, Setsuo, Komuro, Isaku, Mano, Hiroshi, Masaki, Nobuhiro, Nagano, Yoshihito, Suwa, Terunori, Tanaka, Toshiaki, Tsurusaki, Masayuki, Watanabe, Takashi.
Application Number | 20010028708 09/870682 |
Document ID | / |
Family ID | 26363308 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010028708 |
Kind Code |
A1 |
Tanaka, Toshiaki ; et
al. |
October 11, 2001 |
Digital key telephone system and extension terminal device
thereof
Abstract
According to this invention, a digital key telephone system
connected to an analog public network NW having a function of
transmitting a ringing signal including identification information
of a calling line through a subscriber line (CO line),
accommodating a plurality of extension lines each connected to a
digital key telephone (DKT) 2 or a standard telephone (STT) 4 as an
extension terminal, and having a function of switching and
connecting the subscriber line to the plurality of extension lines
or the extension lines to each other includes a called party
storage means storing, in advance, information representing the
correlation between the calling line and the extension terminals 2
and 4 as a called terminal. When a ringing signal arrives from the
analog communication network NW, calling line identification
information (caller ID) contained in the ringing signal is detected
by a calling line identification information interface unit (RCIU)
12. A control unit (RCTU) 16 determines the called extension
terminal on the basis of the detected caller ID and the information
stored in the storage means, so the extension terminal receives the
call from the digital key telephone interface unit (RDKU) 13 or a
standard telephone interface unit (RSTU) 15.
Inventors: |
Tanaka, Toshiaki; (Tokyo,
JP) ; Mano, Hiroshi; (Tokyo, JP) ; Kimura,
Setsuo; (Tokyo, JP) ; Nagano, Yoshihito;
(Yokohama-shi, JP) ; Tsurusaki, Masayuki; (Tokyo,
JP) ; Watanabe, Takashi; (Tokyo, JP) ; Suwa,
Terunori; (Tokyo, JP) ; Komuro, Isaku; (Tokyo,
JP) ; Kawauchi, Yoshihiro; (Tokyo, JP) ;
Masaki, Nobuhiro; (Tokyo, JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT &
DUNNER LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Assignee: |
Kabushiki Kaisha Toshiba
|
Family ID: |
26363308 |
Appl. No.: |
09/870682 |
Filed: |
June 1, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09870682 |
Jun 1, 2001 |
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09125154 |
Aug 13, 1998 |
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6263061 |
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09125154 |
Aug 13, 1998 |
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PCT/JP97/00369 |
Feb 13, 1997 |
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Current U.S.
Class: |
379/156 |
Current CPC
Class: |
H04Q 2213/13203
20130101; H04Q 2213/13362 20130101; H04M 2242/22 20130101; H04Q
2213/13036 20130101; H04Q 2213/13102 20130101; H04Q 2213/13251
20130101; H04M 3/42323 20130101; H04Q 2213/13213 20130101; H04Q
2213/13093 20130101; H04M 3/42127 20130101; H04Q 2213/13299
20130101; H04Q 2213/13334 20130101; H04Q 2213/13174 20130101; H04Q
2213/13216 20130101; H04Q 2213/13322 20130101; H04Q 2201/806
20130101; H04Q 2213/13405 20130101; H04Q 2201/10 20130101; H04M
9/00 20130101; H04Q 2213/13034 20130101; H04Q 2213/13091 20130101;
H04Q 2213/1316 20130101; H04Q 2213/13209 20130101; H04M 3/42
20130101; H04Q 2213/1318 20130101; H04Q 2213/1334 20130101; H04M
3/428 20130101; H04M 3/4283 20130101; H04M 9/002 20130101; H04M
2201/38 20130101; H04Q 2213/1332 20130101; H04Q 2213/13103
20130101; H04M 3/58 20130101; H04Q 2213/13076 20130101; H04Q
2213/13196 20130101; H04M 3/22 20130101; H04Q 2213/13392 20130101;
H04M 3/533 20130101; H04Q 2213/13201 20130101; H04Q 3/625 20130101;
H04Q 2213/13096 20130101; H04Q 2213/13106 20130101; H04Q 2213/13173
20130101; H04Q 2213/13003 20130101; H04Q 2213/13302 20130101; H04Q
2213/13292 20130101; H04M 3/42059 20130101; H04M 1/57 20130101;
H04Q 1/10 20130101; H04Q 3/545 20130101; H04Q 2213/13097 20130101;
H04Q 3/58 20130101; H04Q 2213/13152 20130101; H04Q 2213/13162
20130101; H04Q 2213/13199 20130101; H04Q 2213/13242 20130101; H04Q
2213/1326 20130101; H04M 3/26 20130101; H04M 3/42314 20130101; H04M
2207/08 20130101; H04Q 2213/13175 20130101; H04M 3/42195 20130101;
H04Q 1/028 20130101; H04Q 2213/1308 20130101; H04Q 2213/1322
20130101; H04Q 11/0407 20130101; H04Q 2213/13204 20130101; H04Q
2213/13305 20130101; H04Q 2213/1315 20130101; H04Q 2213/13282
20130101; H04Q 2213/13377 20130101 |
Class at
Publication: |
379/156 |
International
Class: |
H04M 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 13, 1996 |
JP |
8-025658 |
Claims
1. a digital key telephone system connected, through an office
line, to an analog communication network having a function of
transmitting a ringing signal including calling line identification
information, accommodating a plurality of extension lines connected
to extension terminals, and having a function of switching and
connecting the office line to the plurality of extension lines or
the extension lines to each other, characterized by comprising:
called party storage means storing information representing a
correlation between a calling line and a called extension terminal;
identification information detection means for detecting the
calling line identification information included in the ringing
signal arriving from the analog communication network; and call
reception control means for determining the called extension
terminal on the basis of the calling line identification
information detected by said identification information detection
means and the information stored in said storage means and
performing call reception processing for the extension
terminal.
2. A digital key telephone system connected, through an office
line, to an analog communication network having a function of
transmitting a ringing signal including calling line identification
information, accommodating a plurality of extension lines connected
to extension terminals, and having a function of switching and
connecting the office line to the plurality of extension lines or
the extension lines to each other, characterized by comprising:
identification information detection means for detecting the
calling line identification information included in the ringing
signal arriving from the analog communication network; calling line
identification information storage means for storing the calling
line identification information detected by said identification
information detection means in correspondence with a called
extension terminal when call reception processing is performed for
the called extension terminal in response to arrival of the ringing
signal, and the extension terminal does not answer the call; and
call back control means for, when an operation of requesting call
back is performed in the extension terminal which does not answer
the call, performing call back processing for the calling line on
the basis of the calling line identification information stored in
said calling line identification information storage means.
3. A digital key telephone system according to claim (2),
characterized in that said calling line identification information
storage means monitors restoration of the office line which has
received a call during call reception processing and stores the
calling line identification information upon detecting the
restoration.
4. A digital key telephone system connected, through an office
line, to an analog communication network having a function of
transmitting a ringing signal including calling line identification
information, accommodating a plurality of extension lines connected
to extension terminals, and having a function of switching and
connecting the office line to the plurality of extension lines or
the extension lines to each other, characterized by comprising:
calling line identification information extraction means for, when
the calling line identification information has calling line
identification data and redundant data added before and after the
identification data, extracting the calling line identification
data and the redundant data from the received ringing signal; and
fault determination means for performing fault determination
processing separately for each of the office line and said digital
key telephone system on the basis of the calling line
identification data and the redundant data extracted by said
calling line identification information extraction means.
5. A digital key telephone system according to claim (4),
characterized in that said digital key telephone system comprises
mode designation input means for designating and inputting one of a
normal call reception processing mode and a fault determination
mode, and when the fault determination mode is designated by said
mode designation input means, said calling line identification
information extraction means extracts the calling line
identification data and the redundant data from the received
ringing signal and uses the data for fault determination processing
by said fault determination means, and when the normal call
reception processing mode is designated, said calling line
identification information extraction means extracts only the
calling line identification data from the received ringing signal
and uses the calling line identification data for normal call
reception by call reception control means.
6. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other
and an external communication interface connected to a plurality of
external computer devices, characterized by comprising: function
setting means for receiving function setting information sent from
one of the plurality of external computer devices through a
corresponding external communication interface and setting a
function of said digital key telephone system in accordance with
the received function setting information; and function setting
regulation means for, while the function setting information is
arriving from one of the plurality of external computer devices,
regulating a function setting operation in the remaining external
computer devices.
7. A digital key telephone system according to claim (6),
characterized in that while the function setting operation is being
performed in one of the plurality of external computer devices,
said function setting regulation means transmits message
information representing that function setting is disabled to at
least the remaining external computer devices which are going to
perform the function setting operation, and displays the message
information.
8. A digital key telephone system according to claim (6),
characterized in that when contents of function setting by the
plurality of external computer devices are in competition, said
function setting means preferentially operates a function set by
one of said external computer devices, in accordance with a
predetermined rule.
9. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other
and an external communication interface connected to a plurality of
external computer devices, characterized in that the external
communication interface comprises serial communication interface
means for serially transmitting a digital signal to said external
computer device, modem communication interface means for
modem-transmitting a digital signal to said external computer
device, and interface switching means for switching between said
serial communication interface means and said modem communication
interface means, and said digital key telephone system comprises
switching control means for detecting a communication request input
in signal transmission to said external computer device, and
controlling said interface switching means, in accordance with a
communication request detection result, to enable signal
transmission to said external computer device as the other party of
communication.
10. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other
and an external communication interface connected to a plurality of
external computer devices, characterized in that said digital key
telephone comprises evaluation test control means for performing an
evaluation test of said digital key telephone system in cooperation
with said external computer device, and the external communication
interface comprises a first signal path for transmitting a signal
sent from said external computer device, transferring the signal to
said evaluation test control means, and transferring the signal
looped back by said evaluation test control means to said external
computer device, a second signal path for looping back the signal
sent from said external computer device to said external computer
device without transferring the signal to said evaluation test
control means, and means for selectively switching the first and
second signal paths under the control of said evaluation test
control means.
11. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other
and an external communication interface having a plurality of
serial communication ports connected to external computer devices,
characterized in that the external communication interface
comprises a table memory which stores information representing a
relationship between the number of serial communication ports
connected to external computer devices and transmission rates which
can be set for each serial communication port, and transmission
rate setting control means for, every time an external computer
device is connected to one of the plurality of serial communication
ports, assigning a transmission rate on the basis of the
information stored in said table memory such that a sum of
transmission rates of the plurality of serial communication ports
is not more than a predetermined total transmission capability.
12. A digital key telephone system according to claim (11),
characterized in that the external communication interface
comprises means, having a specific serial communication port for
which a predetermined transmission attribute is permanently set in
advance, for setting a transmission attribute for the remaining
serial communication ports on the basis of setting information sent
from an external computer device connected to the specific serial
communication port.
13. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other,
characterized by comprising: detection means for detecting at least
a power factor of each of the extension terminals connected to the
extension lines; determination means for determining whether a sum
value of the power factors of the extension terminals, which are
detected by said detection means, falls within a prescribed value;
and notification means for notifying a determination result to a
user.
14. A digital key telephone system according to claim (13),
characterized in that when the sum value of the power factors
exceeds the prescribed value, said notification means sends a
warning message to a predetermined extension terminal or an
arbitrary extension terminal to display the warning message.
15. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other,
characterized in that said digital key telephone system comprises a
basic cabinet accommodating a control unit for at least the
switching/connection, and a plurality of extension cabinets
accommodating a plurality of interface units each having an
interface function to at least the office line and the extension
lines, stacked on said basic cabinet, and connected to each other
through a connection cable, and said extension cabinet comprises
stacking position recognition means for recognizing a stacking
position of a self frame on the basis of a predetermined signal
sent from said basic cabinet, and channel conversion control means
for performing conversion between an interframe transmission
channel for performing signal transmission to said basic cabinet
and an intraframe transmission channel for performing signal
transmission to each interface unit in the self frame in accordance
with the stacking position recognized by said stacking position
recognition means.
16. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other
by a time switch and, simultaneously with switching/connection,
sending a predetermined tone signal generated by a tone generator
to a corresponding office line or extension line through the time
switch, characterized in that the time switch comprises digital
level conversion means for converting an input signal level of each
time slot into a different signal level and outputting the signal,
and level control means for, in sending the tone signal to the
office line or the plurality of extension lines, controlling a gain
of said digital level conversion means in accordance with a state
of the office line or extension line to which the signal is to be
sent.
17. A digital key telephone system having a main unit connected to
a communication network through an office line and accommodating a
plurality of extension lines connected to extension terminals, and
having a function of switching and connecting the office line to
the plurality of extension lines or the extension lines to each
other, characterized by comprising: camp-on control means for, when
a new call arrives at an extension line which is communicating,
holding at least the new call; and camp-on tone generation means
for generating a camp-on tone in the called extension terminal when
the new call is being held by said camp-on control means while
changing the type of camp-on tone depending on whether the new call
is arriving at the office line or the extension line.
18. A digital key telephone system according to claim (17),
characterized in that when the extension terminals include a
digital telephone and a standard telephone, said camp-on tone
generation means comprises determination means for determining
whether the called extension terminal is the digital telephone or
the standard telephone, first means for, when said determination
means determines that the called extension terminal is the digital
telephone, sending a command for instructing generation of the
camp-on tone and the type thereof from said main unit to the called
extension terminal to cause the extension terminal to generate the
camp-on tone in accordance with the command, and second means for,
when said determination means determines that the called extension
terminal is the standard telephone, generating the camp-on tone in
said main unit, inserting the camp-on tone into a reception channel
of the called extension terminal and sending the camp-on tone to
the called extension terminal to cause the called extension
terminal to output the camp-on tone.
19. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, and having a
function of switching and connecting the office line to the
plurality of extension lines or the extension lines to each other,
characterized by comprising: directory storage means storing
directory numbers assigned to the plurality of extension terminals
in correspondence with the extension terminals; and directory
retrieval display means for, when a directory number retrieval
operation is performed in the extension terminal in a predetermined
procedure, reading out a directory number assigned to the extension
terminal from said directory storage means and transmitting the
directory number to the extension terminal which has performed the
directory number retrieval operation to display the directory
number.
20. A digital key telephone system comprising a main unit connected
to a communication network through an office line, accommodating a
plurality of extension lines, and having at least a function of
switching and connecting the office line to the plurality of
extension lines or the extension lines to each other, and a
plurality of extension terminals connected to the plurality of
extension lines of said main unit, characterized in that at least
one of the plurality of extension terminals comprises means for
sending a request for knowing contents of an incoming call
addressed to the extension terminal, and said main unit comprises
call reception information notification control means for, when the
request for knowing the contents of the incoming call is sent from
the extension terminal where the incoming call waiting for call
reception processing is present, supplying call reception
information representing the contents of the incoming call waiting
for call reception processing to the extension terminal of the
request source in accordance with the request.
21. A digital key telephone system according to claim (20),
characterized in that the extension terminal comprises a digital
key telephone connected to an extension line and a computer device
connected to said digital key telephone through an interface, the
request for knowing the contents of the incoming call is sent from
said computer device to said main unit, and the call reception
information supplied from said main unit is displayed on said
computer device.
22. A digital key telephone system comprising claim (20) or (21),
characterized in that the extension terminal sends the request for
knowing the contents of the incoming call addressed to the
extension terminal at one of a timing of a request operation by a
user and a predetermined sending timing.
23. A digital key telephone system according to claim (20) or (21),
characterized in that when a plurality of incoming calls waiting
for call reception processing are present in an extension terminal,
and every time a request for knowing contents of an incoming call
is sent from the extension terminal, said call reception
information notification control means sequentially selects the
plurality of incoming calls and supplying call reception
information representing the contents to the extension terminal of
the request source.
24. A digital key telephone system connected to a communication
network through an office line, accommodating a plurality of
extension lines connected to extension terminals, having a function
of switching and connecting the office line to the plurality of
extension lines or the extension lines to each other, and
comprising call park control means for, when a call park request is
input in an extension terminal which is communicating, holding a
call to the extension terminal in correspondence with an orbit
number, and in this state, when another extension terminal accesses
the orbit number, connecting the extension terminal to the held
call, characterized in that said call park control means holds the
orbit number until the call is ended in holding the call subjected
to call park in correspondence with the orbit number, and when a
repark request for the call is generated while the call is
continuously received, the call is held in correspondence with the
orbit number at which the call is being held.
25. A digital key telephone system comprising a main unit connected
to a communication network through an office line, accommodating a
plurality of extension lines, and having at least a function of
switching and connecting the office line to the plurality of
extension lines or the extension lines to each other, a plurality
of extension terminals connected to the plurality of extension
lines of said main unit, and a computer connection interface added
to at least one of the extension terminals, characterized in that
said digital key telephone system comprises means for, when an
operation mode change request arrives at the computer connection
interface from a computer connected to the computer connection
interface, transferring the change request to said main unit, said
main unit comprises means for, when the mode change request is
transferred from the computer connection interface, determining
whether the mode change request is appropriate, and supplying a
determination result to the computer connection interface which has
transferred the mode change request, and the computer connection
interface comprises means for performing mode change processing in
response to the mode change request from the computer on the basis
of the determination result supplied by said main unit after
transfer of the mode change request.
26. A digital key telephone system comprising a main unit connected
to a communication network through an office line, accommodating a
plurality of extension lines, and having at least a function of
switching and connecting the office line to the plurality of
extension lines or the extension lines to each other, and a
plurality of extension terminals having a plurality of line
selection keys each corresponding to the office line or the
extension line and connected to the plurality of extension lines,
characterized by comprising: line holding means for holding the
office line or the extension line corresponding to one of the
plurality of line selection key; first display means for, when a
request for displaying information associated with the office line
or the extension line held by said line holding means is input in
an extension terminal, selectively displaying the information
associated with the held office line or extension line on the
extension terminal in accordance with the input; and second display
means for, synchronized with a display operation by said first
display means, displaying information representing the line
selection key corresponding to the held office line or extension
line.
27. A digital key telephone system according to claim (26),
characterized in that when indication lamps are arranged in
correspondence with the line selection keys, said second display
means turns on an indication lamp corresponding to the office line
or the extension line for which the holding information is being
displayed by said first display means.
28. A digital key telephone system according to claim (26),
characterized in that said first and second display means
simultaneously display the information associated with the held
office line or extension line and the information representing the
line selection key corresponding to the office line or the
extension line on a display device of the extension terminal.
29. An extension terminal device connected to an extension line of
a main unit connected to a communication network through an office
line, accommodating a plurality of extension lines, and having at
least a function of switching and connecting the office line to the
extension lines or the extension lines to each other and line
holding means for holding the office line or the extension lines,
characterized by comprising: a plurality of line selection keys
each corresponding to the office line or the extension line; first
display means for, when a request for displaying information
associated with the office line or the extension line held by said
line holding means is input in an extension terminal, selectively
displaying the information associated with the held office line or
extension line on the extension terminal in accordance with the
input; and second display means for, synchronized with a display
operation by said first display means, displaying information
representing the line selection key corresponding to the held
office line or extension line.
30. An extension terminal device according to claim (29),
characterized in that said first display means selectively displays
a number representing the held extension line or office line,
calling line identification information, a directory number, and
information representing a user name.
Description
TECHNICAL FIELD
[0001] The present invention relates to a digital key telephone
system provided in a company or an office.
BACKGROUND ART
[0002] A digital key telephone system comprises a main unit
connected to a public network or a private branch exchange and a
plurality of digital key telephones connected to the extension
lines of the main unit. The digital key telephone has a plurality
of push button type keys. When these keys are depressed, calling
the public network or the private branch exchange, answering a
call, and speech communication between digital key telephones are
allowed. The main unit processes not only a control signal but also
a speech communication signal as a digital signal and executes
calling processing/call reception processing of each digital key
telephone by a stored program control scheme and switching
processing by a time switch of the digital speech communication
signal.
[0003] As one of analog communication networks provided in U.S.A.
recently, there is a communication network for providing a service
called, e.g., "CLASS (Custom Local Area Signaling Service)". The
communication network for providing the CLASS service can superpose
calling line identification information on a call signal and
transmit it to the called subscriber.
[0004] When the digital key telephone system is connected to such a
communication network, the main unit of the called digital key
telephone system detects the first bell signal and then a modem
signal. When calling line identification information is detected
from the modem signal, the calling line identification information
is transferred from the main unit to the called key telephone and
displayed on the liquid crystal display device (LCD) of the key
telephone. The user of the key telephone can recognize the calling
line before off-hook by checking the calling line identification
information displayed on the liquid crystal display device.
[0005] Conventionally, however, as the main function of the digital
key telephone system using the calling line information
notification service in the analog communication network such as
the CLASS service, only the above-described calling line
identification information display function is realized. Therefore,
a demand has arisen for realization of a new and effective
functional service using the CLASS service.
[0006] Another demand has arisen for expansion or realization of
various support functions associated with wiring installation, a
function of allowing a variety of call reception processing by
adding a plurality of extension numbers to the digital key
telephones, and a function of allowing a variety of communication
processing operations using a personal computer combined with the
digital key telephones.
DISCLOSURE OF INVENTION
[0007] It is an object of the present invention to provide a
digital key telephone system capable of expanding or realizing
various functions, e.g., realizing a more effective function using
a calling line information notification service in an analog
communication network.
[0008] In order to achieve the above object, according to the
present invention, there is provided a digital key telephone system
connected, through an office line, to an analog communication
network having a function of transmitting a ringing signal
including calling line identification information, accommodating a
plurality of extension lines connected to extension terminals, and
having a function of switching and connecting the office line to
the plurality of extension lines or the extension lines to each
other, comprising called party storage means storing information
representing a correlation between a calling line and a called
extension terminal in advance. By detecting the calling line
identification information included in the ringing signal arriving
from the analog communication network, the called extension
terminal is determined on the basis of the detected calling line
identification information and the information stored in the
storage means, and call reception processing for the extension
terminal is performed.
[0009] When called parties are registered in advance in
correspondence with calling parties, an optimum extension terminal
user can answer a call from a calling line. For example, a terminal
for receiving and answering a call can be can be appropriately
selected such that a person in charge directly answers a call from
an important client, and a secretary answers calls from other
clients.
[0010] In the present invention, when call reception processing is
performed for the called extension terminal in response to arrival
of the ringing signal, and the extension terminal does not answer
the call, the calling line identification information detected from
the ringing signal is stored in correspondence with the called
extension terminal. When an operation of requesting call back is
performed in the extension terminal which does not answer the call,
call back processing is performed for the calling line on the basis
of the stored calling line identification information. The calling
line identification information is stored upon detecting
restoration of the called office line during call reception
processing.
[0011] If a call is received in the absence of the extension
terminal user, the user can perform call back without the dialing
operation only by performing the call back request operation. For
this reason, the user operation associated with the call back
operation can be simplified.
[0012] In the present invention, fault determination means using
the calling line identification information is arranged. A
detection result obtained when the calling line identification
information included in the ringing signal is detected by the
calling line identification information detection means is compared
with that obtained when the calling line identification information
is passed through the calling line identification information
detection means together with the redundant data and detected by
the fault determination means. With this operation, when a
reception fault of the ringing signal is generated, determination
processing is separately performed for each of the office line and
the digital key telephone system.
[0013] With this arrangement, the fault occurrence position can be
determined using the calling line identification information
arriving from the analog communication network. As a result,
separate fault determination can be relatively easily and properly
performed, so a measure against the fault can be appropriately and
quickly taken.
[0014] According to the present invention, there is also provided a
digital key telephone system comprising an external communication
interface with a plurality of serial communication ports for
performing serial communication with external computer devices, and
having a function of receiving function setting information sent
from the external computer device through the external
communication interface and setting a function of the digital key
telephone system in accordance with the received function setting
information, comprising function setting regulation means. While
the function setting information is being received from an
arbitrary one of the plurality of external computer devices,
message information representing that function setting is disabled
is transmitted to another external computer device, which is going
to perform the function setting operation, and displayed, thereby
regulating the function setting operation in another external
computer device.
[0015] With this arrangement, the plurality of external computer
devices are prevented from simultaneously performing function
setting, so congestion of function setting processing from the
plurality of external computer devices can be prevented.
[0016] When functions with different contents are set by the
plurality of external computer devices, a function set by one of
the external computer devices is preferentially operated in
accordance with a predetermined rule. With this arrangement, even
when a plurality of functions with inconsistent functions are set,
the system can be prevented from erroneously operating.
[0017] In the present invention, the external communication
interface comprises serial communication interface means for
serially transmitting a digital signal to the external computer
device, modem communication interface means for performing modem
communication of a digital signal to the external computer device,
and a switching circuit for switching between the serial
communication interface means and the modem communication interface
means. A communication request input before signal transmission to
the external computer device is detected, and the switching circuit
is controlled in accordance with the detection result to allow
signal transmission to the external computer device as the other
party of communication.
[0018] With this arrangement, data can be transmitted/received even
to/from an external computer device connected to a serial
communication interface such as an RS232C or an external computer
device connected through a communication line such as an office
line or extension line.
[0019] In the present invention, evaluation test control means for
performing an evaluation test of the digital key telephone system
in cooperation with the external computer device is arranged. In
addition, the external communication interface comprises a first
signal path for transmitting a signal sent from the external
computer device, transferring the signal to the evaluation test
control means, and transferring the signal looped back by the
evaluation test control means to the external computer device, and
a second signal path for looping back the signal sent from the
external computer device to the external computer device without
transferring the signal to the evaluation test control means. The
first and second signal paths are switched by the text control
means.
[0020] With this arrangement, text data returned through the first
signal path and that returned through the second signal path are
compared in the external computer device, thereby confirming
whether the control circuit in the digital key telephone system
properly operates.
[0021] According to the present invention, there is also provided a
digital key telephone system having an external communication
interface with a plurality of serial communication ports connected
to external computer devices, wherein the external communication
interface comprises a table memory which stores, in advance,
information representing a relationship between the number of
serial communication ports connected to external computer devices
and transmission rates which can be set for each serial
communication port. Every time an external computer device is
connected to one of the plurality of serial communication ports, a
transmission rate is assigned to the serial communication port on
the basis of the information stored in the table memory such that a
sum of transmission rates of the plurality of serial communication
ports is not more than a predetermined total transmission
capability.
[0022] In accordance with the number of external computer devices
connected to the serial communication ports, the maximum
transmission rate can always be assigned to each external computer
device within the range under the condition at that time.
Therefore, data transmission can always be performed by using the
transmission capacity of the external communication interface at
maximum, so a high transmission capacity utilization efficiency can
be maintained.
[0023] In the present invention, in mounting units or connecting
extension terminals, the power factor of each of the mounted units
and connected extension terminals is detected, it is determined
whether the sum value of the detected power factors of the units
and extension terminals falls within a prescribed value, and the
determination result is notified to a user. As the determination
result notification means, when the sum value of the power factors
of, e.g., extension terminals exceeds the prescribed value, a
warning is issued to the extension terminal to be connected.
[0024] With this arrangement, even when the installer or the like
is to erroneously connect a number of extension terminals beyond
the prescribed power factor value, the installer is warned of it,
so connection of a number of extension terminals beyond the
prescribed power factor value can be prevented.
[0025] According to the present invention, there is also provided a
digital key telephone system comprising a basic cabinet
accommodating a control unit for switching/connection, and a
plurality of extension cabinets accommodating a plurality of
interface units each having an interface function to an office line
and extension lines, the extension cabinets being stacked on the
basic cabinet and connected to each other through a connection
cable, wherein each extension cabinet comprises stacking position
recognition means for recognizing a stacking position of a self
frame on the basis of a predetermined signal sent from the basic
cabinet. In accordance with the stacking position recognized by the
stacking position recognition means, channel conversion between an
interframe transmission channel for performing signal transmission
to the basic cabinet and an intraframe transmission channel for
performing signal transmission to each interface unit in the self
frame is performed.
[0026] With this arrangement, transmission channel conversion
processing is performed in accordance with the stacking position of
each extension cabinet. That is, each extension cabinet can
autonomously switch the channel at any stacking position. Since the
extension cabinets can have a common arrangement, manufacturing of
extension cabinets can be simplified, and the cost can be reduced
by the mass production effect, as compared to the manufacture of a
dedicated extension cabinet at each stacking position.
[0027] In the present invention, digital level conversion means for
converting an input signal level of each time slot into a different
signal level and outputting the signal to a time switch for
switching and connecting the office line, the extension lines, and
a tone generator, and level control means are arranged. In sending
a tone signal from the tone generator to the office line or the
plurality of extension lines, the gain of the digital level
conversion means is changed in accordance with the state of the
office line or extension line to which the signal is to be
sent.
[0028] As a result, even when the tone signal is to be sent to a
plurality of parties, the tone signal generated by one tone signal
generator can be changed in level and sent in accordance with the
destination. Since a plurality of tone signal generators for
generating tone signals of different levels need not be arranged,
the cost of the system can be reduced, and the reliability can be
improved.
[0029] In the present invention, when the system has a camp-on
function of, if a new call arrives at an extension line which is
communicating, sending a camp-on tone from the main unit to the
extension line which is communicating to notify the call reception,
the camp-on tone is changed depending on whether the line at which
the call arrives is the office line or the extension line.
[0030] When another call addressed to the extension terminal during
communication is received, the user of the called extension
terminal can identify the calling line, i.e., the office line or
extension line, from the difference in camp-on tone, so the user
can appropriately answer the call in accordance with the calling
line.
[0031] As means for outputting the camp-on tone from the terminal,
first means for a digital key telephone and second means for a
standard telephone are selectively used. When the called terminal
is a digital key telephone, the main unit sends a command for
instructing generation of a camp-on tone and the type of the
camp-on tone because the digital key telephone has a sound source
for generating the tone. Upon receiving the command, the digital
key telephone generates a camp-on tone of the designated type from
the sound source and outputs the camp-on tone. To the contrary,
when the called terminal is a standard telephone, the main unit
generates the camp-on tone by itself because the standard telephone
has no tone source. The camp-on tone is mixed or inserted into the
reception signal and sent to the standard telephone.
[0032] With this arrangement, the camp-on tone can be generated
independently of the terminal, i.e., the digital key telephone or
the standard telephone.
[0033] In the present invention, when a directory number is
assigned to each extension terminal, and a directory number
retrieval operation is performed in the extension terminal in a
predetermined procedure, the directory number assigned to the
extension terminal is read out from directory storage means and
transmitted to the extension terminal which has performed the
directory number retrieval operation to display the directory
number.
[0034] With this arrangement, even when the user does not know or
forgets the directory number of the self extension terminal, the
directory number can be easily confirmed, as needed.
[0035] According to the present invention, there is also provided a
digital key telephone system comprising a main unit connected to a
communication network through an office line, accommodating a
plurality of extension lines, and having at least a function of
switching and connecting the office line to the plurality of
extension lines or the extension lines to each other, and a
plurality of extension terminals connected to the plurality of
extension lines of the main unit, wherein when a request for
knowing the contents of an incoming call is sent from one of the
plurality of extension terminals, where the incoming call waiting
for call reception processing is present, the main unit supplies
call reception information representing the contents of the
incoming call waiting for call reception processing to the
extension terminal of the request source in accordance with the
request.
[0036] With this arrangement, when a plurality of incoming calls
are simultaneously addressed to the self extension terminal, the
user can confirm the contents of these incoming calls and answer
the calls in the descending order of degrees of importance. When a
new incoming call is received during speech communication, the
contents of the incoming call are confirmed while continuing speech
communication. If the user determines that the new call is more
important, the call during speech communication is held or ended.
The user can immediately answer the important incoming call.
[0037] As a specific arrangement for realizing the call reception
information notification function, a request for knowing the
contents of the incoming call is sent from the digital key
telephone, and the call reception information sent from the main
unit is displayed on the digital key telephone. Alternatively, a
computer device is connected to the digital key telephone through
an interface. A request for knowing the contents of the incoming
call is sent from the computer device, and the call reception
information sent from the main unit is displayed on the computer
device.
[0038] As means for sending the request for knowing the contents of
the incoming call addressed to the self terminal, the request is
transmitted every time a request operation is performed by a user,
or the request is automatically transmitted at a predetermined
timing.
[0039] When a plurality of incoming calls are addressed to one
extension terminal, and every time a request for knowing contents
of an incoming call is sent from the extension terminal, call
reception information of one of the plurality of incoming calls is
sequentially selected and supplied. Alternatively, pieces of
information of all of the plurality of incoming calls may be
supplied in response to one request.
[0040] According to the present invention, there is also provided a
digital key telephone system comprising call park control means
for, when a call park request is input in an extension terminal
which is communicating, holding a call to the extension terminal in
correspondence with an orbit number, and in this state, when
another extension terminal accesses the orbit number, connecting
the extension terminal to the held call, wherein the call park
control means holds the orbit number until the call is ended in
holding the call subjected to call park in correspondence with the
orbit number, and when a repark request for the call is generated
while the call is continuously received, the call is held in
correspondence with the orbit number at which the call is being
held.
[0041] With this arrangement, when a repark request is generated,
the call to be subjected to call park at this time is held in
correspondence with the same orbit number as that in the preceding
call park. For this reason, a call is prevented from being held in
correspondence with different orbit numbers.
[0042] According to the present invention, there is also provided a
digital key telephone system having a computer connection interface
in at least one of extension terminals wherein an operation mode
change request sent from a computer is transferred to a main unit
through the computer connection interface, the main unit determines
whether the transferred mode change request is appropriate and
supplies the determination result to the computer connection
interface which has transferred to the mode change request, and the
computer connection interface comprises performs mode change
processing in response to the mode change request from the computer
on the basis of the supplied determination result.
[0043] With this arrangement, when a mode change request is issued
from the computer, the main unit always determines whether the
request is appropriate. Only when it is determined that the request
is appropriate, the computer connection interface performs mode
change setting. Therefore, the computer connection interface can
prevented from being set in a mode which is not prepared in the
main unit.
[0044] For example, assume that the user sends a request for
changing the mode to a computer telephoni mode from the computer to
the computer connection interface to send a call using the
computer. If the main unit does not have the computer telephoni
mode, the main unit returns no mode change enable notification. For
this reason, the computer telephoni mode is not set for the
computer connection interface. Even for an appropriate mode change
request, when the operation state in the main unit cannot currently
cope with the mode change, the main unit returns no mode change
enable notification.
[0045] According to the present invention, there is also provided a
digital key telephone system having a plurality of line selection
keys, in an extension terminal, each of which corresponds to the
office line or extension line, wherein when the office line or the
extension line corresponding to one of the plurality of line
selection key is held, and in this state, a request for displaying
information associated with the held office line or extension line
is input in an extension terminal, the information associated with
the held office line or extension line is selectively displayed on
the extension terminal in accordance with the display request, and
synchronized with the display operation, information representing
the line selection key corresponding to the held office line or
extension line is displayed.
[0046] As the means for displaying the information representing the
line selection key, an indication lamp such as an LED provided in
correspondence with the line selection key is turned on, or the
number of the line selection key is displayed on a display device
such as an LCD in correspondence with the number of the held
line.
[0047] Display control of the information representing the held
line and the information representing the line selection key can be
performed by the main unit or the extension terminal device.
[0048] With this arrangement, the information associated with the
held office line or extension line and the information representing
the line selection key corresponding to the office line or
extension line are displayed in correspondence with each other. For
this reason, the user can always properly recognize the line
selection key corresponding to the held line.
[0049] This arrangement is especially effective when a plurality of
directory numbers are added to one extension terminal. When a
plurality of lines with different directory numbers are being held,
the user performs the display operation to, e.g., scroll the pieces
of information of the held lines. Unless the user memorizes the
correspondence between the pieces of displayed line information and
the line selection keys, the user cannot know it. However, in the
present invention, in synchronization with the scroll operation,
the information of a line selection key corresponding to the
displayed line is displayed, and the user can properly know the
correspondence between the displayed line information and the line
selection key.
BRIEF DESCRIPTION OF DRAWINGS
[0050] FIG. 1 is a view showing the outer appearance of a digital
key telephone system according to an embodiment of the present
invention;
[0051] FIG. 2 is a block diagram showing the arrangement of a main
unit in the system shown in FIG. 1;
[0052] FIG. 3 is a circuit diagram showing the arrangement of an
RCOU in the main unit shown in FIG. 2;
[0053] FIG. 4 is a circuit diagram showing the arrangement of an
RCIU in the main unit shown in FIG. 2;
[0054] FIG. 5 is a circuit diagram showing the arrangement of an
RDKU in the main unit shown in FIG. 2;
[0055] FIG. 6 is a circuit diagram showing the arrangement of an
RSTU in the main unit shown in FIG. 2;
[0056] FIG. 7 is a circuit diagram showing the arrangement of an
RSIU in the main unit shown in FIG. 2;
[0057] FIG. 8 is a circuit diagram showing the arrangement of an
RCTU in the main unit shown in FIG. 2;
[0058] FIG. 9 is a block diagram showing the arrangement of a time
switch section in the RCTU shown in FIG. 8;
[0059] FIG. 10 is a plan view showing the outer appearance of a
digital key telephone;
[0060] FIG. 11 is a block diagram showing the circuit arrangement
of the digital key telephone;
[0061] FIG. 12 is a block diagram showing the arrangement of an
interface circuit section in the digital key telephone having a
PCI-DI;
[0062] FIG. 13 is a timing chart showing a caller ID reception
operation;
[0063] FIG. 14 is a flow chart showing the procedure and contents
of call reception sound generation control using the caller ID;
[0064] FIG. 15 is a view showing a table memory storing the
correlation between calling line numbers and sound generation
telephone numbers;
[0065] FIG. 16 is a view showing an example of display of CLASS
information on the digital key telephone;
[0066] FIG. 17 is a view showing an example of display of CLASS
information in a repeater;
[0067] FIG. 18 is a flow chart showing the procedure and contents
of call back control;
[0068] FIG. 19 show views of the sequence of switching a mode of
transmitting the caller ID from the RCIU to the RCTU;
[0069] FIG. 20 is a flow chart showing the procedure and contents
of function setting determination processing upon powering on;
[0070] FIG. 21 is a flow chart showing the procedure and contents
of determination processing when function setting is performed
during the operation of the system;
[0071] FIG. 22 is a view for explaining a state wherein an RS232C
interface connection mode is set for the RSIU;
[0072] FIG. 23 is a view for explaining a state wherein a
connection mode using a modem interface is set for the RSIU;
[0073] FIG. 24 is a view for explaining a state wherein a
connection mode using a modem interface is set for the RSIU;
[0074] FIG. 25 is a table showing the correlation between the
number of ports in use and the data transmission rate in the
RSIU;
[0075] FIG. 26 is a table showing the correlation between the use
purpose of a serial communication port and the communication
scheme;
[0076] FIG. 27 is a view showing the connection structure between a
basic cabinet and extension cabinets;
[0077] FIG. 28 is a block diagram showing the arrangement of a
connection interface circuit between a basic cabinet 1a and
extension cabinets 1b;
[0078] FIG. 29 is a table showing the correlation between each
extension cabinet, a cabinet position recognition signal, and a
data channel switching signal;
[0079] FIG. 30 is a circuit diagram showing the circuit arrangement
of a cabinet position recognition circuit;
[0080] FIG. 31 is a table showing the correlation between
basic-cabinet-side data and extension-cabinet-side data in a
downward link switching circuit of each extension cabinet;
[0081] FIG. 32 is a circuit diagram showing the arrangement of the
downward link switching circuit;
[0082] FIG. 33 is a table showing the correlation between the
basic-cabinet-side data and the extension-cabinet-side data in an
upward link switching circuit of each extension cabinet;
[0083] FIG. 34 is a circuit diagram showing the arrangement of the
upward link switching circuit;
[0084] FIG. 35 is a view showing the correlation between each
extension cabinet and the number of channels of downward link data
from the basic cabinet;
[0085] FIG. 36 is a view showing control data output from a
connection memory;
[0086] FIG. 37A is a view for explaining the first use example of a
digital attenuator arranged in a time switch section;
[0087] FIG. 37B is a view for explaining the second use example of
the digital attenuator arranged in the time switch section;
[0088] FIG. 37C is a view for explaining the third use example of
the digital attenuator arranged in the time switch section;
[0089] FIG. 38A is a view showing a display example upon depressing
a directory key;
[0090] FIG. 38B is a view showing a display example upon inputting
a directory number;
[0091] FIG. 38C is a view showing a display example upon inputting
an extension number;
[0092] FIG. 39A is a view showing the first operation and display
example associated with an inquiry for a directory number;
[0093] FIG. 39B is a view showing the second operation and display
example associated with an inquiry for a directory number;
[0094] FIG. 39C is a view showing the third operation and display
example associated with an inquiry for a directory number;
[0095] FIG. 39D is a view showing the fourth operation and display
example associated with an inquiry for a directory number;
[0096] FIG. 40A is a flow chart showing the procedure and contents
of call reception information storage control;
[0097] FIG. 40B is a flow chart showing the procedure and contents
of call reception information display control;
[0098] FIG. 41 is a view showing an example of a park reservation
table to be used for call park;
[0099] FIG. 42 is a flow chart showing a call park control
procedure by the RCTU;
[0100] FIG. 43 is a flow chart showing a repark control procedure
by the RCTU;
[0101] FIG. 44 is a flow chart showing a pickup control procedure
by the RCTU;
[0102] FIG. 45 is a flow chart showing a mode change control
procedure in the PCI-DI and the RCTU of the main unit;
[0103] FIG. 46 is a flow chart showing a holding display control
procedure;
[0104] FIG. 47 is a view showing an example of a holding
information area;
[0105] FIG. 48 is a view showing an order of blinking LEDs
corresponding to line selection keys;
[0106] FIG. 49 is a view showing an example of the arrangement of
DN keys;
[0107] FIG. 50 is a view schematically showing the first half of an
extension operation using DNs;
[0108] FIG. 51 is a view schematically showing the second half of
the extension operation using the DNs;
[0109] FIG. 52 is a view schematically showing an extension ring
transfer operation using the DNs;
[0110] FIG. 53 is a view schematically showing an ACB operation
using the DNs;
[0111] FIG. 54 is a view schematically showing an office line
calling operation and a ring transfer operation using the DNs;
[0112] FIG. 55 is a view schematically showing the first half of an
office line calling operation and a conference operation using the
DNs;
[0113] FIG. 56 is a view schematically showing the second half of
the office line calling operation and the conference operation
using the DNs;
[0114] FIG. 57 is a table showing an example of LED display of the
DN keys;
[0115] FIG. 58 is a table showing an operation performed when no DN
is available or when no DN key is available;
[0116] FIG. 59 is a table showing an example of processing
extension call reception during extension call reception using the
DNs;
[0117] FIG. 60 is a table showing an example of DND processing
during call reception;
[0118] FIG. 61 is a table showing a call forward operation using
the DNs;
[0119] FIG. 62 is a view showing an operation performed when the CF
destination is a phantom DN;
[0120] FIG. 63 is a view showing an LCD display example of the CF
when a plurality of CF destinations can be set from one
terminal;
[0121] FIG. 64 is a view showing the correlation between phantom
DNs and MW keys;
[0122] FIG. 65 is a view showing an LCD display example upon
receiving message waiting;
[0123] FIG. 66 is a view showing an LCD display example upon
transmitting message waiting;
[0124] FIG. 67 is a view showing an operation of receiving message
waiting to a primary DN;
[0125] FIG. 68 is a view showing an operation of receiving message
waiting to a phantom DN;
[0126] FIG. 69 is a view showing another operation of receiving
message waiting to a phantom DN;
[0127] FIG. 70 is a view showing an operation of transmitting
message waiting from a primary DN;
[0128] FIG. 71 is a view showing an operation of transmitting
message waiting from a secondary DN;
[0129] FIG. 72 is a view showing an operation of transmitting
message waiting from a phantom DN;
[0130] FIG. 73 is a view showing an ID sending operation to a voice
mail in message waiting;
[0131] FIG. 74 is a view showing the ID sending operation of a
voice mail in call forward;
[0132] FIG. 75 is a view showing a Buzz key operation;
[0133] FIG. 76 is a view showing the LED ON timing of a Buzz key
operation terminal, the LED ON timing of a Buzz called terminal,
and an MSG tone generation pattern;
[0134] FIG. 77 is a table showing the display example of office
line LEDs;
[0135] FIG. 78 is a table showing patterns of a display operation
when "I-Called" is displayed for a primary line;
[0136] FIG. 79 is a table showing patterns of a display operation
when call reception display is performed on a designated DN
independently of the presence/absence of a CO key upon receiving a
call;
[0137] FIG. 80 is a table showing the summary of operations in the
busy state;
[0138] FIG. 81 is a timing chart showing a delay call reception
operation in ring transfer for an extension HFU calling
destination;
[0139] FIG. 82 is a timing chart showing the delay call reception
operation in ring transfer for an extension tone calling
destination;
[0140] FIG. 83 is a timing chart when an on-hook operation is
performed during a tone calling delay operation;
[0141] FIG. 84 is a view showing an example of a speech
communication management record printed by an SMDR;
[0142] FIG. 85 is a view showing a DN call reception operation by
an available DN;
[0143] FIG. 86 is a view showing the DN call reception operation
during call reception when a DN is available;
[0144] FIG. 87 is a view showing an operation of the DN key during
call reception;
[0145] FIG. 88 is a view showing the DN call reception operation
during speech communication;
[0146] FIG. 89 is a view showing the DN call reception operation
during speech communication when a DN is available;
[0147] FIG. 90 is a view showing the DN call reception operation
during speech communication when no DN is available;
[0148] FIG. 91 is a view showing the transmission format of calling
line identification information sent from a public network using a
CLASS service;
[0149] FIG. 92 is a flow chart showing the procedure and contents
of a wiring mode start control;
[0150] FIG. 93 is a flow chart showing the procedure and contents
of a wiring mode end control;
[0151] FIG. 94 is a table showing the correlation between
operations using the DN keys and displayed symbols;
[0152] FIG. 95 is a view for explaining an extension speech
communication operation using the DN keys;
[0153] FIG. 96 is a view for explaining a CF destination DN setting
operation using a primary DN key;
[0154] FIG. 97 is a view for explaining the CF destination DN
setting operation using a phantom DN key;
[0155] FIG. 98 is a view for explaining a voice mail ID code
setting operation using the primary DN key;
[0156] FIG. 99 is a view for explaining the voice mail ID code
setting operation using the phantom DN key;
[0157] FIG. 100 is a flow chart showing the procedure and contents
of DN number display control;
[0158] FIG. 101 is a view showing an example of the connection DN
area map in a RAM;
[0159] FIG. 102 is a view for explaining the procedure of function
setting for keys of the DKT/EKT;
[0160] FIG. 103 is a view showing an example of the key arrangement
area map in the DKT/EKT;
[0161] FIG. 104 is a flow chart showing the procedure and contents
of camp-on tone sending control;
[0162] FIG. 105A is a chart showing the signal waveform of an
office line camp-on tone generated by the DKT/EKT;
[0163] FIG. 105B is a chart showing the signal waveform of an
extension camp-on tone generated by the DKT/EKT;
[0164] FIG. 105C is a chart showing the signal waveform of an
office line camp-on tone generated by a standard telephone; and
[0165] FIG. 105D is a chart showing the signal waveform of an
extension camp-on tone generated by the standard telephone.
BEST MODE OF CARRYING OUT THE INVENTION
[0166] FIG. 91 is a view showing a signal format used in a
communication network using a CLASS service. A modem signal is
inserted into the interval between the first bell signal and the
second bell signal of a ringing signal. This modem signal has a
format in which a synchronous signal consisting of a repetitive
pattern of "01" is arranged at the start position, a mark signal, a
message type word, a data word count, and a data portion
sequentially follow the synchronous signal, and a checksum is
arranged at the last position. Calling line identification
information is inserted into the data portion. The calling line
identification information contains "time", i.e., date and time,
"calling line ID", "reason for absence of DN", "name", and "reason
for absence of name".
[0167] FIG. 1 is a view showing the outer appearance of a digital
key telephone system according to an embodiment of the present
invention.
[0168] This system comprises a main unit (KSU) 1 connected to an
analog public network (PSTN) (not shown) through a subscriber line
(CO line), digital key telephones (DKTS) 2 connected to the
extension lines as extension terminals, a personal computer (PC) 3,
a standard telephone (STT) 4, a personal computer (PC) 6 connected
to the main unit 1 through a modem 5 as an external device, a
communication information management unit (MIS) 7 for
accumulating/managing communication information, and a
communication management recording unit (SMDR) 8 for printing a
communication management record or the like.
[0169] The main unit 1 is constituted by stacking one basic cabinet
1a and a plurality of (five in FIG. 1) extension cabinets 1b. The
basic cabinet 1a and the extension cabinets 1b are connected
through data cables (not shown). The basic cabinet 1a mainly
incorporates a control unit in addition to a power supply unit.
Each extension cabinet 1b mainly incorporates various interface
units in addition to a power supply unit. Each unit has a card
shape and is inserted into a slot on the mother board of each
frame.
[0170] FIG. 2 is a block diagram showing the arrangement of the
main unit 1.
[0171] The main unit 1 comprises an office line interface 11
(RCOU), a calling line identification information interface unit
(RCIU) 12, a digital key telephone interface unit (RDKU) 13, a
serial communication control unit (RSIU) 14, a standard telephone
interface unit (RSTU) 15, and a control unit (RCTU) 16. The
interface units 11 to 15 are connected to the control unit 16
through a data highway 17 and a PCM highway 18. The data highway 17
is used to perform control data transfer between the units. The PCM
highway 18 is used to transmit a digital speech communication
signal between the units.
[0172] The office line interface 11 of the main unit 1 also has a
leased line, a private branch exchange (PBX), and an interface (not
shown) connected to another key telephone system.
[0173] The central office line interface unit (RCOU) 11 performs an
office line interface operation for an analog public network NW,
e.g., call reception detection, polarity inversion detection,
opening/closing of a DC loop, dial sending, or the like under the
control of the control unit 16, and also performs processing of
converting an analog speech signal arriving via the subscriber line
(CO line) into a PCM signal or processing of converting a PCM
signal transferred from the control unit 16 into an analog speech
signal and sending the speech signal to the subscriber line.
[0174] FIG. 3 is a circuit diagram showing the arrangement of the
RCOU 11. As shown in FIG. 3, the RCOU 11 comprises an interface
circuit 110, a codec section 111, a time slot assigner 112, and a
control data communication microcomputer 113. The interface circuit
110 has a call reception detection circuit 110a connected to the
subscriber line, a polarity inversion circuit 110b, and a DC loop
circuit 110c. The call reception detection circuit 110a detects a
call signal arriving from the analog public network NW via the
subscriber line. The polarity inversion circuit 110b detects
polarity inversion which occurs on the subscriber line during the
call connection process. The DC loop circuit 110c closes the DC
loop in calling, transmits a dial pulse, and opens the DC loop at
the end of speech communication.
[0175] The codec section 111 has an A/D converter and a D/A
converter to perform PCM coding processing of converting a
transmission speech signal into PCM speech data and PCM decoding
processing of converting received PCM speech data into an analog
reception speech signal.
[0176] The time slot assigner 112 determines the timing of speech
data transmission between the codec section 111 and the PCM highway
18 on the basis of a predetermined time slot address, and a frame
synchronous signal and clock signal from the PCM highway 18, and
notifies the codec section 111 of this timing. The codec section
111 transmits/receives PCM speech data to/from the PCM highway 18
at the timing designated by the time slot assigner 112.
[0177] The control data communication microcomputer 113 monitors
detection signals from the call reception detection circuit 110a
and the polarity inversion circuit 110b and controls DC loop
opening/closing and dial pulse transmission in the DC loop circuit
110c. The control data communication microcomputer 113
transmits/receives control data associated with call reception
detection, polarity inversion detection, DC loop opening/closing,
and dial pulse transmission to/from the control unit 16 through the
control data highway 17.
[0178] The calling line identification information interface unit
(RCIU) 12 interfacing to the subscriber line has an arrangement
shown in FIG. 4. The RCIU 12 comprises a relay 120, a demodulation
circuit 121, a serial/parallel conversion section 122, a data
detection signal transmission section 123, a relay control section
124, a detection unit control section 125, and a memory 126. The
serial/parallel conversion section 122, the data detection signal
transmission section 123, the relay control section 124, and the
memory 126 are connected to the detection unit control section 125
through an internal data bus 127.
[0179] The demodulation circuit 121 receives a modulated signal
(notification data) arriving from the analog public network NW
through the subscriber line (CO line) and demodulates the signal to
detect calling line number identification information (caller ID).
The serial/parallel conversion section 122 converts the calling
line identification information output from the demodulation
circuit 121 as a serial signal into a parallel signal. The data
detection signal transmission section 123 sends the calling line
identification information output from the demodulation circuit 121
to the internal data bus 127. This notification data is transferred
from the detection unit control section 125 to the control unit 16
through the data highway 17.
[0180] The relay 120 is used to disconnect the RCIU 12 from the
subscriber line. The relay control section 124 controls the relay
120 to disconnect the RCIU 12 from the subscriber line and match
the impedance in dial sending or speech communication.
[0181] The detection unit control section 125 controls the calling
line number detection unit 12. The memory 126 is used as an
external storage section of the detection unit control section
125.
[0182] FIG. 4 shows only one set of units. When a plurality of CO
lines are led to the main unit 1, the relay 120, the demodulation
circuit 121, the serial/parallel conversion section 122, the data
detection signal transmission section 123, and the relay control
section 124 of the above circuits are arranged in units of CO
lines. That is, the RCIU 12 incorporates circuits equal in number
to the subscriber lines.
[0183] The digital key telephone interface unit (RDKU) 13 as an
interface between the main unit 1 and each digital key telephone
(DKT) 2 has an arrangement shown in FIG. 5.
[0184] The RDKU 13 has ping-pong transmission circuits 131l to 131n
corresponding to the number of extension lines. Each of the
ping-pong transmission circuits 131l to 131n performs ping-pong
transmission of speech or information terminal data and control
data between the RDKU 13 and a corresponding one of the digital key
telephones 2 by using a time division channel of a 2B+D scheme,
i.e., having two B channels (B1 and B2) with a transmission rate of
64 kbps and one D channel with a transmission rate of 16 kbps. The
ping-pong transmission circuit has a 2B+D generation section and a
2B+D separation section.
[0185] The 2B+D generation section synthesizes speech data and
information terminal data on downward link channels B1 and B2 from
the PCM highway 18 and control data on a downward link channel D
from a control data communication microcomputer 133 into a data
packet with a 2B+D format and transmits the data packet to each
digital key telephone 2. The 2B+D separation section separates an
upward link data packet arriving from each digital key telephone 2
into speech and information terminal data on the upward link
channels B1 and B2 and control data on the upward link channel D
and transfers the data to the PCM highway 18 and the control data
communication microcomputer 133.
[0186] The channel B1 is assigned to speech data transmission to
each digital key telephone 2 while the channel B2 is assigned to
transmit information terminal data when an information terminal
such as a personal computer is connected to each digital key
telephone 2.
[0187] A time slot assigner 132 receives a frame synchronous signal
and clock signal from the PCM highway 18 and notifies the ping-pong
transmission circuits 131l to 131n of the timing for
transmitting/receiving upward and downward link data on the B
channel to/from the PCM highway 18. Therefore, each of the
ping-pong transmission circuits 131l to 131n directly accesses the
PCM highway 18 at the timing designated by the time slot assigner
132 to transmit/receive upward and downward link data at a
transmission rate of 2.048 Mbps.
[0188] The control data communication microcomputer 133 monitors D
channel data transmitted/received by the ping-pong transmission
circuits 131l to 131n and controls to transmit/receive the D
channel data to/from the control unit 16 through the data highway
17.
[0189] The standard telephone interface unit (RSTU) 15 as an
interface between the main unit 1 and the standard telephone 4 has
an arrangement shown in FIG. 6. The RSTU 15 comprises a call signal
sending circuit 150, a DC supply circuit 151, and a dial detection
section 152. The call signal sending circuit 150 sends a 16-Hz call
signal generated by a call signal generation source 156 to the
standard telephone 4. The DC supply circuit 151 has a function of
detecting opening/closing the DC loop between the RSTU 15 and the
standard telephone 4 and supplies the detection signal to a
microcomputer 157. The DC supply circuit 151 also has a function of
feeding a prescribed DC voltage to the standard telephone 4 when
the DC loop is closed and inverting the polarity of this DC voltage
under the control of the microcomputer 157. The dial detection
section 152 detects a dial pulse sent from the standard telephone 4
and supplies the detection signal to the microcomputer 157.
[0190] The RSTU 15 also has a codec 154, and a time slot assigner
155 for designating the operation timing of the codec 154. The
codec 154 receives a transmission speech signal sent from the
standard telephone 4 through a transducer 153, converts the speech
signal into a PCM signal, and sends the PCM speech data to the PCM
highway 18. The codec 154 also converts speech data sent from the
PCM highway 18 into an analog speech signal and transmits the
speech signal to the standard telephone 4 through the transducer
153. The time slot assigner 155 determines the timing of speech
data transmission between the codec 154 and the PCM highway 18 on
the basis of a frame synchronous signal and clock signal from the
PCM highway 18 and designates the timing for the codec 154.
[0191] The microcomputer 157 ON/OFF-controls a call signal to the
call signal sending circuit 150, monitors DC loop opening/closing
detection and controls polarity inversion in the DC supply circuit
151, and monitors dial pulse detection in the dial detection
section 152. The microcomputer 157 also transmits/receives control
data to/from the control unit 16 through the data highway 17.
[0192] The serial communication control unit (RSIU) 14 for
connecting an external information device such as a personal
computer, the communication management recording unit (SMDR) 8, and
a printer 9 to the main unit 1 has an arrangement shown in FIG. 7.
The RSIU 14 has a plurality of (four in FIG. 7) serial
communication ports 1410 to 1413 and a control section 140. Of the
serial communication ports 1410 to 1413, the serial communication
port 1410 has only an RS232C driver/receiver (D/R) and is directly
connected to the serial I/O of the control section 140. Each of the
serial communication ports 1411 and 1412 has an RS232C
driver/receiver (D/R) 141b and an asynchronous transfer circuit
(UART: Universal Asynchronous Receiver Transmitter) 141a and
connects an external information device to a CPU bus 143 of the
control section 140 to transfer data.
[0193] The serial communication port 1413 has not only an RS232C
interface function but also a modem interface function. The serial
communication port 1413 has a modem 141c, a codec 141d, and a
switching circuit 141e in addition to the RS232C driver/receiver
141b and the UART 141a. The modem 141c and the codec 141d are used
for data transmission between the RSIU 14 and the PCM highway 18.
The switching circuit 141e switches connection between the UART
141a, the RS232C driver/receiver 141b, and the modem 141c in
accordance with a switching control signal from the control section
140.
[0194] The control section 140 is constituted by a one-chip CPU and
transmits/receives control data to/from the control unit 16 through
the CPU bus 143 having a dual port RAM 144. The control section 140
also controls to transfer communication data transmitted/received
by the serial communication ports 1410 to 1413 to another unit in
the main unit 1.
[0195] The control unit (RCTU) 16 for systematically controlling
the operation of the main unit 1 has an arrangement shown in FIG.
8. The control unit 16 has a main CPU 161 constituted by a
microprocessor. This main CPU 161 is connected to a ROM 162, a RAM
163, a local CPU 164, and a time switch section 165 through a bus
168.
[0196] The ROM 162 stores various programs or control data
necessary for switching control in advance. The RAM 163 is used to
store maintenance data, user data, or control data generated in
various control processes. The local CPU 164 controls control data
transfer between the main CPU 161 and the data highway 17.
[0197] The control unit 16 also has a tone data ROM 166 and a
parallel/serial conversion circuit (P/S) 167. The tone data ROM 166
reads out tone data representing a tone signal to be supplied to
the digital key telephones 2 and standard telephone 4 as extension
terminals in accordance with an instruction from the main CPU 161
during various services such as holding, transfer, or camp-on. The
parallel/serial conversion circuit 167 converts the tone data read
out from the tone data ROM 166 as a parallel signal into a serial
signal and sends the signal to the data highway 17.
[0198] The time switch section 165 performs time slot switching
processing between an upward link PCM highway 18a and a downward
link PCM highway 18b under the control of the main CPU 161.
[0199] FIG. 9 is a block diagram showing the arrangement of the
time switch section 165. The time switch section 165 comprises a
serial/parallel converter (S/P) 1651, a data memory 1652, a digital
attenuator section 1653, a multiplexer (MUX) 1654, and a
parallel/serial converter (P/S) 1655. The time switch section 165
also comprises a control register 1656, a connection memory 1657,
and a frame counter 1658.
[0200] Each time slot data transferred by the upward link PCM
highway 18a is converted from the serial signal into a parallel
signal by the S/P 1651, temporarily stored in the data memory 1652,
and then input to the digital attenuator section 1653. The digital
attenuator section 1653 has eight attenuators from -18 dB to +3 dB.
Every time slot data is input from the data memory 1652, one of the
attenuators is activated in accordance with control data output
from the connection memory 1657. The input time slot data is
gain-controlled by the activated attenuator and output.
[0201] The multiplexer 1654 shifts the time slot data output from
the digital attenuator section 1653 to the time slot of the
downward link PCM highway 18b in accordance with an instruction
from the connection memory 1657. The time slot data output from the
multiplexer 1654 is converted from the parallel signal into a
serial signal by the parallel/serial converter (P/S) 1655 and sent
to the downward link PCM highway 18b.
[0202] The frame counter 1658 generates a signal necessary for the
operation of the time switch section 165 on the basis of a clock
signal generated by a timing generation section (not shown) and a
frame signal from the PCM highway 18.
[0203] Each of the digital key telephones 2 has the following
arrangement. FIG. 10 is a plan view showing the outer appearance of
the digital key telephone 2. FIG. 11 is a block diagram showing the
circuit arrangement of the digital key telephone 2.
[0204] Referring to FIG. 10, a handset 22 is mounted on the cradle
portion of a telephone body 21. The operation panel of the
telephone body 21 has dial buttons 23, a plurality of flexible
buttons 24, a plurality of LED display devices 25 respectively
corresponding to the flexible buttons 24, a plurality of control
buttons 26, LED display devices 27 each corresponding to a
predetermined control button, and an LED display device 28.
[0205] Of the above operation buttons, the flexible buttons 24 are
used by the user to freely set various functions such as an office
line calling or automatic dialing. Examples of functions to be set
other than office line calling are leased line calling, automatic
dialing, pause, long pause, automatic redialing, saving, subaddress
sending, dial sending, privacy cancel, messaging, message
switching, message waiting, night switching, call reception
rejection, absence transfer, fixed absence transfer, camp-on,
pooling, park holding, call pickup, call answering, broadcasting,
microphone-off, hot line, and conference/transfer.
[0206] Leased line calling is used for calling in communication
between terminals connected to an intra-office communication
network.
[0207] For automatic dialing, the telephone numbers of parties to
be called are registered in a memory in advance in correspondence
with the flexible buttons. Depressing a flexible button allows
automatic calling to the corresponding called party.
[0208] Pause is a function of inserting a pause between, e.g., an
office line calling dial number and a called party dial number in
abbreviated dialing registration. Long pause is a function of
inserting a longer pause.
[0209] Automatic redialing is a function of automatically repeating
redialing when the called party is busy.
[0210] In saving, in a period from the end of the dialing operation
to the end of the speech communication, a flexible button for which
the save function is set is depressed to temporary store the dial
number of the called party. After the speech communication is
complete, automatic calling to the same called party is allowed by
depressing the flexible button for which the save function is
set.
[0211] Subaddress sending is a function used to designate one of a
plurality of communication terminal devices connected to one
digital line on the side of the other communication party connected
to the ISDN.
[0212] In dial sending, the dial number and subaddress of the
called party are input and then sent in calling to the ISDN.
[0213] Call reception rejection is a function of rejecting a call
from another extension line. When an extension terminal for which
call reception rejection is set is called, a busy tone with a
period shorter than that of a normal busy tone is returned.
[0214] Messaging is a function of registering a message for absence
answering in advance and sending the message to the calling line
upon receiving a call in absence of the called party. Message
switching is a function of selecting one of a plurality of messages
recorded in advance for absence answering.
[0215] Message waiting is a function of causing the called terminal
to display a message by designating it on the calling side when the
called party is busy or absent.
[0216] Night switching is a function of switching between extension
terminals for receiving a call in the daytime or weekdays and those
for receiving a call in the nighttime or holidays.
[0217] Absence transfer or fixed absence transfer is a function of
registering the extension number of a transfer destination in
advance, and when a call is received in the absence transfer mode,
automatically transferring the call to the transfer destination.
Absence transfer and fixed absence transfer are different in the
following points. In absence transfer, the user can register or
cancel the desired transfer destination anytime. In fixed absence
transfer, once the transfer destination is set at the time of
installation, it cannot be changed later. Transfer destination
setting for absence transfer can be made not only from the
extension terminal as the transfer source but also from another
extension terminal.
[0218] In camp-on, when a called extension terminal or office line
terminal is busy, the calling terminal sets camp-on and goes
on-hook. After the called terminal completes speech communication,
the calling terminal is notified of it. The calling terminal
automatically calls the called terminal upon off-hook. When the
called terminal answers the call, the called terminal and the
calling terminal are connected to allow speech communication.
[0219] In pooling, a number of accommodated office lines are
divided into groups, and each group is assigned to a pool. By
designating one pool, all office lines of the group assigned to the
pool can be selectively used. This function is effectively used
when there are a lot of office lines, and they cannot be
individually assigned to the flexible buttons. Park holding is a
function used to hold speech communication by using the pool.
Holding using no pool is performed by depressing a holding
button.
[0220] Call pickup or call answering is a function of answering an
office line call in an extension terminal by a one-touch or special
number operation when nobody answers the call. Call pickup and call
answering are different in the following points. In call pickup,
all office line calls can be answered. In call answering, however,
a plurality of office lines are divided into groups, and the call
answering function is set for different flexible buttons in units
of groups, thereby allowing call answering for each group.
[0221] Broadcasting is a function of voice-calling all extension
terminals or the extension terminals of a group. The microphone-off
function is used when the called party does not want to answer by
voice in broadcasting or group call. In this case, the microphone
for loudspeaking speech communication is turned off.
[0222] Privacy cancel is a function of adding a third party to
speech communication by a one-touch operation during office line
speech communication to allow conference speech communication.
[0223] Hot line is a function of calling a desired extension
terminal by a one-touch operation. During office line speech
communication, by depressing a flexible button for which the hot
line function is set, the call can be transferred by voice (call
transfer) or a transfer tone (ring transfer). By depressing a
flexible button for which conference/transfer is set when the
transfer destination party answers the call, the mode changes to an
office line conference mode. When the flexible button for which the
hot line is set is depressed during extension speech communication,
the extension speech communication is held. By depressing the
flexible button for which conference/transfer is set when the other
party of extension hot line answers the call, the mode changes to
the extension conference mode. When the handset goes on-hook in the
extension conference mode, the extension call is transferred.
[0224] Each of the digital key telephones 2 is constituted by a
speech communication circuit 200 and a control circuit 220, as
shown in FIG. 11.
[0225] Each of the digital key telephones 2 has, as speech
communication modes, a handset speech communication mode using the
handset 22 and a hands-free speech communication using a hands-free
loudspeaker 212 and a hands-free microphone 213.
[0226] When the handset speech communication mode is selected, a
transmission signal output from the microphone of the handset 22 is
input to a codec 203 through a transmission amplifier 207 and a
channel switch 208. When the hands-free speech communication is
selected, a transmission signal output from the hands-free
microphone 213 is input to the codec 203 through a transmission
amplifier 214 and a channel switch 215.
[0227] The codec 203 converts the input transmission signal into
speech communication data by PCM coding and supplies the speech
communication data to a ping-pong transmission circuit 202 as B1
channel data. The ping-pong transmission circuit 202 has a 2B+D
synthesis section. The 2B+D synthesis section synthesizes the B1
channel speech communication data with D channel control data
output from a speech communication control microcomputer 221 (to be
described later) to generate upward link transmission data having
the 2B+D format. This transmission data is sent to the RDKU 13
through a transducer 201.
[0228] Downward link transmission data having the 2B+D format,
which arrives from the RDKU 13, is input to the ping-pong
transmission circuit 202 through the transducer 201. The ping-pong
transmission circuit 202 has a 2B+D separation section. The 2B+D
separation section performs processing of separating the downward
link transmission data into B1 and B2 channel speech communication
data and D channel control data. The B1 channel speech
communication data is supplied to the codec 203. The D channel
control data is supplied to the speech communication control
microcomputer 221.
[0229] The codec 203 performs signal processing of PCM-decoding the
B1 channel speech communication data to reproduce the reception
signal. In the handset speech communication mode, the reception
signal is supplied to the loudspeaker of the handset 22 through a
channel switch 204, an attenuator 205, and a reception amplifier
206. In the hands-free mode, the reception signal is supplied to
the hands-free loudspeaker 212 through a channel switch 209, an
attenuator 210, and a reception amplifier 211 and output from the
loudspeaker 212.
[0230] The control circuit 220 has the speech communication control
microcomputer 221. The speech communication control computer 221
systematically performs all control operations associated with
speech communication while transmitting/receiving control data
to/from the main unit 1. The control contents include an operation
of detecting the operation information of the dial buttons 23, the
flexible buttons 24, the control buttons 26, and a hook switch 222,
OF/OFF-control of the plurality of LED display devices 25 and 27,
control of supplying display data to an LCD driving circuit 223 to
cause the LED display device 28 to display it, selective
ON/OFF-control of the channel switches 204, 208, 209, and 215 in
accordance with the speech communication mode, and control of
changing the attenuation amount of the attenuator 205 or 210 in
accordance with the operation amount of the volume control (not
shown).
[0231] A digital key telephone having a PC interface unit (PCI-DI)
2b has the following arrangement. FIG. 12 is a block diagram
showing the arrangement of the interface circuit.
[0232] The interface circuit comprises a telephone interface
section 230 and a computer interface section 240. The telephone
interface section 230 comprises a transducer 231, a ping-pong
transmission circuit 232, a speech communication control
microcomputer 233, and a selector 234. The ping-pong transmission
circuit 232 and the speech communication control microcomputer 233
have almost the same functions as those of the ping-pong
transmission circuit 202 and the speech communication control
microcomputer 221 described above with reference to FIG. 11.
[0233] The selector 234 selects one of speech communication control
data output from the speech communication control microcomputer 233
and data communication control data output from a data
communication control microcomputer 245 (to be described later) and
supplies the selected data to the ping-pong transmission circuit
232 as D channel data.
[0234] The computer interface section 240 has the following
arrangement.
[0235] B2 channel downward link transmission data separated by the
ping-pong transmission circuit 232 is converted from the serial
data into parallel data by a serial/parallel converter (S/P) 241.
The B2 channel downward link transmission data has eight bits (64
kbps). The six bits of these eight bits are assigned to
communication data RD (48 kbps), and the remaining two bits are
assigned to a reception carrier detection signal CD (8 kbps) and a
transmission enable signal CS (8 kbps) of the RS232C interface,
respectively.
[0236] In the 8-bit parallel data output from the S/P 241, the
6-bit reception data RD is converted into serial data by a
parallel/serial converter (P/S) 242 and then sent to the personal
computer 3 through a selector 243 and an R232C driver/receiver 244.
The reception carrier detection signal CD and the transmission
enable signal CS are sent to the personal computer 3 through the
driver/receiver 244 and also fetched by the data communication
control microcomputer 245.
[0237] Transmission data SD (48 kbps) sent from the personal
computer 3 is input to a serial/parallel converter (S/P) 246
through the RS232C driver/receiver 244 and a selector 248,
converted into parallel data, and input to a parallel/serial
converter (P/S) 247. Simultaneously, an RS232C interface
transmission request signal RS (8 kbps) and the transmission enable
signal CS (8 kbps) which are sent from the personal computer 3 are
input to the parallel/serial converter (P/S) 247.
[0238] For this reason, 8-bit serial data constituted by the
transmission data SD, the transmission request signal RS, and the
transmission enable signal CS is output from the P/S 247. This
serial data is supplied to the ping-pong transmission circuit 232
as B2 channel upward link transmission data. The ping-pong
transmission circuit 232 multiplexes it with the B1 channel upward
link speech communication data and D channel upward link control
data and sends the data to the RDKU 13 of the main unit 1.
[0239] The operation of the digital key telephone system having the
above arrangement will be described next.
[0240] (1) Various Operations Using Caller ID
[0241] (1-1) Reception and Call Reception Processing of Caller
ID
[0242] A caller ID is received by the RCIU 12. The RCIU 12 checks
the caller ID transmitted from the analog public network NW. Upon
confirming that the caller ID has been normally received, the RCIU
12 transfers the caller ID to the RCTU 16 through the data highway
17; otherwise, the RCIU 12 transfers an error code to the RCTU 16.
The RCTU 16 analyzes the caller ID transferred from the RCIU 12 and
extracts information such as the calling line name and calling line
number which are used for the subsequent call processing.
[0243] FIG. 13 is a timing chart showing the caller ID reception
operation. As shown in FIG. 91, the caller ID arrives at the
interval between the first ring (2 sec) and the second ring of a
ringing signal. When the ringing signal arrives, the RCIU 12
detects the end of the first ring of the ringing signal and then
waits for the arrival of the caller ID. The RCIU 12 sequentially
receives the channel seizure signal, the mark signal, and the
actual data, and finally, the checksum. Upon receiving all of these
signals, the RCIU 12 transfers these signals to the RCTU 16 through
the data highway 17.
[0244] When the start of reception of the first ring of the ringing
signal is detected, the RCTU 16 sets a privacy mode for the CO line
which has received the signal, thereby preventing congestion of
calling and call reception. The privacy mode is canceled upon
detecting the start of reception of the second ring of the ringing
signal. The caller ID is not always constituted by a piece of
information (message type) and may have a plurality of pieces of
information (a plurality of message types). Therefore, in receiving
the caller ID, the RCIU 12 confirms the message type and receives
all pieces of information.
[0245] The RCTU 16 analyzes the transferred caller ID to determine
the called telephone and causes the telephone to generate sound.
FIG. 14 is a flow chart showing the control procedure.
[0246] In step S14a, the RCTU 16 analyzes the caller ID to detect
the calling line number. In step S14b, the RCTU 16 accesses a table
memory storing the correlation between calling line numbers and
sound generation telephone numbers. In step S14c, it is determined
whether the called telephone number corresponding to the received
calling line number is stored.
[0247] FIG. 15 shows an example of the table memory which is
arranged in the RAM 163 shown in FIG. 8. The storage contents of
this table memory, i.e., the correlation between the calling line
numbers and the sound generation telephone numbers is set in
advance upon wiring installation. The user of an extension
telephone who has done the answering operation for the call
arriving from the CO line for the first time, including a transfer
operation to another extension telephone (RT: Ring Transfer), can
operate the extension telephone, as needed to change the sound
generation telephone number stored in the table memory to the self
extension telephone number. In addition, the sound generation
telephone number stored in the table memory can be automatically
rewritten to the number of the extension telephone which has
answered the call for the first time. Furthermore, in place of or
in addition to the calling line number, the name of the calling
line contained in the caller ID may be registered in the table
memory.
[0248] When it is determined in step S14c that the called telephone
number corresponding to the received calling line number or calling
line name is stored, the RCTU 16 advances to step S14d. The
telephone corresponding to the stored telephone number is
determined as the called telephone, and the RDKU 13 sends call
reception information to this telephone and causes it to generate
sound. If no corresponding called telephone number is stored, the
flow advances to step S14e to perform the normal call reception
operation. In the normal call reception operation, a repeater (ATT)
or a predetermined extension telephone receives the call.
[0249] Upon receiving the call reception information, the extension
telephone displays the calling line name, the number of the CO line
which has received the call, or the like on the LCD 28, as shown in
FIG. 16. In normal call reception to the repeater, the calling line
name, the number of the CO line which has received the call, and
the like are displayed on the LCD of the repeater, as shown in FIG.
17.
[0250] Assume that the user of the extension telephone which has
received the call temporarily answers the call and then transfers
it to another extension telephone, i.e., an RT (Ring Transfer)
operation is performed. In this case, the RCTU 16 causes an
extension telephone corresponding to the extension telephone number
as the transfer destination input by the transfer operation to
receive the call. In RT, the RCTU 16 sends the caller ID to the
extension telephone of the transfer destination, and the caller ID
is displayed on the LCD of the extension telephone of the transfer
destination. In recalling RT, the call is received by the extension
telephone of the transfer source again. At this time, the received
caller ID is displayed on the LCD of the extension telephone which
has received the call.
[0251] With the above operation, an optimum extension telephone
user can answer each calling line. For example, a terminal for
receiving and answering a call can be appropriately selected such
that a person in charge directly answers a call from an important
client while a secretary answers calls from other clients.
[0252] (1-2) Storage of Caller ID
[0253] If nobody answers the call from the CO line, and the calling
line quits calling, the received caller ID is stored in a storage
buffer allocated to each extension terminal.
[0254] Assume that nobody answers the call from the CO line, and
the calling line quits calling. Upon determining that the office
line call reception is restored, the RCTU 16 stores the received
caller ID in a storage buffer corresponding to the called extension
line in the buffer memory area in the RAM 163. In storing the
received caller ID, if the storage buffer has a free area, the
received caller ID is written in the free area. If no free area is
present, the received caller ID is overwritten on the oldest caller
ID. The caller ID to be stored has the calling line name (15
characters), the calling line number or ID code (10 digits), the
call reception date (8 digits), and the status (contents of storage
data or data reference condition).
[0255] If RT is performed, and the extension telephone of the
transfer destination does not answer the call, the received caller
ID is stored in the storage buffer corresponding to the extension
line of the transfer destination. In recalling the call transfer,
the received caller ID is stored in both the storage buffer of the
transfer source extension line and that of the transfer destination
extension line.
[0256] Assume that call forward (CF) has been set in the extension
telephone which has received the call. If a call is received by
another extension telephone, the extension telephone of the CF
destination does not answer the call, and calling is quitted, the
received caller ID is stored in the storage buffer corresponding to
the extension telephone of the CF source.
[0257] When only one extension telephone corresponds to the CO line
which has received the call, the caller ID is stored in the storage
buffer corresponding to this extension telephone. If two or more
extension telephones correspond to the CO line, the caller ID is
received in the buffer corresponding to a predetermined extension
telephone corresponding to the call reception CO line.
[0258] If a primary DN or a phantom DN is designated as a called
party, the caller ID is stored in the buffer corresponding to an
owner terminal corresponding to the DN.
[0259] By storing caller IDs in correspondence with the respective
extension telephones, the following effects can be obtained.
[0260] (1-2-1) The user of each extension telephone can refer to
the stored caller IDs by a read operation or delete them as needed.
That is, the user can generate and manage the list of necessary
caller IDs on the self extension telephone. If the list desired by
each user is to be managed on the main unit, the load on the main
unit increases.
[0261] (1-2-2) Call back (to be described later in detail) can be
performed using the stored data.
[0262] (1-2-3) The number of IDs to be stored can be arbitrarily
assigned to each extension telephone. For example, a large storage
area can be assigned to an extension line to be used by a secretary
to frequently receive a call, and a small storage area can be
assigned to an extension telephone set in a warehouse to rarely
receive a call. Therefore, the limited storage area of the storage
buffer can be effectively utilized.
[0263] (1-2-4) By allowing only a corresponding extension telephone
to read the caller IDs stored in the storage buffer or causing each
extension user to use a password, the privacy of the stored caller
IDs can be protected.
[0264] (1-3) Display of Stored Caller ID and Call Back
[0265] The stored caller IDs are used to confirm the calling line
or perform call back by the user operation.
[0266] Assume that the user of an idling extension telephone
operates, e.g., "mode key +62" to display the caller IDs. The
extension telephone shifts to a stored information display mode and
sends a caller ID display request to the RCTU 16. To end display,
e.g., "mode key +0" is operated.
[0267] Upon receiving the caller ID display request from the
extension telephone, the RCTU 16 first reads out, e.g., the latest
caller ID from the storage buffer corresponding to the extension
telephone, transfers the caller ID to the extension telephone of
the request source, and causes it to display the caller ID on the
LCD 28. Every time a scroll operation is performed on the extension
telephone, the RCTU 16 reads out the caller IDs from the storage
buffer one by one from the latest reception timing, transfers the
caller ID, and causes the extension telephone to display the caller
ID on the LCD.
[0268] When a call is received in the caller ID display, mode, the
extension telephone blinks the LED and generates sound while
keeping the caller ID displayed. Upon answering the call, the
extension telephone exits the stored information display mode.
After this, the display operation upon receiving a call is
performed on the LCD, as shown in FIG. 16.
[0269] Assume that an operation of accessing the CO line is
performed on the extension telephone in the caller ID display mode.
At this time, the RCTU 16 of the main unit 1 executes call back
control. FIG. 18 is a flow chart showing the procedure and contents
of the control.
[0270] When the DN key or CO key of the extension telephone is
depressed during display of the caller ID, the RCTU 16 detects this
operation in step S18c, and the flow advances to step S18d. In step
S18d, the caller ID being displayed is read out from the storage
buffer and saved in a dialing buffer. It is determined in step S18e
whether the line selected by the DN key or CO key is an ACC line
which can be used by a specific person or a general line which can
be used by anyone. If the line to be used is an ACC line, the
account code input by the user from the extension telephone is
received in step S18f and approved in step S18g. If the code is
approved, the flow advances to step S18h to capture the CO line to
be used for calling. In this state, when a trigger key (CLID key)
for sending an ID is depressed on the extension telephone, the flow
advances from step S18i to step S18j to read out the caller ID
saved from the dialing buffer and send the caller ID to the
captured CO line.
[0271] If the line to be used is a general line, the RCTU 16 omits
approval of the account code. The flow advances from step S18e to
step S18h to capture the line to be used. In this state, when the
CLID key is depressed on the extension telephone, the flow advances
from step S18i to step S18j to read out the caller ID from the
dialing buffer and send it to the CO line.
[0272] If the lowest cost route (LCR) function is set, the RCTU 16
performs processing of selecting the lowest cost route before
capturing the line to be used, and a call is sent to the selected
route.
[0273] As described above, automatic call back using the stored
caller ID is allowed. When a call has been received in the absence
of an extension telephone user, the user can perform call back only
by performing the call back request operation without performing
the dialing operation. Therefore, the user operation associated
with the call back operation can be simplified.
[0274] (1-4) Dump Output of Received Caller ID
[0275] The RCIU 12 has, as modes of transferring the received
caller ID to the RCTU 16, a normal mode of analyzing the received
caller ID and outputting the analysis result to the RCTU 16, and a
dump mode of directly transferring the received modem data to the
RCTU 16 without any processing for the purpose of
maintenance/inspection of the RCIU 12 itself. The RCIU 12 selects
one of the modes in accordance with a downward link transmission
code sent from the RCTU 16 through the data highway 17.
[0276] In the normal mode, the maintenance operator inputs a mode
change command from the maintenance personal computer to test the
operation of the RCIU 12. The RCTU 16 transmits a dump mode
switching code (00010001) to the RCIU 12 through the data highway
17, as shown in FIG. 19A. Upon receiving the dump mode switching
code, the RCIU 12 changes the self mode from the normal mode to the
dump mode, and then returns a dump mode start code (00010001) to
notify the RCTU 16 of the start of a dump output operation from the
next received data. After this, every time a ringing signal
arrives, modem data read from the modem port is directly
transferred to the RCTU 16. The RCIU 12 reads a predetermined
amount of dump data and outputs it to the RCTU 16 while storing the
dump data in the internal buffer. After a predetermined amount of
dump data is transmitted to the RCTU 16, the RCIU 12 waits for
transmission for a predetermined time in consideration of the time
required for the RCTU 16 to process the data. After this
predetermined time has elapsed, the next dump data in a
predetermined amount is transmitted.
[0277] When the test is complete, and the maintenance operator
inputs a mode change command, the RCTU 16 transmits a normal mode
switching code (00010000) to the RCIU 12 through the data highway
17, as shown in FIG. 19. Upon receiving the normal mode switching
code, the RCIU 12 changes the self mode from the dump mode to the
normal mode, and then returns a normal mode start code (00010000)
to notify the RCTU 16 of the start of analyzed data output from the
next received data as the normal operation. After this, every time
a ringing signal arrives, caller ID data read from the modem port
is analyzed, and the analysis result is transferred to the RCTU
16.
[0278] As described above, the RCIU 12 reads a predetermined amount
of dump data and transmits it to the RCTU 16 while storing the dump
data in the internal buffer. When the internal buffer is filled,
the dump mode is ended at that time point. A dump mode end code
(00010010) is transmitted to the RCTU 16 to notify it of the end of
the dump mode.
[0279] Although mode switching can be set in units of CO lines, two
or more lines are not simultaneously set in the dump mode. Upon
powering on (starting), the normal mode is set for all CO lines. At
this time, the normal mode start code (00010000) is not transmitted
from the RCIU 12 to the RCTU 16.
[0280] As described above, the RCIU 12 has the dump mode and is
changed from the normal mode to the dump mode, as needed. With this
arrangement, in maintenance/inspection, a fault occurrence position
can be detected using the caller ID arriving from the analog
telephone network. As a result, the fault can be relatively easily
and properly disconnected and determined, so a measure against the
fault can be appropriately and quickly taken.
[0281] (2) Various Operations Associated with Function Setting and
Maintenance of System
[0282] (2-1) Prevention of Congestion among A Plurality of Wiring
installation Terminals
[0283] The basic cabinet la of the main unit 1 has six slots S11 to
S16 for accommodating main interface units. Of the slots S11 to
S16, the slots S11 and S12 receive the RSIU 14 and the RDKU 13,
respectively. Wiring installation is normally performed using the
digital key telephone 2 connected to the sixth port of the RDKU
13.
[0284] However, when the user does not use the RSIU 14, the RDKU 13
is also connected to the slot S11. In this case, wiring
installation can also be performed from the digital telephone
connected to the sixth port of this RDKU 13. When two digital
telephones can perform wiring installation, wiring installation
from the two digital telephones may congest.
[0285] To prevent this, the RCTU 16 of the system of this
embodiment has a wiring installation regulation function.
[0286] More specifically, when wiring installation is to be
performed, the maintenance operator inputs a special number, e.g.,
"*#*#1*2*3" representing a wiring mode start request from the
digital telephone connected to the sixth port of the slot S11 or
S12.
[0287] As shown in FIG. 92, the RCTU 16 determines in step S92a
whether the digital telephone which has sent the wiring mode start
request is in the normal mode. If YES in step S92a, it is
determined in step S92b whether the wiring flag is OFF. If YES in
step S92b, the flow advances to step S92c to turn on the wiring
flag ON. In step S92d, the digital telephone which has sent the
wiring mode start request is set in the wiring installation mode.
After this, the digital telephone can perform an input operation
for wiring installation.
[0288] When the digital telephone which has sent the wiring mode
start request is not in the normal mode, or even in the normal
mode, the wiring flag is already ON, the wiring mode start request
is rejected. A message representing the reason for rejection is
sent from the RCTU 16 to the digital telephone of the request
source and displayed on the LCD 28.
[0289] Therefore, when the digital telephone connected to one of
the slots S11 and S12 is in the wiring mode, the digital telephone
connected to the other slot never changes to the wiring mode even
when it sends the wiring mode start request.
[0290] With this function, simultaneous function setting inputs
from a plurality of wiring installation terminals can be prevented,
and congestion of function setting processing from a plurality of
wiring installation terminals can be prevented.
[0291] Assume that, upon completing wiring installation, the
maintenance operator dials a special number, e.g., "##+hold key"
representing a wiring mode end request from the digital telephone.
As shown in FIG. 93, the RCTU 16 determines in step S93a whether
the digital telephone of the request source is in the wiring mode.
If YES in step S93a, the wiring flag is turned off in step S93b.
The digital telephone which has sent the wiring mode end request is
changed from the wiring mode to the normal mode.
[0292] (2-2) Error Prevention in Function Setting
[0293] In wiring, telephone numbers are set for the extension
ports, or functions are assigned to the buttons of the digital
telephone. Due to misunderstanding or erroneous input by the wiring
installation operator, one function may be set for a plurality of
ports, or a plurality of functions may be set for one port.
[0294] In the system of this embodiment, the following measure is
taken to prevent such erroneous function setting. When one function
is set for only one port after power-on, this setting is valid.
However, when one function is set for a plurality of ports, setting
for the port with the smallest ordinal number is valid, and that
for the remaining ports is invalid.
[0295] FIG. 20 is a flow chart showing the procedure and contents
of function setting determination processing upon powering on. In
steps S20a and S20b in FIG. 20, a port number and a temporary port
number are set at "0" as initial values. The temporary port number
means an area for directly saving functional setting contents. The
RCTU 16 detects a valid function and port number from this area and
uses them.
[0296] In step S20c, it is determined whether the port number
larger than the temporary port number. If NO in step S20c, the flow
advances to step S20f to validate the function set for the port
number. In step S20g, the port number is incremented by one, and it
is determined in step S20h whether all ports are processed. If
unprocessed ports remain, the flow returns to step S20b to set the
temporary port number at "0" again.
[0297] If YES in step S20c, the flow advances to step S20d to
determine whether the function set for the port number matches that
set for the temporary port. If YES in step S20d, it is determined
that one function is set for a plurality of ports, or this function
is already valid for the temporary port number. In step S20g, the
port number is incremented by one, and the flow advances to
determination processing of the next port. If NO in step S20d, the
temporary port number is incremented by one in step S20e. The flow
returns to step S20c to repeat processing from step S20c.
[0298] Function setting change during the operation of the system
will be described next. In this case, when the function newly set
for an arbitrary port does not work at any other ports, the new
function setting for the port is valid. However, when the newly set
function already works at another port, the newly set function is
regarded as temporary setting, and the function set for another
port is made to continuously work. In this state, upon powering on
again, one function is set for a plurality of ports, so the
function set for the port with the smallest ordinal number is
valid.
[0299] FIG. 21 is a flow chart showing the procedure and contents
of determination processing when function setting is performed
during the operation of the system. In step S21a in FIG. 21, the
temporary port number is set at "0" as an initial value. In step
S21b, it is determined whether the temporary port number matches
the port number to be changed. If NO In step S21b, it is determined
in step S21c whether the function at the temporary port number
equals the function to be changed. If YES in step S21c, the newly
set function works at another port. Function determination
processing is ended. If NO in step S21c, the flow advances to step
S21d to increment the temporary port number by one. If YES in step
S21b, the flow advances to step S21d to increment the temporary
port number by one.
[0300] When the temporary port number is incremented by one, the
flow advances to step S21e to determine whether all ports are
checked. If unchecked ports remain, the flow returns to step S21b
to repeat the above determination processing. If YES in step S21e,
the newly set function works at any other ports. The flow advances
to step S21f to validate the function set for the port number to be
changed.
[0301] With this function, even when functions with different
contents are set from the personal computer, one of the functions
is validated in accordance with a predetermined rule. For this
reason, even when a plurality of inconsistent functions are set,
the system can be prevented from erroneously operating.
[0302] (2-3) Switching of Connection Interface in RSIU 14
[0303] As shown in FIG. 7, the RSIU 14 has the serial communication
port 1413 with the RS232C interface function and the modem
interface function, which switches these functions by the switching
circuit 141e. The serial communication port 1413 is used in the
following forms.
[0304] To use the serial communication interface function, the
switching circuit 141e is set to the RS232C driver/receiver 141b
side in accordance with a switching instruction from the RCTU 16,
as shown in FIG. 22. The personal computer 3 as an external
information device is connected to the RSIU 14. For this reason,
the user can set the function of the system or confirm the set
information in the system by using the personal computer 3.
[0305] To use the modem interface function, the switching circuit
141e is set to the side of the modem 141c and the codec 141d in
accordance with an instruction from the RCTU 16, as shown in FIG.
23. The personal computer 3 as an extension terminal device is
connected to the RSIU 14 through the PCM highway 18 and the RDKU
13. For this reason, the user can perform function setting by using
the personal computer serving as an extension terminal device. This
use form can be set by inputting a command from the personal
computer 3 as an extension terminal device to the RCTU 16.
[0306] Another example of use of the modem interface function is
shown in FIG. 24. The main unit 1 is called from the personal
computer 3 in a remote site through the analog telephone network
NW. After the response of the main unit 1, a command is input from
the personal computer 3 to the RCTU 16. A switching instruction is
sent from the RCTU 16 to the RSIU 14, and accordingly, the
switching circuit 141e in the RSIU 14 is switched to the side of
the modem 141c and the codec 141d. Subsequently, the personal
computer 3 in the remote site is connected to the RSIU 14. The user
can set the function of the system or confirm the set information
in the system by using the personal computer 3.
[0307] As a result, data can be transmitted/received not only
to/from the personal computer 3 connected to one of the serial
communication ports 1410 to 1413 as an external information device
but also to/from a personal computer connected as an extension
terminal device or a personal computer in a remote site, which is
connected through the analog telephone network NW.
[0308] (2-4) Loop Back Transfer in RSIU 14
[0309] The RSIU 14 has a loop back function for the RS232C port. As
shown in FIG. 7, the RSIU 14 has a normal mode wherein data sent
from the personal computer 3 is received by one of the serial
communication ports 1410 to 1413 and then transferred to the RCTU
16 through the CPU bus 143 and the dual port RAM 142, and a loop
back mode wherein data sent from the personal computer 3 is
received by one of the serial communication ports 1410 to 1413,
temporarily stored in the RAM 142 through the CPU bus 143, and then
read out and transmitted from one of the serial communication ports
1410 to 1413 to the personal computer 3 of the data transmission
source. Data transmission control in these modes is performed by
the control section 140 in accordance with an instruction from the
RCTU 16.
[0310] By using this function, the operation of, e.g., the main
unit 1 can be evaluated. A personal computer having an evaluation
function is connected to one of the serial communication ports 1410
to 1413. Evaluation data is transmitted from the personal computer
while the transmission mode of the RSIU 14 is set in the normal
mode and in the loop back mode.
[0311] In the normal mode, the evaluation data is received by the
serial communication port, transferred to the RCTU 16 through the
CPU bus 143, returned from the RCTU 16 to the RSIU 14 through the
CPU bus 143, and then returned from the serial communication port
to the personal computer of the evaluation data transmission
source.
[0312] To the contrary, in the loop back mode, the evaluation data
is received by the serial communication port, temporarily stored in
the RAM 143 through the CPU bus 143, and then read out and returned
from the serial communication port to the personal computer of the
evaluation data transmission source.
[0313] The personal computer analyzes the evaluation data returned
in both the modes and compares the data. It is determined on the
basis of the analysis result whether a fault is present in the RSIU
14 itself or another unit such as the RCTU 16.
[0314] (2-5) Confirmation of Operation of Arbitrary Unit in Main
Unit 1
[0315] The system of this embodiment can individually evaluate the
operation of an arbitrary unit in the main unit 1. A monitor unit
is connected to one of the serial communication ports 1410 to 1413
in the RSIU 14. A unit to be evaluated is individually selected
from the units such as the RCOU 11, the RCIU 12, the RDKU 13, the
RSTU 15, and the like. An evaluation unit is connected to the
selected unit to supply evaluation data. The evaluation data is an
ASCII code or a command for remote maintenance of the main unit,
which is input from a personal computer.
[0316] The unit to be evaluated operates in accordance with the
evaluation data. Data generated by the operation is transferred to
the RCTU 16 through the data highway 17 and then transmitted from
the RCTU 16 to the monitor unit through the RSIU 14. The monitor
unit displays or prints the operation result data transmitted from
the main unit 1. Therefore, the inspector or maintenance operator
of the product can evaluate the operation state of the unit to be
evaluated on the basis of the data displayed on or printed by the
monitor unit.
[0317] For example, in the normal mode, a command for remote
maintenance is input. If normal response data is returned from the
main unit and displayed on the monitor unit, it is determined that
the unit to be evaluated is normal. However, when abnormal response
data is returned, the loop back mode is set, and an arbitrary ASCII
code is input from the personal computer. If this input ASCII code
is returned and displayed on the display of the personal computer
without any change, it is determined that the data transmission
system between the personal computer and the main unit is normal.
In this case, it is determined that the remote maintenance program
of the main unit has a problem. If the input ASCII code is not
returned or displayed on the display, it is determined that the
data transmission system between the personal computer and the main
unit is abnormal.
[0318] (2-6) Wiring Installation of Transmission Rate for Serial
Communication Ports 1410 to 1413 in RSIU 14
[0319] The total data transmission rate provided by the RSIU 14 is
set at, e.g., 9,600 bps. When a transmission rate is permanently
assigned to the serial communication ports 1410 to 1413 within this
range of the total transmission rate, the transmission rate is
2,400 bps. However, all serial communication ports are not always
connected to personal computers. In this case, the transmission
capability of the RSIU 14 is partially unused.
[0320] To prevent this, in the system of this embodiment, the RSIU
14 has a function of assigning and controlling an adaptive data
transmission rate. The RSIU 14 stores a table storing the
correlation between the number of ports to be used and the data
transmission rate in the RAM 142. FIG. 25 shows an example of the
table storing the correlation between the number of ports to be
used and the data transmission rate. In wiring installation, the
control section 140 assigns a transmission rate to each port. Every
time a transmission rate is assigned, it is checked with reference
to the table whether the total transmission rate does not exceed
9,600 bps. If the total transmission rate exceeds 9,600 bps, the
user is notified of the error. The user checks transmission rate
setting for the remaining ports and reassigns a transmission rate
to the target port. If the sum of the assigned transmission rates
is equal to or smaller than 9,600 bps, this wiring installation is
valid.
[0321] A total of five types of external connection devices can be
connected to the serial communication ports 1410 to 1413: a
teletype (TTY), a communication management recording unit (SMDR), a
communication information management terminal (MIS), an SMDI, and a
CLASS/O.A. When the user determines the type of unit to be
connected, i.e., the use purpose of a port, the communication
scheme such as a bit length, i.e., the transmission attribute is
automatically determined by the control section 140. FIG. 26 shows
the correlation between the use purpose and the communication
scheme.
[0322] In starting for the first time, the first port 1410 is set
for a TTY to allow an operation at 2,400 bps while the remaining
ports are set in an inoperative state. If wiring installation has
been performed upon powering on, the wiring set value has priority.
Therefore, the user can perform wiring installation by using the
first port without setting a port to be exclusively used for wiring
installation. With this arrangement, the user can always grasp the
transmission rate and is not confused anymore.
[0323] Presence of the same use purpose at a plurality of ports is
inhibited. If a plurality of ports have the same use purpose, the
port with the smallest ordinal number has priority over the
remaining ports, and ports with larger ordinal numbers are
neglected. This determination is done by the RCTU 16 when the unit
is inserted.
[0324] (2-7) Determination of Capacity (Power Factor) of Units and
Extension Terminals in System Installation
[0325] In the conventional power factor determination, the engineer
manually calculates the power factor of each unit or digital
telephone to be mounted, and the obtained value is collated with
the sum of power factors of the system, thereby determining whether
the connection capacity of the units and digital telephones is
appropriate. For this reason, power factor determination takes much
labor and time.
[0326] In the system of this embodiment, the RCTU 16 detects the
power factor of each of the units mounted in the main unit 1 and
the digital telephones 2 connected to the RDKU 13 to calculate the
sum. The calculated value is collated with the rated value of the
power factor of the system, e.g., 24 V/70 mA. If the resultant
value exceeds the rated value, a warning message is sent to the
digital telephone or personal computer for wiring installation and
displayed on the LCD.
[0327] Even when a number of extension terminals beyond the
prescribed value of the power factor are to be connected by the
engineer or the like, he/she is warned of it by the message.
Therefore, mounting and connection of a number of units and
extension terminals beyond the prescribed value of the power factor
can be prevented.
[0328] (2-8) Connection between Basic cabinet 1a and Extension
cabinet 1b
[0329] As shown in FIG. 1, the main unit 1 is constituted by
stacking a plurality of extension cabinets 1b on the basic cabinet
1a and connecting the basic cabinet 1a to the extension cabinets 1b
through data cables. The data transmission format between the basic
cabinet 1a and each extension cabinet 1b is individually set on the
basic cabinet 1a side in advance in accordance with the stacking
position of the basic cabinet.
[0330] Assume that each extension cabinet 1b has four slots A, B,
C, and D. Let BA, BB, BC, and BD be downward link data transmitted
from the basic cabinet 1a to the slots A, B, C, and D. The number
of channels of these downward link data BA, BB, BC, and BD changes
for each extension cabinet 1b, as shown in FIG. 35. In FIG. 35, EA,
EB, EC, and ED represent data names in each extension cabinet
1b.
[0331] For this reason, each extension cabinet 1b must have a
unique data transmission function according to its stacking
position. In this case, however, extension cabinets of different
types corresponding to the number of stages must be prepared, and
common extension cabinets cannot be used, resulting in an increase
in cost of the system.
[0332] The system of this embodiment solves this problem in the
following manner. A cabinet position recognition signal is sent
from the basic cabinet 1a to each extension cabinet 1b, and the
extension cabinet 1b recognizes its stacking position on the basis
of the cabinet position recognition signal. In accordance with the
recognized frame stacking position, an interframe transmission
channel for signal transmission between the extension cabinet and
the basic cabinet 1a and an intraframe transmission channel for
signal transmission between the slots of the self frame are
switched, and the number of time slots of each channel is
converted.
[0333] FIG. 27 is a view showing the connection structure between
the basic cabinet 1a and the extension cabinets 1b. FIG. 28 is a
block diagram showing the arrangement of a connection interface
circuit. In FIGS. 27 and 28, only two of a plurality of (five in
FIG. 1) extension cabinets 1b are illustrated for the descriptive
convenience.
[0334] As shown in FIG. 27, a mother board 1a1 of the basic cabinet
1a has connectors 1a21 and 1a22 for connecting extension cabinets.
Relay boards 1b12 and 1b22 of extension cabinets 1ba and 1b2 have
relay boards 1b12 and 1b22 in addition to various units 1b13 and
1b23 such as the RDKUs 13, respectively. The relay boards 1b12 and
1b22 also have connectors 1b16 and 1b26, respectively. The
connectors 1b16 and 1b26 are connected to the connectors 1a21 and
1a22 of the basic cabinet 1a through data cables 1c1 and 1c2,
respectively.
[0335] The relay boards 1b12 and 1b22 have cabinet position
recognition circuits 1b14 and 1b24 and channel switching circuits
1b15 and 1b25, respectively. The cabinet position recognition
circuits 1b14 and 1b24 recognize the stacking positions of the self
frames on the basis of cabinet position recognition signals sent
from the basic cabinet 1a through the data cables 1c and 1c2 and
notify the channel switching circuits 1b15 and 1b25 of the
recognized cabinet position information. The cabinet position
recognition signal is, e.g., a 2-bit signal generated by
selectively connecting two signal lines to the power supply (5V)
and the ground terminal on the mother board 1a1 of the basic
cabinet 1a or generated by the control unit 16.
[0336] FIG. 29 is a table showing the correlation between the
extension cabinets 1b l and 1b2, cabinet position recognition
signals AS-1 and AS-2, and a data channel switching signal CS (to
be described later). FIG. 30 shows the circuit arrangement of each
of the cabinet position recognition circuits 1b14 and 1b24. Each
cabinet position recognition circuit is constituted by an exclusive
OR circuit, an inverter circuit, a pull-up circuit, and a pull-down
circuit. This circuit generates inverted cabinet position
recognition signals AS-1/ and AS-2/ and the data channel switching
signal CS in accordance with the input logic levels of the cabinet
position recognition signals AS-1 and AS-2.
[0337] Each of the channel switching circuits 1b15 and 1b25 has a
downward link switching circuit for channel-switching downward link
data from the basic cabinet 1a to downward link data for a
corresponding one of the extension cabinets 1b1 and 1b2 and an
upward link switching circuit for channel-switching upward link
data sent from each slot of the extension cabinet 1b1 or 1b2 to
upward link data for the basic cabinet la on the basis of the
cabinet position recognition signals AS-1/ and AS-2/ and the data
channel switching signal CS output from a corresponding one of the
cabinet position recognition circuits 1b14 and 1b24.
[0338] FIG. 32 shows an arrangement of the downward link switching
circuit. This circuit has a plurality of gate circuits which are
turned on/off in accordance with the cabinet position recognition
signals AS-1/ and AS-2/. These gate circuits switch the downward
link data BA, BB, and BC sent from the basic cabinet 1a to the
downward link data EA, EB, EC, and ED for the slots A, B, C, and D
in the extension cabinets 1b l and 1b2. FIG. 31 shows the
correlation between the basic cabinet side data BA, BB, and BC and
the extension cabinet side data EA, EB, EC, and ED in the downward
link switching circuits of the extension cabinets 1b1 and 1b2.
[0339] FIG. 34 shows an arrangement of the upward link switching
circuit. This circuit has three gate circuits which are turned
on/off in accordance with the cabinet position recognition signals
AS-1/ and AS-2/ and the data channel switching signal CS/, three
pull-up circuits for pulling up the output terminals of the gate
circuits, and three AND gates which are turned on in accordance
with the output signals from the gate circuits. Upward link data
sent from the slots A, B, C, and D in the extension cabinets 1b1
and 1b2 are switched to the upward link data BA, BB, and BC to the
basic cabinet 1a in accordance with the cabinet position
recognition signals AS-1/ and AS-2/ and the data channel switching
signal CS/. FIG. 33 shows the correlation between the basic cabinet
side data BA, BB, and BC and the extension cabinet side data EA,
EB, EC, and ED in the upward link switching circuits of the
extension cabinets 1b l and 1b2.
[0340] With this arrangement, the extension cabinets 1b1 and 1b2
recognize the self stacking positions on the basis of the cabinet
position recognition signals AS-1 and AS-2 from the basic cabinet
1a. In accordance with the recognition result, the transmission
data channel between the basic cabinet 1a and the slots A, B, C,
and D in each of the extension cabinets 1b1 and 1b2 is switched.
That is, the extension-cabinets 1b1 and 1b2 autonomously execute
channel switching according to their stacking positions. For this
reason, the extension cabinets 1b1 and 1b2 can have a common
arrangement, and the cost of the extension cabinet can be
reduced.
[0341] In the above description, the cabinet position recognition
circuits 1b14 and 1b24 and the channel switching circuits 1b15 and
1b25 are mounted on the relay boards 1b12 and 1b22, respectively.
However, these circuits may be directly mounted on mother boards
1b11 and 1b21.
[0342] (3) Characteristic Operation in Sending/Receiving Call and
in Communication
[0343] (3-1) Level Control for DTMF Signal When a dialing signal is
to be sent from the main unit 1 to the public network NW, a DTMF
signal is used. At this time, a signaling tone is sent to the
calling digital key telephone 2 in synchronism with the DTMF signal
sending operation to the public network NW. The signaling tone also
uses a DTMF signal. However, the level of the DTMF signal as the
signaling tone is set to be lower than that of the DTMF signal sent
to the public network NW as the dialing signal. For this purpose,
conventionally, a tone oscillator for generating a DTMF signal as a
dialing signal and a tone oscillator for generating a DTMF signal
as a signaling tone are independently arranged. A dialing signal
and a signaling tone each having an appropriate signal level are
sent by biasing the tone oscillators. With this arrangement,
however, two tone oscillators having the same arrangement are
required, resulting in a complex and expensive unit.
[0344] In the embodiment of the present invention, the time switch
section 165 in the control unit 16 has the digital attenuator
section 1653, as shown in FIG. 9. The digital attenuator section
1653 has eight attenuators from -18 dB to +3 dB. Every time slot
data is input from the data memory 1652, one of the attenuators is
activated in accordance with control data output from the
connection memory 1657, so that the input time slot data is
gain-controlled by the activated attenuator and output.
[0345] FIG. 36 shows an example of control data output from the
connection memory 1657. Control data output from the connection
memory 1657 has eight bits (DO to D7). The signal bits D4 to D6 are
used as bits for selecting one of the eight attenuators. The signal
bit D3 is used to select one of the .mu./L rule and the A/L rule as
a coding rule. The .mu./L rule is a PCM coding rule mainly used in
the North America and Japan. The A/L rule is a PCM coding rule
mainly used in England or the Southeast Asia. By allowing selection
of one of the rules, a time switch of certain type can be used in
any countries employing different coding rules.
[0346] The signal bit DO is used to control the data output from
the data memory 1652 or the multiplexer 1654 in units of channels.
The signal bit D2 is used to select one of the switching mode and
the message channel mode.
[0347] With this arrangement, when a dialing signal consisting of a
DTMF signal is to be sent to the public network NW in response to a
calling request from the digital telephone key DKT, a DTMF signal
generated from a tone generator is inserted into two different time
slots and input to the time switch section 165, as shown in FIG.
37A. In the time switch section 165, an attenuator is selected at
the switching timing of the first slot of the two time slots to
apply an attenuation amount for a dialing signal to the DTMF
signal. The DTMF signal in the first time slot is supplied with the
attenuation amount for a dialing signal by the attenuator,
transferred to the RCOU 11, and sent from the RCOU 11 onto the CO
line toward the public network NW. When the signal sending
destination is a CO line, an attenuation amount of -15 dB is
inserted.
[0348] At the switching timing of the second slot, an attenuator is
selected to apply an attenuation amount for a signaling tone. The
DTMF signal in the second time slot is supplied with an attenuation
amount for a signaling tone, i.e., an attenuation amount larger
than that for the dialing signal by the attenuator, transferred to
the RDKU 13, and sent from the RDKU 13 to the calling digital key
telephone DKT. The above attenuation amount is not inserted during
speech communication between the extension line and the CO line. An
attenuation amount of 8 dB is inserted for speech communication
between extension lines.
[0349] That is, on the basis of a common DTMF signal generated by
one tone generator, a DTMF signal having a signal level suitable
for a dialing signal and a DTMF signal having a signal level
suitable for a signaling tone are generated and sent to the public
network NW and the calling digital key telephone DKT. For this
reason, two DTMF generators having different output signal levels
need not be prepared, so the circuit arrangement can be simplified
and reduced in size, resulting in cost reduction of the main
unit.
[0350] The attenuation amount insertion timing by the attenuator is
limited to the signal sending timing. For example, in calling the
CO line, the attenuation amount is inserted only during the dialing
input period. After the dialing input period, attenuation amount
insertion is canceled.
[0351] Even when speech communication is performed between the
digital key telephones DKT through the main unit 1, as shown in
FIG. 37B, or speech communication is performed between office lines
through the main unit 1, as shown in FIG. 37C, the speech
communication signal level can be changed using the signal level
changing function of the time switch section 165. For example, when
the received volume from the other party of speech communication is
too small to catch the words, the reception-side speaker performs
an operation of increasing the reception level on the self digital
key telephone. Control data having a received volume increasing
request is sent from the digital key telephone to the main unit 1.
In response to the request of the control data, the main unit 1
changes the attenuation amount of the digital attenuator section
1653 in the time switch section 165 to a smaller one at the
switching timing of the time slot where the reception signal for
the digital key telephone of the request source is inserted. With
this operation, the volume of the reception signal for the digital
key telephone of the request source is increased, and the speaker
can obtain a satisfactory reception quality to catch the words.
[0352] (3-2) Differentiation of Camp-on Tone
[0353] The digital key telephone system according to the present
invention has a camp-on function. The camp-on function will be
described below.
[0354] By employing a multi DN function, various calls are received
at DN keys. In this case, if there is an available DN key, a call
is received at this DN key. However, if all DN keys are used, the
call is not received and waits for an available DN key. At this
time, the main unit send a tone signal to the called DKT and causes
it to output a tone, thereby notifying the DKT user of call
reception. The tone output from the DKT at this time is called a
camp-on tone. The camp-on is called office line camp-on when a call
is received by an office line, or extension camp-on when an
extension line receives a call.
[0355] It is very convenient for the user if he/she can determine
office line call reception or extension call reception only by
listening to the output camp-on tone. The reason for this is as
follows. When a new call is received by the office line during
extension speech communication, the extension speech communication
is immediately ended to answer the call on the office line because
the call is from outside the company. If the call is received by
the extension line, the extension speech communication can be
continued such that the new call is answered after the end of the
extension speech communication because the call is made inside the
company. As described above, calls can be coped with in different
manners.
[0356] However, conventionally, only a predetermined type of tone
signal is used as the camp-on tone. For this reason, the user
cannot determine the called line, i.e., the office line or the
extension line only from the camp-on tone.
[0357] According to the present invention, in camp-on, the main
unit 1 determines extension call reception or office line call
reception, and the camp-on tone to be sent from the main unit 1 to
the called DKT 2 in the busy state is changed in accordance with
the determination result.
[0358] For example, for a call from the extension line, an
unmodulated beep tone having a frequency of 2,000 Hz is sent to the
called DKT 2 in the busy state using an intermittent pattern of
1-sec ON and 3-sec OFF. For a call from the office line, a beep
tone having a frequency of 2,000 Hz and modulated at 10 Hz is sent
to the called DKT 2 using an intermittent pattern of 1-sec ON and
3-sec OFF.
[0359] The arrangement for generating the camp-on tone changes
depending on whether the called terminal is the DKT/EKT 2 or the
standard telephone (STT) 4. The DKT/EKT 2 incorporates a beep tone
(2 KHz) sound source. Therefore, when the called terminal is the
DKT/EKT 2, the main unit 1 sends a command for instructing output
of a camp-on tone for extension call reception or a command for
instructing output of a camp-on tone for office line call reception
to the DKT/EKT.
[0360] To the contrary, the standard telephone 4 has no beep tone
sound source. For this reason, when the called terminal is the
standard telephone 4, the main unit 1 must generate a camp-on tone
by itself, mix or insert the camp-on tone into a speech
communication signal, and send it to the standard telephone 4. In
the main unit 1 of the present invention, the main CPU 161 controls
the time switch section 165 in the control unit 16 to connect a
sound source channel to the channel for the standard telephone 4 in
a predetermined time.
[0361] FIG. 104 is a flow chart showing the procedure and contents
of the above-described camp-on sending control. Every time a
calling request arrives from the office line (CO line) or the
extension line, the RCTU 16 of the main unit 1 determines in step
S104a whether the called terminal is busy. If YES in step S104a,
the flow advances to step S104b to determine whether the called DN
is a DN being used. If YES in step S104b, the flow advances to step
S104c to determine the call reception type.
[0362] If it is determined in step S104c that a call from the
office line is received, the flow advances to step S104d to
determine whether the called terminal is the standard telephone
(STT) 4 or the DKT/EKT 2. If the terminal is the DKT/EKT 2, a
command for instructing generation of a camp-on tone for office
line call reception is sent to the called DKT/EKT 2 in step S104e.
In the called DKT/EKT 2 in the busy state, the internal sound
source is driven in accordance with the command to generate a
camp-on for office line call reception and notify the user of the
call reception. As the camp-on tone to be used at this time, a beep
tone having a frequency of 2,000 Hz and modulated at 10 Hz is
generated using an intermittent pattern of 1-sec ON and 3-sec OFF.
FIG. 105A shows the signal waveform.
[0363] When the called terminal is the standard telephone 4, the
flow advances to step S104f. The RCTU 16 drives a sound source
channel for tone generation which is arranged in the main unit 1.
The time switch section 165 is controlled to connect the sound
source channel to the reception channel of the called standard
telephone 4 intermittently at a predetermined period for office
line call reception. Therefore, the camp-on tone for office line
call reception, which is generated by the main unit 1, is mixed or
inserted into the reception signal, sent to the standard telephone
4, and output from the reception loudspeaker together with the
reception tone. As the camp-on tone to be output at this time, a
beep tone having a frequency of 1,200 Hz and modulated at 4 Hz is
generated using an intermittent pattern of 1-sec ON and 3-sec OFF.
FIG. 105B shows the signal waveform.
[0364] If a call is received from the extension line, the flow
advances from step S104c to step S104g. The RCTU 16 determines
whether the called terminal is the standard telephone (STT) 4 or
the DKT/EKT 2. If the terminal is the DKT/EKT 2, a command for
instructing generation of a camp-on tone for extension call
reception is sent to the called DKT/EKT 2 in step S104h. In the
called DKT/EKT 2 in the busy state, the internal sound source is
driven in accordance with the command to output a camp-on for
extension call reception and notify the user of the call reception.
As the camp-on tone to be used at this time, an unmodulated beep
tone having a frequency of 2,000 Hz is generated using an
intermittent pattern of 1-sec ON and 3-sec OFF. FIG. 105C shows the
signal waveform.
[0365] When the called terminal is the standard telephone 4, the
flow advances to step S104i. The RCTU 16 drives the sound source
channel for tone generation which is arranged in the main unit 1.
The time switch section 165 is controlled to connect the sound
source channel to the reception channel of the called standard
telephone 4 intermittently at a predetermined period for extension
call reception. Therefore, the camp-on tone for extension call
reception, which is generated by the main unit 1, is mixed or
inserted into the reception signal and sent to the standard
telephone 4. As the camp-on tone to be used at this time, an
unmodulated beep tone having a frequency of 1,200 Hz is generated
using an intermittent pattern of 160-msec ON and 3-sec OFF. FIG.
105D shows the signal waveform.
[0366] With this arrangement, the DKT user who has received camp-on
notification can identify whether the called line is the extension
line or the office line from the difference between camp-on tones.
On the basis of the identification result, the user can determine
whether he/she should immediately answer the call or may answer the
call after the current extension speech communication is
complete.
[0367] It is determined whether the called terminal is the DKT/EKT
2 or the standard telephone 4, and if the terminal is the DKT/EKT
2, a command is sent from the main unit 1 to cause the DKT/EKT 2 to
generate and output the camp-on tone. If the called terminal is the
standard telephone 4, the camp-on tone is generated in the main
unit 1 and sent to the standard telephone 4, so that the camp-on
tone is output from the standard telephone 4. For this reason, both
the DKT/EKT 2 and the standard telephone 4 can output the camp-on
tone according to the present invention.
[0368] (3-3) Display of Directory Number (DN)
[0369] The digital key telephone system according to the present
invention has a multi DN function. In the multi DN function, a
plurality of directory numbers are set in correspondence with
different DN keys of each digital key telephone, and various
control operations including call sending/reception in the office
line and extension line, various transfer operations such as call
forward (CF), conference speech communication, voice calling (HFU),
message waiting (MW), and call park (CP) are performed using the
directory numbers. The directory numbers are classified into a
primary DN handled as a representative number, a secondary DN
handled as a subordinate number, and a phantom DN handled as a
virtual number. These directory numbers are arbitrarily set in one
digital key telephone.
[0370] Operation examples of use of the DNs in the digital key
telephone DKT will be described.
[0371] 3-31 Extension Speech Communication Using DN Keys
[0372] FIG. 95 is a view for explaining this operation. Assume that
the user of the DKT 200 performs an off-hook operation and
depresses the DN200 key. An LED corresponding to the DN200 key
blinks to display that the DN200 is being used. Upon depressing the
DN200 key, the DKT 200 outputs a dialing tone. When the user who
confirmed the dialing tone dials the extension number of the DKT
201, a call signal is sent from the main unit to the DKT 201. The
called DKT 201 outputs an extension ringing tone, and at the same
time, an LED corresponding to the DN201 key blinks to indicate that
the DKT 201 is being called.
[0373] In this state, the user of the DKT 201 performs the off-hook
operation or depresses the DN201 key, the calling DKT 200 and the
called DKT 201 are connected by the main unit to allow speech
communication between the DKTs 200 and 201. In the speech
communication state, the LED corresponding to the DN201 key of the
called DKT 201 blinks to indicate that the DKT 201 is being used.
When speech communication is ended, and one of the DKTs performs a
speech communication ending operation, the extension lines are
disconnected, and the LEDs of the DKTs 200 and 201 are turned
off.
[0374] 3-32 Setting of CF Destination DN Using Primary DN Key
[0375] FIG. 96 is a view for explaining this operation. When a CF
destination is to be set using the primary DN key, the user of the
DKT 200 of the CF setting source depresses the DN200 key, confirms
the dialing tone, and then dials a CF setting special number
"#601". Next, the user dials the extension number of the DKT 201 as
the CF destination. Finally, the user depresses the RDL key to end
setting. After this, a call received by the DN200 is transferred to
the DN201 by the main unit.
[0376] 3-33 Setting of CF Destination Using Phantom DN Key
[0377] FIG. 97 is a view for explaining this operation. A
description will be made below assuming that the DKT 200 is
registered in advance as the owner terminal of the DN500. To set
the CF destination using the phantom DN key, the user of the DKT
200 of the CF setting source depresses the phantom DN500 key. The
user confirms the dialing tone, dials the CF setting special number
"#601", and then dials, e.g., the extension line, 203, of the DKT
203 as the CF destination. Finally, the user depresses the RDL key
to end CF setting. After this, a call received by the DN500 of the
setting source is transferred to the D 203.
[0378] 3-34 Setting of Voice Mail ID Code Using Primary DN Key
[0379] FIG. 98 is a view for explaining this operation. When a
voice mail ID code is to be set using the primary DN key, the user
of the DKT 200 as the setting source depresses the DN200 key. The
user confirms the dialing tone, dials a special number "#656" for
setting the voice mail ID code, and dials the ID code. The user
finally depresses the RDL key to end voice mail ID code
setting.
[0380] A method of using the voice mail ID code will be described.
The user performs, on the self DKT 200, an operation of setting the
voice mail unit as the CF destination before he/she leaves the
position. After this, a call received by the DKT 200 is transferred
to the voice mail unit by the main unit so that the message from
the calling line is recorded in the voice mail unit. The voice mail
ID code represents an address for recording the message. When the
voice mail unit answers the call, the voice mail ID code is sent
from the main unit to the voice mail unit as a DTMF signal. With
this operation, an address of the voice mail unit is designated to
store the message.
[0381] When the message is recorded in the voice mail unit, the DKT
of the CF source blinks a message lamp to notify the user that the
message is recorded. The message lamp blinks when the voice mail
unit sends a special number for blinking the message lamp to the
DKT.
[0382] In this state, when the user comes back to the position and
depresses the message lamp key, the voice mail unit is called back.
The voice mail unit answers the call back, reproduces the message
from the address represented by the ID code, and sends the message
to the DKT.
[0383] 3-35 Voice Mail ID Code Setting Using Phantom DN Key
[0384] FIG. 99 is a view for explaining the operation. The user
depresses the phantom DN500 key of the DKT 200 of the setting
source. After confirmation of the dialing tone, the user dials #656
or the special number for setting the voice mail ID code and then
dials the ID code corresponding to the phantom DN500. Finally, the
RDL key is depressed. With this operation, voice mail ID code
setting is complete.
[0385] When a call addressed to the DN500 is transferred to the
voice mail unit, the voice mail ID code is sent from the main unit
to the voice mail unit to designate a message storage address.
[0386] 3-36 Display for Confirming DN Number
[0387] In the above-described multi DN function, the user can
arbitrarily set a plurality of DN numbers in correspondence with
the DN keys. Therefore, when the user is to use the key telephone
of the third party, the user does not know the correspondence
between the DN keys and the DN numbers. Even the user
himself/herself may forget the directory numbers set for the DN
keys to hinder call forward setting or the like. In addition, when
the installation operator is to test extension calling in
installing the system, and the DN numbers of the extension lines
are unknown, function setting must be referred to, resulting in a
considerably cumbersome operation.
[0388] In the system of the present invention, when a directory key
of the digital key telephone is depressed, and a predetermined
special number operation is performed, the main unit 1 reads out
the directory numbers set for the DN keys from the memory and
displays them on the LCD 28 of the digital key telephone. FIGS. 38A
to 38C show examples of the operation procedure and contents
displayed on the LCD 28.
[0389] More specifically, to confirm the directory number set for
an arbitrary DN key of the digital key telephone, the object DN key
is depressed first. At this time, "INT" is displayed on the LCD 28
of the telephone, as shown in FIG. 38A. In this state, when a
special number "#401" is input, the directory number corresponding
to the DN key, "DN=210", is displayed on the LCD 28 under the
control of the main unit 1, as shown in FIG. 38B.
[0390] Directory number confirmation is performed in correspondence
with a selected DN key. For this reason, if the special number
operation is performed while the secondary DN key is being
selected, the directory number of the secondary DN key is
displayed. Similarly, if the special number operation is performed
while the phantom DN key is being selected, the directory number of
the phantom DN key is displayed.
[0391] When the special number operation is performed to confirm
the extension number after the DN key operation, the extension
number "INT=210" is displayed, as shown in FIG. 38C. Therefore, the
user can confirm the extension number corresponding to the DN key
from this display.
[0392] FIGS. 39A to 39D show examples of the operation and display
associated with an inquiry. FIGS. 39A, 39B, 39C, and 39D show DN
number confirmation, extension number confirmation, accommodation
position number confirmation, and slot number confirmation,
respectively.
[0393] FIG. 100 is a flow chart showing the procedure and contents
of the above-described DN number display control. When the user
depresses a DN key to be checked, the main unit detects this
operation in step S100a. The flow advances to step S100b to send a
dialing tone to the DKT where the DN key is depressed and also send
a display control signal to blink an LED corresponding to the DN
key. In step S100c, a message for promoting dialing is displayed on
the LCD of the DKT. In step S100d, the DN number of the depressed
DN key is read out from the key arrangement area (RAM)
corresponding to the DKT and writes the DN number in the connection
DN area corresponding to the DKT. FIG. 101 shows an example of this
connection DN area.
[0394] If the key depressed on the DKT is a key other than DN keys,
the flow advances from step S100a to step S100e. The main unit
determines whether the input key is a dial key. If YES in step
S100e, it is determined in steps S100f to S100i whether the input
number is the DN display special number (#407). When it is
confirmed that the input number is the DN display special number,
the connection DN area is searched for, and the DN number
corresponding to the DN key is displayed on the LCD of the DKT.
[0395] In this state, when the user of the DKT performs the on-hook
operation, the flow advances from steps S100e and S100k to step
S100l. The main unit ends display of the DN number on the LCD of
the DKT and restores calendar display. In step S100m, the storage
contents in the connection DN area are cleared. In step S100n, the
LED of the DKT is turned off.
[0396] With this function, it can be easily and reliably confirmed
that the DN key has the primary DN, the secondary DN, or the
phantom DN. Therefore, the user and the wiring installation
operator can easily determine the DN key to be used to set call
forward or the like.
[0397] 3-37 Function Setting for Keys of DKT/EKT
[0398] FIG. 102 is a view showing the setting procedure. By dialing
the special number "*#*#1*2*3" on the DKT as a fixed terminal, the
DKT is set in the function setting mode. When a key operation is
performed in the procedure shown in FIG. 102, the function of each
key is set. The set functions are stored in the key arrangement
area of the RAM. FIG. 103 shows an example of the key arrangement
area.
[0399] (3-4) Storage/Display Control of Call Reception
Information
[0400] In the digital key telephone system according to the present
invention, when one or a plurality of calls are received by a busy
digital key telephone, pieces of call reception information
associated with the received calls are stored in the main unit 1.
In this state, when a request for knowing the contents of the
received calls is sent from the busy digital key telephone or a
personal computer connected to the telephone, the pieces of stored
call reception information are sent from the main unit 1 to the
digital key telephone or the calling line identification
information of the request source and displayed.
[0401] FIGS. 40A and 40B are flow charts showing the procedure of
call reception information storage and display control. The main
unit 1 monitors arrival of a call from the office line in step
S40a. In this state, when a call arrives, it is determined in step
S40b whether the called digital key telephone 2 is available. If
YES in step S40b, the call is received by the digital key telephone
2, and call reception information is transmitted to the personal
computer 3 and displayed. In step S40j, it is determined whether
the telephone 2 answers the call. If YES in step S40j, control is
ended without storing the call reception information. If NO in step
S40j, the flow advances to step S40d to store the call reception in
the call reception answering area in correspondence with the called
office line number. This call reception information area is
provided in units of digital key telephones 2.
[0402] If the called digital key telephone 2 is busy, the flow
advances from step S40b to step S40d to store the call reception in
the call reception information area in correspondence with the
called office line number.
[0403] In this state, assume that the user performs a command input
operation on the personal computer 3 corresponding to the self
digital key telephone 2 to know the contents of calls addressed to
the user. The command is sent from the personal computer 3 to the
main unit 1. When the command is received, the flow advances from
step S40e to step S40f. The main unit 1 checks the corresponding
call reception information area. In step S40g, it is determined
whether the called office line numbers in waiting for call
reception are stored. If YES in step S40g, one of the office line
numbers is selected in step S40h to read out the corresponding call
reception information and send it to the personal computer of the
request source. The call reception information is displayed on the
display of the personal computer 3.
[0404] If NO in step S40g, the flow advances to step S40i to
determine whether all areas are checked. If unchecked areas remain,
the flow returns to step S40f to check the next area, and call
reception information sending and display control is repeated.
[0405] With this operation, pieces of call reception information
addressed to the user are sequentially displayed on the personal
computer 3. Therefore, even in the busy state, the user can confirm
all pieces of information of calls addressed to the user and
waiting for reception on the personal computer 3. An important call
can be selected from the calls waiting for reception after the end
of speech communication, so the user can answer the call.
[0406] In the above description, when a plurality of pieces of call
reception information are stored in the call reception information
area, the call reception information area is checked by every
scroll operation on the personal computer 3. The pieces of call
reception information are read out one by one, sent to the personal
computer 3 of the request source, and displayed on the display of
the personal computer 3. However, the present invention is not
limited to this. For example, the plurality of pieces of call
reception information may be read out at once in accordance with
the request from the personal computer 3, sent to the personal
computer 3, and listed on the display of the personal computer
3.
[0407] In addition, in the above description, when the user
performs a call reception information display request operation on
the personal computer 3, the call reception information area is
checked to send the call reception information to the personal
computer 3 and display it. The display request command may be sent
from the personal computer 3 in the busy state once automatically
or periodically, and the main unit 1 may check the call reception
information area accordingly to send the stored call reception
information to the personal computer 3 and display it.
Alternatively, even time a new call arrives in the busy state, the
main unit 1 may send the call reception information to the personal
computer 3 to display it.
[0408] (3-5) Control Associated with Call Park
[0409] In call park, when an extension terminal answers an incoming
call and performs a predetermined operation of requesting call
park, the call is held at a virtual holding position called a park
zone. In this state, when a special number operation of answering
the call is performed by another extension terminal, the extension
terminal can reanswer the call.
[0410] Assume that an extension terminal a answers a call to be
received by an extension terminal g. When the user of the extension
terminal a performs a special number operation, the call is parked
in the park zone. In this state, the user of the extension terminal
a calls the extension terminal g by broadcasting and requests the
user of the extension terminal g to answer the parked call. When
the user of the extension terminal g performs a predetermined park
answering operation in accordance with the request, the extension
terminal g and the held call are connected to allow the user of the
extension terminal g to answer the call.
[0411] The call is parked in the park zone in correspondence with
information representing a park address called an orbit number.
Conventionally, different orbit numbers are used to park a call for
the first time and repark the same call. For this reason, when the
called party does not answer the parked call, and the call is
reparked, the same call is undesirably parked in correspondence
with different orbit numbers.
[0412] To prevent this, in the digital key telephone system of the
present invention, when a call to be subjected to call park is
parked in correspondence with an orbit number, the orbit number is
held until the end of the speech communication of the call. When a
call park request for the call is generated again during speech
communication of the call, the call is parked in correspondence
with the held orbit number.
[0413] FIG. 41 shows an example of a park reservation table used
for call park, which is arranged in the memory in the RCTU 16. This
park reservation table has n park areas with orbit numbers #1 to
#n. The numbers of office line trunks which have received calls to
be parked and the number of terminals which have sent call park
requests are stored in these park areas.
[0414] FIG. 42 is a flow chart showing the procedure of call park
control by the RCTU 16. In step S42a, the RCTU 16 monitors whether
the park key of the called extension terminal is depressed during
office line call reception. In this state, when the park key of the
extension terminal is depressed, the RCTU 16 determines in step
S42b whether the park reservation table has an available park area,
i.e., an available orbit. If YES in step S42b, the flow advances to
step S42c to perform the park operation.
[0415] In step S42d, the number of the trunk which has received the
call and the number of the extension terminal which has sent the
park request are stored in one of available orbits. Assume that
extension terminal "005" has sent a park request for a call
received by office line trunk "001", and orbit #1 is available. In
this case, as shown in FIG. 41, the trunk number "001" and the
extension terminal number "005" are stored in orbit #1. The RCTU 16
stores orbit number #1 as a reservation orbit corresponding to the
call until the speech communication of the call is ended.
[0416] If NO in step S42b, park is disabled in step S42e.
[0417] Assume that the called party does not answer the parked
call, and the user of the extension terminal depressed the call
park key again to call another extension terminal. The RCTU 16
executes park control again. FIG. 43 is a flow chart showing the
control procedure. When the call park operation is detected, the
flow advances from step S43a to step S43b, and the RCTU 16
determines whether the reservation orbit is present. If YES in step
S43b, the flow advances to step S43c to store the number of the
trunk which has received the parked call and the number of the
extension terminal which has sent the call park request again in
correspondence with the reservation orbit.
[0418] If the call park request is sent, and no reservation orbit
is stored, the flow advances to step S43d to disable park.
[0419] Assume that the called party answers the call in park or
repark. In this case, the RCTU 16 executes pickup control in the
following manner. FIG. 44 is a flow chart showing the control
procedure. When a pickup operation for the parked call is detected,
the flow advances from step S44a to step S44b. The RCTU 16 accesses
the reservation orbit of the park reservation table to determine
whether the call is parked. If YES in step S44b, the flow advances
to step S44d to perform pickup control. More specifically, the
extension terminal which has answered is connected to the trunk
which has received the parked call to allow speech communication.
If NO in step S44b, information stored in the corresponding orbit
of the park reservation table is deleted.
[0420] In the system with the above arrangement, when the repark
operation is performed, the call to be subjected to call park is
parked in correspondence with the same orbit number as that in the
preceding call park. For this reason, the call is prevented from
being parked in correspondence with different orbit numbers.
[0421] (3-6) Control for Mode Change Request from
[0422] Personal Computer In the system according to the present
invention, an operation mode change request sent from the personal
computer 3 is transferred to the main unit 1 through the personal
computer interface unit (PCI-DI) 2b of the DKT/EKT 2. When the mode
change request is transferred, the main unit 1 determines whether
the mode change request is appropriate and notifies the PCI-DI 2b
of the mode change request transfer source of the determination
result. The PCI-DI 2b performs mode change processing according to
the mode change request of the personal computer on the basis of
the notified determination result.
[0423] FIG. 45 is a flow chart showing the procedure and contents
of mode change control in the PCI-DI 2b and the RCTU 16 of the main
unit 1.
[0424] When a mode change command is input from the personal
computer 3, the flow advances from step S45a to step S45b. The
PCI-DI 2b transfers the mode change command to the main unit 1. The
RCTU 16 of the main unit 1 monitors arrival of the mode change
command from the PCI-DI 2b in step S45g. When the mode change
command arrives, the flow advances to step S45h to analyze the
contents of the mode change command. In step S45i, it is determined
whether the mode change requested by the mode change command is
allowed. If YES in step S45i, the mode change command is returned
in step S45j. If NO in step S45i, the flow advances to step S45k to
return a mode change rejection command to the PCI-DI 2b.
[0425] After sending the mode change command, the PCI-DI 2b
monitors return of the mode change command and the mode change
rejection command from the main unit 1 in steps S45c and S45e. In
this state, when the mode change command is returned from the main
unit 1, the flow advances to step S45d to execute mode change
processing. This mode change processing is performed by the data
communication control microcomputer 245.
[0426] The PCI-DI 2b supplies a mode change enable signal to the
personal computer 3 and at the same time sets the PCI-DI 2b itself
in an operation state corresponding to the changed mode, i.e., a
state wherein the extension line is connected to the personal
computer. On the other hand, when the mode change rejection command
is returned from the main unit 1, the flow advances to step S45f,
and the PCI-DI 2b executes mode change inhibition processing. More
specifically, the PCI-DI 2b notifies the personal computer 3 of
mode change inhibition, and simultaneously, sets the self operation
state such that even when an operation corresponding to the changed
mode is performed by the personal computer 3, the signal is not
transferred to the main unit 1.
[0427] As described above, in this system, when the mode change
request is issued from the personal computer 3, the RCTU 16 of the
main unit 1 always determines whether the request is appropriate.
Only when it is determined that the request is appropriate, the
PCI-DI 2b is allowed to change the mode. Therefore, a mode which is
not prepared for the main unit 1 can be prevented from being set in
the PCI-DI 2b.
[0428] For example, assume that the user sends a request for
changing the mode to a computer telephoni mode for calling using
the personal computer 3. However, when the main unit 1 does not
have the computer telephoni mode, the main unit 1 does not return
mode change enable notification. For this reason, the computer
telephoni mode is not set in the PCI-DI 2b.
[0429] (3-7) Display Control for Held Line
[0430] When a certain digital key telephone 2 holds an office line
or an extension line, the number of the held office line or
extension line is displayed on the LCD 28 of the digital key
telephone 2. However, if a plurality of office lines or extension
lines are held, the user cannot determine the correspondence
between the office lines or extension lines which are displayed in
holding and the flexible buttons.
[0431] In the digital key telephone system according to the present
invention, when a plurality of office lines or extension lines are
held, and a holding information display operation is performed on
the digital key telephone, the numbers of the plurality of held
office lines or extension lines are selectively displayed on the
LCD of the digital key telephone in accordance with the display
operation. In addition, the LEDs of the flexible buttons
corresponding to the held office lines or extension lines are,
e.g., blinked synchronized with the LCD display operation.
[0432] FIG. 46 is a flow chart showing the holding display control
procedure. In the following description, assume that office lines
correspond to 10 flexible buttons 24, and these flexible buttons
are used as line selection keys.
[0433] In step S46a, the RCTU 16 of the main unit 1 monitors
whether a scroll key 29 of each digital key telephone 2 in the
standby state is depressed. When the scroll key 29 of an arbitrary
digital key telephone 2 is depressed, the count value is set at 1
in step S46b. The flow advances to step S46c to search the holding
information area for an area corresponding to the count value=1.
The holding information area is arranged in the memory of the RCTU
16 in correspondence with each digital key telephone. As shown in
FIG. 47, the holding information area stores the held office line
numbers in correspondence with the line selection keys.
[0434] In step S46d, the RCTU 16 determines on the basis of the
search result obtained in step S46c whether the held line number is
stored in correspondence with the first line selection key number.
If the held line number is not stored as in FIG. 47, the flow
advances to step S46g without performing held line number display
control. The count value is incremented by one. In step S46h, it is
determined whether holding display control is performed for all of
the 10 line selection keys. In this case, since line selection keys
which have not undergone display control remain, the flow returns
to step S46c to search for holding information area corresponding
to the second line selection key number. It is determined in step
S46d whether the held line number is stored in correspondence with
the second line selection key number. If the held line number is
stored as shown in FIG. 47, the held line number is read out,
transferred to the digital key telephone 2, and displayed on the
LCD 28 in step S46e. Simultaneously, an LED control signal is sent
to the digital key telephone 2 to blink the LED 25 corresponding to
the first line selection key where the held line number is stored.
The blinking frequency is set at, e.g., 10 Hz as a natural
frequency to allow discrimination from another blinking
display.
[0435] When the held line number is displayed on the LCD 28, and
the LED 25 is turned on, the flow advances to step S46g. The RCTU
16 increments the count value by one. In step S46h, it is
determined whether display and ON-control are performed for all of
the 10 line selection keys. If NO in step S46h, the flow returns to
step S46c to repeat the above control.
[0436] As described above, in this system, when the held line
number display operation is performed, the held line number is
displayed on the LCD 28, and the LED 25 of the line selection key
corresponding to the held line blinks. Therefore, even when a
plurality of lines are held, the user can clearly know the
correlation between the held line numbers which are being displayed
on the LCD 28 and the line selection keys.
[0437] FIG. 48 shows an order of blinking the LEDs 25 corresponding
to line selection keys 24.
[0438] In the above description, the RCTU 16 of the main unit 1
performs holding display control. However, the microcomputer of
each digital key telephone 2 may perform the control. In the above
description, the LEDs 25 corresponding to the line selection keys
are blinked. However, line selection key numbers may be displayed
on the LCD 28 together with the corresponding held line numbers. In
addition, holding information to be displayed on the LCD 28 is not
limited to the held line number. A caller ID, a directory number,
or a user name may be displayed. Furthermore, holding display
control for each line selection key may be performed by
sequentially selecting a line selection key every time the scroll
key 29 is depressed.
[0439] (4) Multi DN Function
[0440] In the multi DN function, as described above, a plurality of
directory numbers are set in correspondence with different flexible
buttons in each digital key telephone (DKT), and various control
operations such as call sending/reception from/to the office line
or extension line, various transfer operations such as call
forward, conference speech communication, message waiting, or call
park are performed using the buttons as DN keys.
[0441] (4-1) Arrangement of DN Keys
[0442] As a DN key arrangement, a single DN key is set for a
plurality of DKTs, or a plurality of identical DN keys are set on
one DKT. Alternatively, a phantom DN key is set in addition to the
primary DN key and secondary DN key. FIG. 49 shows an example of
the DN key arrangement, in which "501", "500", "200", "201", and
"202" are arbitrarily set for DKT #200, DKT #201, and DKT #202.
[0443] (4-2) General Description of Various Operations Using
DNs
[0444] Operations using the DN keys will be briefly described
below. FIGS. 50 to 56 are views for explaining the operations.
Symbols in FIGS. 50 to 56 represent LED display patterns
corresponding to the DN keys and have meanings defined in FIG.
94.
[0445] FIGS. 50 and 51 show an operation in which voice-calling
(HFU) or tone calling is performed, and the called side answers the
call, an operation in which calling by CONF is performed, and the
called side answers the call, an operation of performing conference
by reCONF, and an extension transfer operation.
[0446] FIG. 52 shows an extension ring transfer (extension line
R.T) operation, including an operation of R.T call back to the
transfer side at the R.T timeout.
[0447] FIG. 53 shows an ACB (Automatic Call Back) operation. In
this operation, DKT #200 sets ACB during speech communication of
DKT #202, ACB is performed after speech communication of DKT #202,
and DKTs #200 and #202 answer the call to allow speech
communication between the DKTs.
[0448] FIG. 54 shows office line calling and ring transfer
operation using a DN. FIGS. 55 and 56 show an office line calling
and conference operation using a DN.
[0449] (4-3) Extension Calling Using DN Keys
[0450] Like the conventional use of INT keys, extension calling can
be performed by an available DN key operation. This also applies to
use of the primary DN, the secondary DN, or the phantom DN.
[0451] In on-hook calling or SPKR (Speaker Key) calling in the
available state, when the automatic calling selection function is
set to allow extension calling, and there is a DN key which can
send a call, DN calling can be performed by selecting the primary
DNs in ascending order of numbers. If all DNs are not available,
calling cannot be performed. For an SLT (Single Line Telephone),
when the secondary DN is set for the DKT, the SLT cannot perform
calling, though the DN of the SLT can be set for other extension
lines.
[0452] To send a call by depressing another DN key during speech
communication, the speech communication is ended, and an available
DN key is depressed to allow extension calling. Even when a DN key
which is being used for speech communication is depressed during
the speech communication, the speech communication is ended
independently of whether it is office line or extension speech
communication, and new extension speech communication is
performed.
[0453] (4-4) Extension Operation
[0454] 4-4-1. In independent extension calling, HFU (Hands Free
Unit) calling is used to call only one called DKT of the primary
DNs. When a phantom DN is called by HFU calling, the owner terminal
is called. In tone calling, only the primary DN or also the
secondary DN are called depending on setting. Delay call reception
is also enabled by setting. HFU calling or OCA calling to the
phantom DN cannot be performed. Other operations are the same as
those for the secondary DN.
[0455] 4-4-2.Independent calling in one voice direction is
processed as in HFU calling.
[0456] 4-4-3. In tone calling, even when calling is set, and if
calling cannot be performed because of the busy state of the
terminal, BOV (Busy Override) is displayed on the LED of the DN
upon call reception, as needed.
[0457] 4-4-4. LED Display of Extension Call Reception
[0458] In LED display of extension call reception, when a plurality
of calls are received by longitudinal multiple DNs, "I-Called" is
displayed at the key of primary call reception to specify the DN
which outputs the ringing tone. FIG. 57 shows an example of LED
display of DN keys.
[0459] 4-4-5. Even when all DKTs from which the ringing tone is to
be generated are not available, and no ringing tone can be
generated, a ring-back tone (RBT) is returned to the calling
terminal as far as a DN is available. However, when all terminals
from which the ringing tone is to be generated are in the DND
(DoN't Disturb) state, the RBT is returned to the calling
terminal.
[0460] 4-4-6. No Available DN or No DN Key
[0461] When all primary DN keys set on a certain terminal are not
available, all of the DNs are not available. For example, when
three primary DN keys are set on a certain terminal, and all of the
three primary DN keys are not available, no DN is available. When
the DN number called is not available, and extension calling is
generated, this call temporarily becomes busy. A camp-on tone is
sent by the operation of the calling line to want for an available
DN key. Even when the primary DKT is available, the busy state is
set. Even when the DKT called by HFU calling has no primary DN
keys, the busy state is set. This is a problem to determine how to
perform LED display upon answering or how to allow a third party to
answer when the call is answered and held.
[0462] FIG. 58 is a table showing an operation when no DN is
available or no DN key is available. The camp-on tone when no DN is
available is sent to a terminal which is using the called DN and
has tone calling call reception setting independently of whether
calling is performed as voice calling or tone calling.
[0463] 4-4-7. Processing of Extension Call Reception During
Extension Call Reception
[0464] A call arriving during extension call reception is received
only when a DN is available. The first call reception has a
priority, and the second call reception is subjected only to LED
display, and no ringing tone is output. HFU calling during
extension calling is temporarily set in the busy state and then
processed as tone calling by the subsequent operation. When the
second call is a call by HFU calling, and the first call reception
is stopped, the call is restored as tone calling. This is because
the calling line is prevented from being confused when the RBT
abruptly changes to voice calling. FIG. 59 is a table showing the
above processing of extension call reception during extension call
reception.
[0465] 4-4-8. Group calling and broadcasting are performed by
function setting corresponding to ports. At this time, LED display
of the DN key is not performed on the called side.
[0466] 4-4-9. Switching from tone calling to voice calling is
neglected when the DKT having the primary DN is busy or absent.
When voice calling is switched to tone calling, a delay ring
operation is performed.
[0467] 4-4-10. Busy Override and OCA (Off-hook Call Announce)
[0468] When the called terminal is performing handset speech
communication, and HFU calling is generated, a BT (Busy Tone) state
is set independently of the presence/absence of an available DN.
However, if OCA has been set, the terminal is set in the OCA state
by the operation of the calling line. In the system of the present
invention, the OCA call reception is not displayed on the LED of
the DN key. OCA continues even when the connected line is released
(held or disconnected).
[0469] The OCA state can be directly set without intervening the BT
state by wiring installation of automatic OCA.
[0470] Assume that a DN is available. In this state, when tone
calling is generated, and a connected line is present, the terminal
is automatically set in the BOV state. When the connected line is
released (held or disconnected), the BOV stops, and tone calling is
restored. In HFU calling, even when the called terminal is busy,
the BOV state is set as far as the called terminal has wiring
installation of HFU calling automatic BOV. When the called terminal
is in the DND state, and HFU calling is busy, processing according
to the DND override wiring installation of the calling line is
performed.
[0471] 4-4-11. When a call reception calling set DKT returns from
the nonavailable state to the available state, OCA calling is
continued although BOV is switched to tone calling. That is, the
call is restored.
[0472] b 4-4-12. ACB
[0473] ACB can be performed by an operation when no DN is available
or after a busy terminal returns a busy tone. ACB occurs when both
the DN called by ACB and the called DN are available, and both the
calling and called terminals are available.
[0474] 4-4-13. DND
[0475] The relationship between extension call reception by voice
or tone calling and DND is changed by the multi DN function. Tone
calling or office line call reception is not performed in the DND
state. Voice calling to a terminal in the DND state is temporarily
set in the SBT (Special Busy Tone) state and then in the BOV
calling or OCA state by the operation of the calling line. FIG. 60
shows an example of DND processing during call reception.
[0476] When a DN key as a secondary key does not answer a call of
tone calling, i.e., lateral single appearance occurs, and the
called terminal is in the DND state, the SBT is output. When a DN
as a secondary DN answers the call, i.e., lateral multi appearance
occurs, the SBT is returned to the calling line even when all
terminals are set in the DND state. Once tone calling is performed,
the calling line is not set in the BT state even when all called
terminals are in the DND state. DND override by the user operation
after the calling line listens to the SBT is performed according to
the wiring installation of the calling line. At this time, BOV call
reception is performed by all the DND terminals. A terminal which
has canceled DND is called by tone calling. DID (Direct-Inward
Dialing) or leased line call reception is also set in the DND busy
state, like tone calling. However, not the SBT but the BT is
output, and the call is blocked.
[0477] 4-4-14. Call Forward (CF)
[0478] Call forward is performed in accordance with CF setting at
the primary DN. CF-BUSY is determined when no terminal or DN is
available for HFU calling and all DNs are not available for tone
calling. When no answer is obtained as a result, call forward is
performed. CF can also be set for the phantom DN. In this case, a
call addressed to the phantom DN is subjected to call forward. FIG.
61 shows the call forward operation.
[0479] Even when the phantom DN is set as the CF destination, voice
calling can be performed, like the primary DN. FIG. 62 is a view
showing the operation.
[0480] CF Setting
[0481] CF setting for the primary DN and CF setting for the phantom
DN are performed in the following manner.
[0482] "[P DN]+#601, 2, 3, 4, +CF destination [+NA timer]#"
[0483] "[PH DN]+#601, 2, 3, 4, +CF destination [+NA timer]#"
[0484] CF setting for the phantom DN can be performed only from the
owner of the phantom DN.
[0485] The CF destination for the primary DN can also be set for
the phantom DN. Setting from the phantom DN to the primary DN or
another phantom DN can also be performed.
[0486] Confirmation of CF Setting by LCD
[0487] A terminal as the owner of the phantom DN can set a
plurality of CF destinations. In this case, to confirm CF setting,
the LCD display of CF destinations is scrolled using the scroll
key. FIG. 63 shows a display example.
[0488] FCF (Fixed CF)
[0489] In FCF, a call addressed to the primary DN is subjected to
CF.
[0490] CF Key (LED)
[0491] The LED of the CF key indicates the CF state of the primary
DN and does not display setting for the phantom DN.
[0492] 4-4-15. Station Hunting (SH)
[0493] The SH busy is determined when no terminal or DN is
available for HFU calling and all DNs are not available for tone
calling. Not only SH from the primary DN to the phantom DN but also
SH from the primary DN to the phantom DN and vice versa, or from
the phantom DN to another phantom DN can also be performed.
[0494] 4-4-16. Message Waiting (MW)
[0495] MW is received by a called primary terminal. MW to a phantom
DN is received by the owner of the phantom DN. At this time, the MW
is displayed on the phantom MW key. If there is no MW key, the MW
cannot be received.
[0496] FIG. 64 shows the correlation between phantom DNs and MW
keys. As shown in FIG. 64, the correlation between each phantom DN
and a phantom message waiting key (ph-MW key) is determined in
advance. Four MWs can be set for each phantom DN. Only the owner
terminal can have the ph-MW keys. The ph-MW key is used for display
of MW reception and call back. To set MW, the MW key is used.
[0497] LCD Display of MW
[0498] In MW reception, the DN number and terminal number which
have received the MW are simultaneously displayed on the LCD 28 by
operating the scroll key 29. FIG. 65 shows a display example. In
FIG. 65, "XXXX" represents a DN number which has received the MW,
and "YYYY" represents the telephone number of a terminal for which
MW is set.
[0499] In ME transmission, the DN number for which MW is set is
sequentially displayed by operating the scroll key 29, as shown in
FIG. 66. In FIG. 66, "xxxx", "YYYY", and "ZZZZ" represent DN
numbers for which MW is set.
[0500] NW Call Back Operation by MW Key
[0501] By depressing a blinking MW key, the primary DN can be
captured, and the terminal for which MW is set can be called back.
The ph-MW key is used to capture the phantom DN to send a call. The
MW can also be set using the secondary DN. In this case as well,
the primary DN of the terminal for which MW is set is called back.
In MW reception by the phantom DN as well, the primary DN of the
terminal for which MW is set is called by depressing the ph-MW
key.
[0502] MW Reception Operation
[0503] MW reception by the primary DN is performed as shown in FIG.
67. MW reception by the phantom DN is performed as shown in FIG. 68
or 69.
[0504] MW Transmission Operation
[0505] MW transmission from the primary DN is performed as shown in
FIG. 70. MW transmission from the secondary DN is performed as
shown in FIG. 71. MW transmission from the phantom DN is performed
as shown in FIG. 72.
[0506] 4-4-17. DSS (Direct Station Selection) and BLF (Busy Lamp
Field)
[0507] A DSS call is used to call not a terminal but a DN. When the
DSS key of an idling terminal is depressed, the primary DN is
captured to call the DN of the other party. BLF display of ATT,
DSS, ADM, and LCD indicates not the DN state but the terminal
state. Therefore, in the BLF, a DSS call may be set in the BT state
when no DN is available but the terminal is available.
[0508] 4-4-18. Answer to Extension Call Reception
[0509] An extension call reception displayed on the DN key can be
answered by depressing the DN key. Even when another DN key of the
same DN number is depressed, the call cannot be answered. In
off-hook or SPKR operation in the automatic call reception
selection mode as well, the call is answered by the DN with call
reception display.
[0510] 4-4-19. Pickup Answering
[0511] Pickup answering can be performed by depressing a DN key
with call reception display. LED display at this time is similar to
that of the pickup special number. Pickup using the pickup special
number can also be performed by waiting for a dialing tone from
another DN key. To designate a called extension number, not the DN
but the called terminal is designated.
[0512] 4-4-20. Privacy During Extension Speech Communication
[0513] Only one terminal is connected to a DN of one type (e.g.,
DN200-1). Privacy cancel or privacy override by the DN is not
permitted.
[0514] 4-4-21. ID Sending to Voice Mail
[0515] When the CF destination is a voice mail or MW from a voice
mail is called back, and ID sending has been set, an ID is sent.
Not only the ID of the primary DN but also that of the phantom DN
is sent. At this time, the IDs of the primary DN and the phantom DN
are discriminated. ID setting for the phantom DN is performed by
the owner DKT of the DN. FIGS. 73 and 74 are views showing
operations of sending the ID to a voice mail for MW and CF,
respectively.
[0516] 4-4-22. LCD Messaging
[0517] In tone calling, extension call reception display is
performed on (one or a plurality of) terminals capable of receiving
a call. When the calling line is calling from a phantom DN, the
terminal number is displayed as the calling line number. This also
applies to a secondary DN. When a person other than the called
party answers voice or tone calling, display similar to that in
pickup is performed.
[0518] To start character communication, the busy called party
depressed "MODE key+2" when the calling line sends an extension
call. In the multi DN, character communication is performed when no
DNs are available, the other party is busy or receiving a call in
HFU calling, and the call by HFU calling is rejected due to
DND.
[0519] The LCD can display character communication by the phantom
DN, a silent message, or a message for absence answering. For a
phantom DN, no unique message is used, and the message of the owner
terminal is shared.
[0520] 4-4-23. Buzz (Buzz Tone) Key
[0521] When a Buzz key on a terminal is depressed, a terminal as a
destination of the contents of the abbreviated dial corresponding
to the Buzz key is called by the Buzz tone and LED. Up to four Buzz
keys can be set for one terminal. For example, the Buzz key is used
by, e.g., a pair of a boss and a secretary.
[0522] By blinking the LED for 0.5 sec, the reception of the
operation is notified to the Buzz key operator. On the called
terminal, a Buzz tone is generated, and the LED is turned on for 4
sec to notify the reception. When a plurality of Buzz keys are set
on one terminal, the Buzz key operator cannot be determined from
the tone. However, the called party checks the LED to identify the
Buzz key operator. FIG. 75 shows the operation. FIG. 76 shows the
ON timing of the LED of the Buzz key operation terminal, the ON
timing of the LED of the Buzz called terminal, and the MSG tone
generation pattern.
[0523] When the Buzz called terminal is available, the MSG tone is
generated in a pattern of 1-sec ON, 0.5-sec OFF, and 1-sec ON. When
the called terminal is not available, a beep tone (10 Hz) is
generated in a pattern of 1-sec ON, 0.5-sec OFF, and 1-sec ON. The
Buzz tone overrides DND and is not influenced even when no DN is
available.
[0524] 4-4-24. Camp-on Tone Sending to Single Line Telephone
[0525] When a call arrives at a busy SLT, the call is subjected to
camp-on. In the SLT, the camp-on tone is sent as 2 Beep (not a Beep
tone in fact) from the handset. Therefore, the speech communication
instantaneously stops during the camp-on tone sending period,
though it is a minimum time and does not influence on the speech
communication. The camp-on tone can be changed between extension
call reception and office line call reception. For example, as an
extension call reception camp-on tone (including leased line ring
transfer and extension ring transfer), a message recording box tone
(1,209 Hz) intermittently output in a repeated pattern of 1-sec ON,
3-sec OFF, and 1-sec ON is used. As an office line call reception
camp-on tone (including DID and office line ring transfer), a
message BOX tone (1,209 Hz) modulated at 10 Hz intermittently
output in a repeated pattern of 1-sec ON, 3-sec OFf, and 1-sec ON
is used.
[0526] (4-5) Extension Transfer
[0527] 4-5-1. Extension Ring Transfer
[0528] This system allows extension ring transfer. However, when
the terminal which has performed ring transfer (RT) ends speech
communication after "CONF (Conference) +dial", the calling DN
becomes available. Call back to RT is addressed to the DN which has
performed RT. In ring transfer, when the DNs of the other party are
not available, camp-on is performed. The camp-on tone is sent to a
terminal which is using the called DN and having extension call
reception setting. Extension RT call reception to a busy terminal
is BOV call reception. LED display of the multi DNs is "I-Called".
Ring transfer is also delay-received. Details of the operation are
the same as in office line ring transfer.
[0529] 4-5-2. Privacy cancel or privacy override by the DN key is
not performed in extension speech communication/conference.
[0530] 4-5-3. In extension calling busy, when dial key 3 is
depressed, privacy override is performed. For a DKT having the
called primary DN, privacy override is performed for the like used
by the terminal.
[0531] (4-6) Office Line Calling
[0532] 4-6-1. An operation of "DN key+dial key 9" allows office
line calling. As a result, the office line can be accessed. When
the DKT has the office line key, the DN is made available, and
display is shifted to the office line key.
[0533] 4-6-2. Assume that office line calling is to be performed in
the automatic calling selection mode. In this case, when the office
line key of the called office line is not provided, and an access
without intervening the DN key is performed, it is displayed on the
primary DN key. If the primary DN is not available, calling is
disabled.
[0534] 4-6-3. Dial Operation on DN Key
[0535] Redialing, save dialing, trunk queuing, and ABR can be
performed. Calling regulation (dial regulation) and LCR depend on
the operated DKT, i.e., independently of the DN. Memory dialing
allows to set the primary DN in a memory dial.
[0536] 4-6-4. Office Line LED Display
[0537] No problem is posed for display of only the DN key, the
office line key, or the POOL key. When these keys are to be
simultaneously displayed, conventionally, the display of the
calling operation or the like using the dial key 9 is shifted to
the office line side as follows.
"INT LED.fwdarw.CO LED (POOL LED)"
[0538] In this system, the display is shifted as follows.
"IDN LED.fwdarw.CO LED (POOL LED)"
[0539] If the calling DKT has both the CO key and the DN key and
sends a call using the dial key 9 by capturing the DN (even when
holding transfer to the DKT having another DN key is desired
later), the CO is displayed to make the DN available to prevent DN
busy. Transfer to the DKT having the DN key can be performed by the
transfer sequence of "CONF+DN".
[0540] Once "I-Use" is displayed by the DN key, the CO is displayed
on the DN key from the end of transfer to the end of speech
communication. FIG. 77 shows examples of the above-described office
line LED display.
[0541] 4-6-5. Trunk Queuing
[0542] The call back condition changes depending on the
presence/absence of the CO key. When the CO key is present, the CO
is available, and the DKT which has set trunk queuing is idle,
trunk queuing occurs. To the contrary, when the CO key is not
present, the CO is available, the DKT which has set trunk queuing
is idle, and the DN used to set trunk queuing is available, trunk
queuing occurs.
[0543] (4-7) Office Line Call Reception
[0544] 4-7-1. Generation of a ringing tone is controlled by office
line setting and the presence/absence of the DN keys. Even with
call reception setting, the ringing tone is not generated when no
DN keys are set.
[0545] 4-7-2. LED Display of Call Reception
[0546] When a plurality of calls are received by vertical multi
DNs, "I-Called" is displayed on the key of primary call reception
to identify the DN key where the ringing tone is generated. FIG. 78
shows the LED display of the CO key, i.e., the display operation
pattern for displaying "I-Called" for the primary line. FIG. 79
shows the LED display of the DN key, i.e., the display operation
pattern for displaying call reception on a designated DN
independently of the presence/absence of the CO key by setting when
a call is received. In this case, if the DNs are not available, no
call reception display is performed.
[0547] 4-7-3. Office Line BOV
[0548] When an office line call is received by an available CO or
available DN of a BUSY terminal, the call reception is displayed on
the LED as in the normal state, and at the same time, the BOV tone
is output. When the call cannot be received by any CO or DN
although call reception setting is made, no BOV tone is generated.
As the BOV tone, 2 Beep or continuous tone can be set in units of
terminals by wiring installation. As the office line BOV tone, the
beep tone of the terminal is modulated at 10 Hz and used. The 2
Beep is generated by sending this tone in a pattern of 1-sec ON,
3-sec OFF, and 1-sec ON while being intermitted only once. The
continuous Beep is generated by sending this tone in a pattern of
1-sec ON, 3-sec OFF, and 1-sec ON while being repeatedly
intermitted.
[0549] 4-7-4. Camp-on of Office Line Call Reception
[0550] When an office line call is to be received by the DN, and
the call cannot be received by the DN because no DN is available,
the call can wait in camp-on. The camp-on tone is sent to the user
of the DN (LED=I-USE) and the terminal having office line call
reception setting. The 2 Beep is used as the camp-on tone, and the
tone is changed to discriminate extension call reception from
office line call reception, as described above.
[0551] 4-7-5. Answer
[0552] The office line call can be answered by CO key pickup, DN
key pickup, the "DN+special number" operation, or the pickup key
operation for CO call reception. If a CO LED is present, "I-USE" is
displayed. At this time, the DN LED is turned off.
[0553] 4-7-6. When the DKT has no CO key or POOL key but a DN key,
DN display is performed only for access through the DN. If the call
is answered using the CO pickup key, display is made on the primary
DN. When the primary DN is not available, the CO pickup key does
not operate.
[0554] 4-7-7. To designate the extension number of the called
terminal using the pickup special number, not the DN but the DKT is
designated.
[0555] (4-8) Call Reception by Leased Line
[0556] When a call is received by a DID or a leased line, LED
display is performed on both the CO key and the DN key, like the
office line call. When the DKT has both the keys, "I-USE" is
preferentially displayed for the CO key. Conventionally, a call to
be received by the DID or the leased line is received by the
extension number. With the multi DN function, the call is received
by the DN in accordance with the extension call reception setting.
Therefore, as far as the called trunk is available, the RBT is
returned to the calling line even though the called DN is not
available except that DND is set for the called terminal as a
whole. If DND is set for the called terminal as a whole, the BT is
returned to the calling line.
[0557] When a call is received by the DID or the leased line when
no DN is available, 1-Hz display is made for the CO key, and in
this state, it is monitored whether the called DN is available. At
this time, the RBT is returned to the calling line. If the called
DN is being used (I-USE), the camp-on tone is sent to a terminal
with extension call reception setting. When the DN becomes
available, the DN is called. FIG. 80 shows an operation in the busy
state.
[0558] (4-9) Office Line Holding
[0559] 4-9-1. When "I-USE" is displayed for the DN key, the call
can be held by depressing the HOLD key independently of whether the
call is an office line call or an extension call. At this time,
"I-USE" changes to "I-HOLD". "I-USE" is kept displayed for the DN
key. Exclusive holding by "HOLD+HOLD" can also be performed.
[0560] 4-9-2. Holding pickup can be performed by depressing the DN
key which is displaying holding. By the conventional "INT+pickup
special number+extension number" operation, the held terminal is
designated, as in call reception. DN designation during holding is
not performed.
[0561] 4-9-3. HOLD RECALL is displayed by DN LED when it is held by
the DN.
[0562] 4-9-4. Scroll of Holding Display
[0563] This system allows display scroll of the "I-HOLD" line
(including extension holding). Holding display is done when the
terminal is available. Synchronized with the call reception
information display operation on the LCD, the LED blinks at 10 Hz.
This holding display has been described in (3-7), and a detailed
description thereof will be omitted.
[0564] (4-10) Office Line Transfer
[0565] FIGS. 81, 82, and 83 are views for explaining the delay call
reception operation in ring transfer. FIG. 81 shows the timing for
an extension HFU calling destination. FIG. 82 shows the timing for
an extension tone calling destination. FIG. 83 shows the timing
when the terminal goes on-hook during tone calling and the delay
operation.
[0566] (4-11) SMDR Format
[0567] FIG. 84 is a view showing an example of a speech
communication management record printed by the SMDR 8. As shown in
FIG. 84, items to be recorded include the CO number, the terminal
number, the DN number, the end time of speech communication, the
speech communication time, the call reception time, the transfer
destination terminal number, the ANI/DNIS number, the CLASS
information (calling line number) or dial number, and the DNIS-tag
information/CLASS information (calling line name) or account
code.
[0568] (4-12) Various Call Reception Operations
[0569] FIG. 85 shows the call reception operation in the idle state
assuming that a call (DN200-1) arrives at the idle terminal
(#200).
[0570] FIG. 86 shows the call reception operation during call
reception (when an available DN is present) assuming that a call
(DN200-2) arrives at the terminal (#200) which is receiving a call
(DN200-3).
[0571] FIG. 87 shows the DN key operation during call
reception.
[0572] FIG. 88 shows the call reception operation during speech
communication assuming that a call (DN200-2) arrives at the
terminal #200 which is performing speech communication
(DN200-1).
[0573] FIG. 89 shows the call reception operation during call
reception on a terminal which is performing speech communication
(when an available DN is present) assuming that a call (DN200-3) is
being received by the terminal #200 which is performing speech
communication (DN200-1), and a new call (DN200-2) arrives at the
terminal.
[0574] FIG. 90 shows the call reception operation during call
reception on a terminal which is performing speech communication
(when no available DN is present) assuming that a new call arrives
at the terminal (#200) which is performing speech communication
(DN200-1) and also receiving a call (DN200-3).
* * * * *