U.S. patent number 3,634,826 [Application Number 04/855,669] was granted by the patent office on 1972-01-11 for apparatus for transmission of information.
This patent grant is currently assigned to Uninorm Anstalt. Invention is credited to Siegfried Biedermann.
United States Patent |
3,634,826 |
Biedermann |
January 11, 1972 |
APPARATUS FOR TRANSMISSION OF INFORMATION
Abstract
An apparatus for the transmission of information between a
plurality of stations by means of a common transmission path for
light call installations, light call speaking installations,
speaking installations, surveying installations, remotely operative
installations, person-investigating installations, remote
indicators, remote control means, and the like, which comprise
receivers, an impulse exciter and a counter chain including
flip-flops. The receivers are operated only upon occurrence of a
predetermined binary code in the receivers, the binary code being
delivered by the impulse exciter by means of the counter chain
which includes the flip-flops. A time period section, divided into
two partial time periods, is coordinated to each of the receivers,
and a corresponding receiver is selected by the binary code during
the time period section within one of the part-time periods and
information is transmitted to the receiver within the other of the
partial time periods. Synchronously running counter chains and a
conduit common to all stations are also provided and the counter
chains are connectable with the impulse exciter by means of the
conduit for setting the time period stations. The counter chains
have at least as many flip-flops, as are required for the number of
provided channels corresponding with the binary coding given by the
flip-flops. Decoding circuits respond to the same counter position
and are connected with the counter chains of the stations to be
coordinated relative to each other. A gate is applied to the
conduit. Time gaps, disposed between the impulses of the impulse
exciter applied to the gate serve the transmission of the
information. Upon expiration of at least one of the partial time
periods for the synchronization of the entire installations a
synchronous impulse is transmitted by filling out of the last of
the impulse gaps, and at least one joint main station is provided
for a plurality of extension stations connectable with the
transmission path.
Inventors: |
Biedermann; Siegfried
(Schellenberg, FL) |
Assignee: |
Uninorm Anstalt (Vaduz,
FL)
|
Family
ID: |
25321808 |
Appl.
No.: |
04/855,669 |
Filed: |
September 5, 1969 |
Current U.S.
Class: |
340/12.2 |
Current CPC
Class: |
G08B
3/1008 (20130101); H04Q 5/00 (20130101); G08C
15/12 (20130101) |
Current International
Class: |
G08C
15/00 (20060101); G08C 15/12 (20060101); H04Q
5/00 (20060101); G08B 3/00 (20060101); G08B
3/10 (20060101); H04q 009/00 () |
Field of
Search: |
;340/164,167 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yusko; Donald J.
Claims
I claim:
1. An apparatus for the transmission of information between a
plurality of stations by means of a common transmission path
comprising
a plurality of receiver means for receiving signals and being
operated only upon occurrence of a predetermined binary code,
an impulse exciter means for providing impulses having time gaps
therebetween,
a counter chain including flip-flops operatively connected to said
impulse exciter means,
said impulse exciter means for delivering said binary code by means
of said counter chain including said flip-flops to said receiver
means,
means for providing a time period section, divided into two partial
time periods which are coordinated to each of said receiver
means,
means for selecting a corresponding receiver means by said binary
code during said time period section within one of said partial
time periods and
means for transmitting information to said receiver means within
the other of said partial time periods,
another counter chain, said counter chains running
synchronously,
a plurality of extension stations,
a conduit common to all said stations,
said counter chains being operatively connectable with said impulse
exciter means by means of said conduit, for setting said time
period sections,
said counter chains having at least as many flip-flops as are
required for the number of provided channels corresponding with the
binary code given by said flip-flops,
decoding circuit means responding to a same counter position and
being connected with said counter chains of said stations to be
coordinated relative to each other,
a gate connected to said conduit and said impulse exciter
means,
said time gaps between said impulses of said impulse exciter means
being applied to said gate serving the transmission of
information,
means upon expiration of at least one of said partial time periods
for the synchronization of said apparatus by a synchronous impulse
being transmitted by filling out of the last of said impulse gaps,
and
at least one joint main station being operatively connected to a
plurality of said extension stations connectable with said
conduit.
2. The apparatus, as set forth in claim 1, further comprising
means for transmitting of information with a half-amplitude of said
impulses.
3. The apparatus, as set forth in claim 1, further comprising
means for providing a plurality of successive partial periods for
the transmission of a plurality of different information between
two stations of equal coding.
4. The apparatus, as set forth in claim 3, which includes
additional flip-flops connected with said counter chains for
obtaining said partial periods.
5. The apparatus, as set forth in claim 4, which includes
a synchronous impulse filter means for emitting a return impulse
for said counter chains upon occurrence of a synchronous
impulse.
6. The apparatus, as set forth in claim 5, wherein said main
station includes a main station unit operatively coordinated to
each of said extension stations.
7. The apparatus, as set forth in claim 6, which includes
a phase exciter,
all of said main station units of said main station are connected
with said phase exciter,
said phase exciter including said impulse exciter means,
the latter is connected with said counter chain jointly for all of
said main station units,
and said main station units are connected according to the coding
with outputs of said flip-flops of said counter chain.
8. The apparatus, as set forth in claim 7, wherein
the input of said counter chain is selectively connectable with
said impulse exciter means and said conduit, respectively, whereby,
upon connection of said counter chain with said impulse exciter,
the output of said impulse exciter means as well as the conduit
connected with said counter chain and emitting the synchronous
impulse is connected with said conduit.
9. The apparatus, as set forth in claim 8, further comprising
a locking valve means for delivering with said phase impulses
simultaneously an output for the individual units connected with
said conduit.
Description
The present invention relates to an apparatus for the transmission
of information between a plurality of stations by means of a joint
transmission path for light call installations, light call speaker
installations, speaker installations, surveilling installations,
remotely operating installations, person-investigating
installations, remote indications, remote control arrangements, and
thereon, in which the receivers are operated only, when a
predetermined binary code is delivered by means of an impulse
generator over a counter chain consisting of flip-flops. The
present invention relates first of all to light call-speaker
installations, as they are applied for instance in hospitals for
the transmittal of information between the nurses' rooms and the
patients' rooms, as well as for apparatus for the surveillance of
banks and industrial installations and the like.
The previously known wire-operated installations have the drawback,
that for transmittal of a plurality of different information, for
instance personal calls, counter confirmation, broadcast
transmission, telephone operation on a duplex line, light signal
transmission, circuit call transmission, alarm signal transmission,
and the like, a great number of conduits was required. Furthermore,
expensive relay stations were necessary, which must be arranged as
group or central stations, in order to be able to perform all
circuit functions and transmission paths.
The wireless installations save by the costs of the conduits and
partly also save the relay stations, yet are rather very
complicated in their structure and very sensitive against listening
and disturbances. Only by means of an increased technical
expenditure, selective call installations can be created, which
are, however, no longer economically applicable for a greater
number of extension stations.
It is, therefore, one object of the present invention, to provide
an apparatus for the transmission of information between a
plurality of stations, in which the drawbacks of the known
installations are extensively avoided, wire material is saved, the
possibilities of disturbances against disturbing frequencies are
reduced and in which with a low conduit expenditure a relatively
great number of extension stations can be connected. Relay stations
should as much as possible be omitted. Also an exchangeable traffic
between a plurality of stations is possible. Furthermore the
possibility exists, to permit connecting of portable, additional
stations at any selective points of the installation by plugs.
The wireless installations save the expenses for the conduits, and
partly the relay stations which are, however, very complicated in
structure and very sensitive against listening and disturbances.
Only by increased technical expenditure can the selective calling
installations be created, which, however, are usable for a greater
number of extension stations no longer economical.
By U.S. Pat. No. 3,134,961 and by the analogous German Publication
No. 1,094,638, respectively, already a code selector for the
receiver of a person-calling installation has been known, in which
a calling device is operated only in a predetermined receiver, when
a predetermined binary code occurs on a conduit of the receiver, to
which the selector is supposed to respond, whereby the first
impulse of the arriving code comprising a plurality of successive
impulses within a predetermined time period releases a phase
generator circuit, the control impulses of which switch through
within the cycle of the arriving impulse sequence the operating
cycle of a ring counter, in which the outputs of the individual
steps, switched together corresponding with the own code of the
receiver, are connected with the inputs of a Tor-circuit, in which
the individual impulses of the ring counter steps can be compared
with the individual impulses of the arriving codes and upon
termination of a complete working cycle the impulse of the last
step of the ring counter does not release a call, when an impulse
arriving upon nonconformation with its own code through the
Tor-circuit has prevented the call by a locking circuit, while the
impulse of the last step of the ring counter releases the call, if
upon confirmation of the own code and of the impulses the locking
circuit is open.
The present invention is based on the concept to transmit
information simultaneously from a plurality of extension stations
to a main station and in reverse order, as well as to connect
together main and extension stations by at least two-wire,
particularly three-wire conduits.
In a three-wire trunk, one wire serves as a sending wire, the
second as a receiving wire and the third as a joint return wire.
The indications, sending and receiving wire are hereby defined from
the extension station.
In accordance with the present invention, in the manner of a time
multiplex system, a predetermined time section (participant time
period) is assigned to each receiver, whereby during this
subscriber time period within the one part-time period, the
receiver is selected by the binary code and information is
transmitted within the second part-time period, whereby for the
setting of the subscriber time periods by means of a conduit
jointly for all stations, synchronously running counter chains
connectable with the impulse generator are provided, which have at
least as many flip-flops, as are required for the number of
provided channels corresponding to the binary code given by the
flip-flops. On the counter chains of the stations, coordinated to
each other, decoding circuits, particularly gates, are connected.
The gaps disposed between the impulses applied from the impulse
generator to the conduit serve the transmission of the information.
Upon termination of one or a plurality of partial periods for the
synchronization of the total installation, a synchronous impulse,
particularly by filling out the last impulse gap, is transmitted,
and at least one joint main station is provided for all or a
plurality of stations (extension stations) connectable onto the
transmission path.
Advantageously the transmission of the information by means of
impulses takes place preferably with the half-amplitude of the
frame pulse.
In accordance with a further development of the present invention
for the transmission of a plurality of different information
between two stations of the same code, several successive periods
(partial periods) are provided.
If the impulse generator emits at any position of the conduit
rectangular impulses onto the sending and receiving wire and if n
extension stations are present, at least n impulses form a partial
period. If m informations are transmitted between one extension
station and the main station, at a maximum m partial periods are
joined to one cycle period.
If s is the number of the steps of the counter, the number of the
coding time points per partial period amounts to 2 .sup.s. If the x
extension station exchanges an information with the main station,
by logic connections of the step outputs of the counter chain
present in this unit and of the phase, it can be brought about
that, within the subscriber time period, for instance, a
complementary impulse gap can be raised from the potential "0" to
any selected value, preferably to the half-potential of an impulse.
This information reaches the main station by means of the sending
wire. There the unit coordinated to this extension station
questions this impulse gap and gives an output signal due to the
information contained therein. The main station communicates with
the extension stations by means of the receiving wire in the same
manner.
This synchronous impulse secures the synchronization of all
connected sending and receiving units, so that at all units, the
same counter position sets itself synchronously. Thus to each
counter corresponds a code number of a unit.
The permanent transmission of the code impulses makes possible a
particularly rational solution of the problem of the energy supply,
since in accordance with another feature of the present invention,
the phase impulses deliver simultaneously, for instance by means of
a blocking valve, the output for the individual units connected
with the transmission path.
For the delivery of the output of the individual units connected
with the transmission path, also impulse amplifiers can be
provided, which amplify the transmitted phase impulses. Thereby a
circuit arrangement can be chosen of diodes and condensers, which
takes the energy only from the phase impulses, not, however, from
the information contained in the impulse gaps, in which the diodes
charge the condensers in the supply conduit of each unit of the
installation only in case of an applied voltage, which is for
instance larger than half of the impulse voltage.
Instead of the use of separate sending and receiving wires, for one
of the two directions, further partial periods and subscriber time
periods, respectively, can be used. Thus, for instance, all
even-numbered impulse gaps for information can be used from the
extension station to the main station and all uneven-numbered
impulse gaps for information from the main station to the extension
station.
Further details of the present invention result in the showing in
the drawings in which an embodiment is disclosed for four part
periods, which are applied for the transmission of four different
signals. In the direction from the main station to the extension
stations, these partial periods are, however, not exploited, rather
in all partial periods in this direction only one and the same
signal is sent.
FIG. 1 is a principally simplified circuit of an apparatus in
accordance with the present invention with main station unit, a
common cycle generator and an extension station:
FIG. 2 is a circuit diagram of a phase exciter;
FIG. 3 is an impulse program of the phase exciter disclosed in FIG.
2;
FIG. 4 is a circuit diagram of a main station unit according to
FIG. 1; and
FIG. 5 is a circuit diagram of an extension station according to
FIG. 1.
In all Figures all shown gates are shown as NOR gate.
Referring now to the drawings, and in particular to FIG. 1, by
example the circuit of a main station with an extension station in
accordance with the present invention is disclosed, whereby all
details required for the following explanation have been
omitted.
The main station comprises main station units II of a number
resulting from the number of the extension stations I and a phase
exciter III common to all main station units II. In the phase
exciter III is disposed an impulse exciter 1, which is connected,
on the one hand, to a counter chain 2 constructed of flip-flops,
and, on the other hand, is connected by means of a gate 3 to the
conduit 4. The outputs of the flip-flops of the counter chain 2 are
fed to all main station units II of the main station. Two
additional flip-flops 5 and 6 are connected to the counter chain 2,
which flip-flops 5 and 6 are provided for the production of partial
periods, for which purpose a gate circuit 7 is provided.
To the gate circuit 7 is connected a gate circuit 8 coordinated to
each main station unit II for switching through of the partial
periods. A memory arrangement 9 follows this gate circuit 8, which
memory arrangement contains the memories coordinated to the partial
periods. Selected receivers can be connected to the memory
arrangement 9, which receivers receive the signals transmitted
during the individual partial periods. In FIG. 1 by example one
signal lamp each 10, 11, 12 and 13 is provided therefor.
To the counter chain 2 is connected by means of a gate 14, which
selects the impulse gap of the impulse sequence (coding time
point), characterizing the connected extension station (coding time
point), on the one hand, a calling circuit 15, the input of which
is connected with the conduit 16 connected with all extension
stations I and the outputs of which are connected with the gate
circuit 8, on the other hand, to a gate 17, the output of which is
connected with the conduit 4 and the second output of which is
connected with the output of the sender memory 18, which is
operable by means of a call key 19 or a release key 20.
For the synchronization of the counter chain 2 a synchrone impulse
filter 21 is switched in between the impulse exciter I and the
counter chain 2.
The extension station I equals in principle the structure of the
main station II, III with the exception of a few switching
elements, as for example, the impulse exciter I, which delivers the
phase impulses not only to the counter chain 2 of the main station,
but also by means of the gate 3 and the conduit 4 to the counter
chain 22 of the extension station, at the output of which is
analogously switched to the gate 14 of the main station unit II.
Here likewise are provided flip-flops 24 and 25 for the production
of the partial periods, the calling circuit 26, the sending memory
27, the call key 28, the release key 29 and the synchronous impulse
filter 30.
Since, in this embodiment, shown by example from the main station
II, III, always one and the same signal can be fed to the extension
station in all partial periods, only one signal lamp 31 is provided
here. Since four different signals should be transmittable from the
extension station to the main station in the four partial periods,
the extension station I has a gate circuit 32, which corresponds
with the gate circuit 8 of the main station, but contains in
addition a switching device (not shown in FIG. 1) for the selection
of the partial period and thereby of the desired signal.
The impulse exciter 1 sends continuously phase impulses to the
counter chain 2, as well as to the counter chain 22, whereby the
corresponding stations (extension station and the coordinated unit
of the main station) are coordinated to each other by means of the
gates 14 and 23. The two flip-flops 5, 6, and 24, 25, respectively,
connected with the counter chain 2 and 22, respectively, make
possible in the shown embodiment the production of four partial
periods, so that a total period of four such partial periods is
combined, whereby to each of these partial periods one of the four
signals can be coordinated.
Referring now again to FIG. 1, the function upon pushing the call
key 28 of the extension station I is now explained. By means of the
sending memory 27 in dependency upon the gate circuit 32 the
feeding of the call signal takes place within the partial period
coordinated thereto by impulses in the impulse gap of the impulse
exciter 1 to the conduit 16, which impulse gap is selected by the
counter chain 22 and the gate 23. This signal disposed in the
impulse gap activates the calling circuit 15 within that time
section, which is coordinated by the gate 14 to this main station
unit. By the gate circuit 7 it is determined, within which of the
four partial periods the activation has taken place, whereupon by
means of the gate circuit 8, a memory device of the memory
arrangement 9 which is coordinated to this partial period is
activated, which memory arrangement 9 in turn brings about the
lighting of the signal lamp (10-13) coordinated thereto. Upon
pushing the release key 29 of the extension station I, the sending
memory 27 is reset, whereby the signal in the impulse gap
disappears on the conduit 16, the calling circuit 15 and the memory
of the memory arrangement 9 is returned and the signal lamp is
extinguished.
In reversed order upon pushing the call key 19 of the main station
unit II the sending memory 18 is activated, which opens the gate
17, whereby the impulse selected by the gate 14 is brought to the
conduit 4. Here also an activation of the calling circuit 26 takes
place and a lighting up of the coordinated signal lamp 31. In the
case the sending memory 27 has been set for this time period, it is
returned by the signal, causing the lighting of the lamp 31.
If now a plurality of extension stations is connected with the
conduits 4 and 16, to which extension stations is coordinated at
the main station always a unit thereof, always only one extension
station cooperates with the corresponding unit of the main station.
Thus upon pushing the calling key 28 of an extension station, only
one of the signal lights 10-13 of the coordinated unit II of the
main station lights up, although all extension stations and the
units of the main station coordinated to the latter are disposed at
the same conduits 4 and 16.
It is apparent, that the main station for a plurality of extension
stations contains a joint phase exciter, which comprises the
impulse exciter 1 with the gate 3, counter chain 2, flip-flops 5
and 6, the gate circuit 7 and the synchronous impulse filter 21, as
it is shown clearly in detail in FIG. 2.
The impulse exciter 1 has a rectangular generator (not shown),
which delivers rectangular impulses with the sequence frequency of
1 kilocycle per second. The impulse sequence of kHz. extends over
the gate 3, an amplifier 34 and the switch 35, on the one hand, to
the conduit 4 (FIG. 1) and, on the other hand, over the switch to
the switch 35, serving the switching of the remote synchronization
and the gate 36 to the counter chain 2 (FIG. 1) consisting of the
flip-flops 37, 38, 39, 40, 41, 42 and 43, to which are connected
still the flip-flops 5 and 6 for the partial periods. The gate
switch 7 comprises the gates 46, 47, 48 and 49, which are in
connection with the outputs of the flip-flops 37-43 by means of the
gates 50, 51, 52 and 53.
The synchronization impulse filter 21 serves the return of the
counter chain and comprises the gates 55, 56 and 57, the condenser
58, the resistance 59, the condenser 60 and the transistor 61. The
inverse phase frequency is fed to the synchronous impulse filter 21
by means of the gate 54.
At the end of the fourth partial period, the synchronous impulse,
in form of a last impulse of the total period widened for the
impulse width is brought from the output of the gate 49 by means of
the gate 3 and the amplifier 34, to the conduit 4, so that a
synchronous impulse of treble impulse width is created, as is still
further explained in connection with FIG. 3.
The switch 35 makes it possible in the one (lower) position to feed
the counter chain 2 directly from the impulse exciter 1 and to
supply the conduit 4, as mentioned, with the synchronous phase, so
that all counter chains connected with the conduit 4 are
synchronized. If the synchronous phase of another position is
attached to the conduit 4, the switch 35 is brought into the other
(upper position), whereby the impulse exciter 1 is switched off and
the synchronous phase from the conduit 4 is brought by means of the
filter 62, to the gate 36 and thereby to the counter chain, which
filter 62 serves the removal of disturbing impulses and of
information present in the impulse gaps.
The outputs of the flip-flop 37 to 43, as well as of the gates 46
to 49 are supplied by means of the output transistors 63 to the
terminals 65 to 82.
It is apparent, that by the seven flip-flops 37 to 43 belonging to
one period, totally 2.sup.7 =128 different counting steps result,
whereby due to the synchronous impulses up to 127 independent
extension stations can work together with one main station.
FIG. 3 discloses the impulse program of the phase exciter shown in
FIG. 2.
The impulse program comprises 4.times.128 steps, which are divided
into four partial periods starting at the points t=T.sub.0,
T.sub.1, T.sub.2 and T.sub.3 to 128 phases each (0 to 127). The
characterization of the partial periods takes place such, that
after the synchronous impulse (127) the first part period a starts
with the phase number 0 and terminates with the phase number 127,
to which, at the output 79, an impulse is emitted, which indicates
the end of the first part period. The second part period b is
terminated by an impulse at the output 80, the third part period c
by an impulse at the output 81 and the fourth part period d by an
impulse at the output 82. The impulses at the outputs 79, 80, 81
and 82 are obtained at the outputs of the gates 46, 47, 48 and 49
(FIG. 2) by means of the impulse succession N achieved by the gates
50, 51, 52 and 53.
The impulse succession e, which originates from the overlaying of
the phase frequency 64 and the inverse synchronous impulse 82,
results by the addition e=64 v. 82 in the gate 3.
The function of the synchronous impulse filter 21 is apparent from
the frequency successions S, T, U, whereby the impulse successions
S, T are disposed at the inputs of the gate 57, and the impulse
succession U at the output of the gate 57.
FIG. 4 is a circuit of the main station unit, shown by example
only.
The gates 14 of all main station units having eight inputs each are
connected with the terminal 64-78 such, that each main position
1/127 is coordinated to a partial period. This time period 1/127 of
a partial period is available to each participant within each of
the four part periods. An input of the gates 14 is always connected
with the terminal 64, while the remaining seven inputs are
connected with seven of the 14 terminals 65 to 78 such, that the
counter-stand coordinated to the main station unit all these inputs
have 0-potential.
As in FIG. 1 the output of the gate 14, is disposed jointly with
the output of the transistor 83 of the calling circuit 15, the base
of which is connected with the conduit 16 at the memory device
formed by the gates 84 and 85, the output of which leads to the
gate circuit 8, which is also connected with the outputs 79 and 82
of the phase exciter (FIG. 2), which deliver the impulse
successions 79 to 82, in accordance with FIG. 3. The gate circuit 8
is followed by the memory arrangement 9, which has four memory
circuits coordinated to the signal lamps 10 to 13.
The gate 17 is connected to the output of the gate 14 by means of a
gate 86, the output of the gate 17 being disposed on the conduit 4.
The second input of the gate 17 is disposed at the output of the
memory circuit 18, to which the call key 19 and the release key 20
are connected.
FIG. 5 discloses finally the principal circuit of an extension
station, which discloses in greater detail the extension station I
shown in FIG. 1, for which reason the same parts are identified by
the same numerals.
The counter chain 22 in accordance with FIG. 1 comprises in the
main station flip-flops 87, 88, 89, 90, 91, 92 and 93, to which the
flip-flops 24, 25 are still connected for the partial periods. The
outputs of the flip-flops 87 to 93 are guided to the switches 96,
97, 98, 99, 100, 101 and 102, with which by corresponding switching
of these switches a predetermined participation time period is
selected. By this arrangement that main station unit is
coordinated, which has the same participation time period. These
switches 96 to 102 lead to the inputs of the gate 23, which leads
by means of the gate 121, on the one hand, to the gate 119 and, on
the other hand, to gate 106.
The gate switch 32 (FIG. 1) serving the partial period selections,
comprises four gates 103, 104, 105 and 106, the outputs of which
lead to manually operable switches 107, 108, 109 and 110, which are
disposed by means of a further gate 111 and the sending impulse
amplifier with the transistor 112 at the conduit 16.
To the conduit 4 not only is the counter chain 22 connected, but
also the calling circuit 26, the input of which has a transistor
113, which is connected with a memory circuit comprising the gates
114 and 115. The output of this calling circuit 26 is connected, on
the one hand, by means of a transistor 116 with the signal lamp 31,
and on the other hand, with the input of the sending memory 27,
which is formed of the gates 117, 118. The sending memory 27 is
operable with the calling key 28 and the releasing key 29,
respectively, and leads with its output by means of the gates 119,
120 to the inputs of the gates 103, 104 and 105.
FIG. 5 shows furthermore still a possibility to supply the
extension station with current from the phase impulses emitted on
the conduit 4, for which reason the rectifiers 122 and 123 are
provided.
In the following, the participant time period .tau..sub.1 is
divided into a time section .tau..sub.2 and a time section
.tau..sub.3, as it is shown in FIG. 3 for the phase 1 of the period
a by example. .tau..sub.2 corresponds to the impulse gap for the
transmission of the information between two impulses of the length
.tau..sub.3.
Upon pushing the call key 28 the sending memory 27 is set, whereby
at the output of the latter an 0-signal is created. This 0-signal
is connected in the gate 119 during the time .tau..sub.2 with the
signal, which is secured with the switches 96-102 and is fed by
means of the gates 23 and 121 to the second input of the gate 119
as an 0-impulse. Due to the AND-connection, an 0-signal is created
at the output of the gate 120 during the time period .tau..sub.2.
This 0-signal is fed to the gates 103, 104 and 105, which have at
their inputs likewise AND-connections. With the 0-signal arriving
from the gate 120 and the 0-signals arriving from the outputs of
the flip-flops 24 and 25 during the time period .tau..sub.2, a
1-signal is created at the output of the gate 103 during the first
part period a (FIG. 3), at the output of the gate 104 during the
second part period b and at the output of the gate 105 during the
third part period c. In the fourth d period during the time period
.tau..sub.2 always a 1-signal is created at the output of the gate
106 independently from the sending memory device 27.
By means of the switches 107, 108, 109 and 110, the outputs of the
gates 103, 104, 105 and 106 are set selectively to the inputs of
the gates 111. Due to the OR-connection in this gate 111 just by
closing of the switch 110 the transistor 112 becomes conducting
during the time period .tau..sub.2 in the fourth part period d,
whereby only this impulse with a time period .tau..sub.2 is applied
during the total period (a+ b+ c+d). By closing one of the switches
107, 108 and 109 a 1-impulse is formed during the first part period
a, of the second part period b, on the third part period c for the
time period .tau..sub.2 to the gate 111, as soon as the sending
memory device 27 is set.
It can be recognized that in the shown embodiment, given by
example, three different informations are transmitted from the
extension station to the main station by operation of the calling
key 28, depending which one of these three informations has been
prepared by operation of one of the switches 107 to 109. Upon
closing of the switch 110 a fourth information is transmitted
independently from an operation of the calling key 128. The
impulses emitted in the first, second or third part period (a, b,
c) over the conduit 16 repeat each other within the successive
total periods as long as the sending memory device 27 is returned
by pushing the release key 29. As long as no impulses are
transmitted over the conduit 16, at the output of the gate 14 (FIG.
4) 1-impulses are created in each part period during the time
period .tau..sub.2 within the participant time period .tau..sub.1.
These set the memory device comprising the gates 84 and 85 such,
that at the output of the gate 84 an 0-signal is created. This
0-signal is fed to the outputs of the gates 125, 126, 127 and 128
of the gate circuit 8. As can be ascertained from FIG. 3, an
0-signal is applied to the second input in these gates by means of
the terminals 79, 80, 81 and 82 at the end of each partial period.
Due to the AND-connection on these gates, 1-signals are created at
their outputs, which are fed to the inputs of the gates 133, 134,
135 and 136 at the outputs of which as a consequence 0-signals
occur, so that the signal lamps 10, 11, 12 and 13 remain without
current. Since the gates 133, 134, 135 and 136 are connected with
the gates 137, 138, 139 and 140 to memory devices, this state
remains.
By means of the conduit 16 the sender impulses which are emitted
from the extension station (FIG. 5) reach the transistor 83 of the
calling circuit 15 of the main station unit and render conductive
this transistor, if at the output of the gate 14 at the same time
.tau..sub.2 an 1-impulse is provided. This 1-impulse is created at
this time .tau..sub.2 such, that the inputs of the gate 14 are
connected in the same manner to the outputs of the counter chain 2,
as the inputs of the gate 25 in FIG. 5. By this arrangement the
condenser 124 is charged. Upon termination of the time period
.tau..sub.2 the 1-signal disappears at the output of the gate 14,
the condenser 124 is discharged through the input of the gate 85
and sets the memory circuit comprising the gates 84 and 85 in such
a manner that at the output of the gate 85 an 0-signal is created.
This 0-signal is set to the inputs of the gates 129, 130, 131 and
132.
If for instance in FIG. 5 the switch 110 is selected, the calling
circuit 15 (FIG. 4) is set in each fourth part period within the
participant time period .tau..sub.1 such, that at the outset of the
gate 85 an 0-signal occurs. At the end of the fourth part period an
0-signal occurs at the terminal 82 (see also FIG. 3). Due to the
AND-connection in the gate 132 a 1-signal occurs at the output
thereof and sets the memory circuit comprising the gates 136 and
140 such, that at the output of the gate 136 a 1-signal occurs,
whereby the signal lamp 13 lights up.
If the switch 110 is opened, the sender impulse is missing on the
terminal for the conduit 16, whereby the transistor 83 cannot
become conducting any more. By the output impulses of the gate 14,
the calling circuit 15 is turned back, so that at the output of the
gate 84, an 0-signal occurs. This 0-signal is set among others to
the input of the gate 128, on which at the end of the fourth part
period an AND-connection with the 0-signal at the terminal 82 is
performed. The 1-signal occuring at the output of this gate 124
sets back the memory circuit pertaining to the lamp 13 and the lamp
13 is shut off.
By preselection of the switches 107, 108, 109 (FIG. 5), and pushing
of the sending key 28 in the first, second or third part period an
illumination and extinguishing, respectively, of the lamps 10, 11
and 12 is brought about. By pushing the call key 19 (FIG. 4) of the
main station unit the center memory device is set such, that at the
output of the gate 141 an 0-signal occurs. With this 0-signal and
the output signal of the gate 14 an AND-connection is performed in
the gate 17, so that again within the previously assumed time
period .tau..sub.2 a 1-signal is applied to the conduit 4, on which
are already provided the phase impulses with the synchronous
impulses fed by the phase exciter (FIG. 2). The 1-signal arriving
from the gate 17 falls within all part periods and within the
coordinated participant time period into the particular gap
.tau..sub.2 of the phase impulses. The amplitude of the impulses
emitted from the gate 17 is chosen in this embodiment to such an
extent, that it corresponds approximately to the half-amplitude of
the phase impulses, because for the correct circuit of the counter
chain 22 of the extension station (FIG. 5), the nonfalsified phase
signals must be obtained even when information is transmitted in
the impulse gaps. For this purpose an impulse filter 143 is
provided in the extension station, which, as the impulse filter 62
in FIG. 2, serves the removal of disturbing impulses and of
information disposed in the impulse gaps.
In addition to all other impulses disposed on the conduit 4 in the
selected example during the time period .tau..sub.2 within the
participant time period .tau..sub.1, also the signal impulse
emitted from the gate 17 (FIG. 4) is applied to the base of the
transistor 113. For the same time period .tau..sub.2 the output of
the gate 23 (FIG. 5) delivers a 1-signal to the collector of the
transistor 113. As already explained in connection with the calling
circuit 15 (FIG. 4), the memory circuit formed by the gates 114 and
115 is set such, that at the output of the gate 114 a 1-signal
occurs. This brings, on the one hand, the transistor 116 into the
conducting state, so that the signal lamp 31 lights up, and on the
other hand, the sending memory device 27 as much as it has been set
by the calling key 28, is reversed again, whereby a call coming
from this participant is cancelled. If the release key 20 (FIG. 4)
is pushed, the impulse disappears in the time period .tau..sub.2,
whereby the calling circuit 26 is reversed and the lamp 31 is
extinguished.
While I have disclosed several embodiments of the present
invention, it is to be understood that these embodiments are given
by example only and not in a limiting sense.
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