U.S. patent application number 09/775563 was filed with the patent office on 2001-12-20 for controller.
Invention is credited to Imoto, Masaru.
Application Number | 20010053619 09/775563 |
Document ID | / |
Family ID | 18118879 |
Filed Date | 2001-12-20 |
United States Patent
Application |
20010053619 |
Kind Code |
A1 |
Imoto, Masaru |
December 20, 2001 |
Controller
Abstract
A controller in which a dead space for wiring is reduced, its
input-and-output response time is shortened, and miniaturization
and cost reduction is ensured. A RS-232 connector connection unit
(6) and a peripheral connector connection unit (7) are lowered than
a projection (4) provided with displays (12.sub.1, to 12.sub.4) so
that a cable connector does not exceed the projection (4) when the
connector is mounted on the connector connection units (6) and
(7).
Inventors: |
Imoto, Masaru; (Kyoto,
JP) |
Correspondence
Address: |
William T. Ellis
FOLEY & LARDNER
Washington Harbour
3000 K Street, N.W., Suite 500
Washington
DC
20007-5109
US
|
Family ID: |
18118879 |
Appl. No.: |
09/775563 |
Filed: |
February 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09775563 |
Feb 5, 2001 |
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08979697 |
Nov 26, 1997 |
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6307153 |
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Current U.S.
Class: |
439/55 ;
307/11 |
Current CPC
Class: |
H05K 7/1481 20130101;
H05K 7/1484 20130101; H05K 7/1428 20130101; H05K 7/1479 20130101;
G05B 19/05 20130101; H05K 7/1468 20130101; G05B 19/0423
20130101 |
Class at
Publication: |
439/55 ;
307/11 |
International
Class: |
H02J 001/00; H05K
005/00; H02G 003/08; H01J 015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 29, 1996 |
JP |
8-320204 |
Claims
What is claimed is:
1. A controller comprising a connector connection unit for
connection with a cable connector, a housing having difference in
level and a display disposed on a higher level section of the
housing, one board disposed in parallel with a side wall of said
housing, another board disposed to cross said one board, said one
board being positioned on the higher level section of said housing
and said connector unit on said another board being positioned on a
lower level section of said housing.
2. A controller according to claim 1 in which said difference in
level corresponds to height of a connector connected with said
connector connection unit.
3. A controller according to claim 1 in which said another board is
provided with a power supply circuit and said one board is provided
with a control circuit.
4. A controller according to claim 1 which receives input data from
an input unit through a terminal and produces output data to be
applied to an output unit through said terminal, and further
comprising communication means for executing a serial communication
with said terminal to receive and send said input and output data.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a controller, and more
particularly to an improved device such as a programmable
controller suitable for a sequence control.
[0003] 2. Discussion of the Related Art
[0004] There is well known a controller or a sequence control
system employing a programmable controller, in which a
communication unit as a master station is mounted to a base unit of
the programmable controller, terminals as a plurality of slave
stations are connected to the communication unit, and each of the
terminals is connected by an input unit such as a limit switch or
various sensor or an output unit such as a air valve or an
actuator. In such a well known sequence control system, ON-OFF
input data produced from the input unit such as the limit switch or
various sensor is transferred to the programmable controller
through the terminals, the programmable controller receives the
input data to operate the received data in accordance with a
program set beforehand and generate ON-OFF output data to be
applied to the output unit such as the air valve or actuator
through the terminals, and a machine tool is thus controlled.
[0005] The conventional programmable controller is provided with a
connector connection unit to be connected with a programming tool,
RS232 association components device or the like. When a cable
connector of the programming tool is mounted on the connector
connection unit, the cable connector is kept to externally project
from a main housing body of the programmable controller. That is,
the cable connector mounted on the main housing body of about
rectangular parallelepiped is kept to eternally project bringing a
dead space by the wiring. In the sequence control system, the base
unit of the programmable controller is mounted by the communication
unit employing a communication CPU whereby an input-and-output
response time is delayed because data transmission is delayed
between the CPU of the base unit and the communication CPU of the
communication unit. The base unit of the programmable controller
and the communication unit are separated units, so that an
interface circuit or the like is necessary to be disposed between
the both units and each unit has to be provided with CPU, resulting
into a bulky configuration and expensive controller.
SUMMARY OF THE INVENTION
[0006] It is, therefore, a primary object of this invention to
provide an improved controller in which a dead space for wiring is
decreased, an input-and-output response time is shortened, its
configuration is miniaturized, and its manufacturing cost is
reduced.
[0007] According to a first aspect of this invention, there is
provided a controller including a connector connection unit for
connection with a cable connector, a housing having difference in
level and a display disposed on a higher level section of the
housing, one board disposed in parallel with a side wall of the
housing, another board disposed to cross the one board, the one
board being positioned on the higher level section of the housing
and the connector unit on the another board being positioned on a
lower level section of the housing. The difference in level
corresponds to height of a connector connected with the connector
connection unit. The another board is provided with a power supply
circuit and the one board is provided with a control circuit.
[0008] Since the connector connection unit is placed on the lower
level section of the main body housing, the controller may easily
ensure wiring space by avoiding such conventional inconvenience
that a cable connector projects from the main body housing of the
controller. The one board is positioned in parallel with the side
wall of the housing and the another board is placed to cross the
one board so that they may be effectively accommodated by the
housing having the lower and higher sections, resulting into
miniaturization of the controller. The control circuit mounted on
the one board is separated from the another board provided with the
power supply circuit, so that the control circuit is free from heat
or noise from the power supply circuit and the freedom of mounting
design of the boards is improved.
[0009] According to a second aspect of this invention, the
controller receives input data from an input unit through a
terminal and produces output data to be applied to an output unit
through the terminal, and further includes a communication means
for executing a serial communication with the terminal to receive
and send the input and output data. The controller including the
communication means for receiving and transmitting the input and
output data about the terminal by serial communication does not
need any communication unit which is conventionally necessary as a
master station, so that data transmission speed of this controller
is higher than that of the conventional controller employing the
communication unit existing in the communication.
[0010] According to a modification of the second aspect of this
invention, there is provided a programmable controller further
including a control means for repeatedly executing an input process
for reading input data received by the communication means, an
output process for sending output data to be transmitted to the
communication means, a program execution process for executing a
user program, and other process, the program execution process
being executed between the input process and its subsequent output
process, and the other process being executed between the output
process and its subsequent input process. The communication means
starts in response to the output operation. One communication cycle
of the communication means starts by transmission of the output
data and ends by receipt of the input data following the
transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other objectives and advantages of this invention will be
more readily apparent from the following detailed description
provided in conjunction with the following figures, of which:
[0012] FIG. 1 shows a construction of a control system provided
with a programmable controller as a first embodiment of this
invention;
[0013] FIG. 2 is a perspective view of the programmable controller
block diagram of FIG. 1;
[0014] FIG. 3 is a front view of the programmable controller of
FIG. 2;
[0015] FIG. 4 is a side view of the controller of FIG. 3;
[0016] FIG. 5 is a plan view of the controller of FIG. 3;
[0017] FIG. 6 is a rear view of the controller of FIG. 2;
[0018] is FIG. 7 is a schematic block diagram of the programmable
controller of FIG. 2;
[0019] FIG. 8 is an illustration for explaining a cyclic operation
by the programmable controller;
[0020] FIG. 9 is a timing chart for explaining an input-and-output
response time of the programmable controller;
[0021] FIG. 10 is a schematic sectional view of programmable
controller to explain an internal construction thereof;
[0022] FIG. 11 shows a system employing the programmable
controller.
[0023] FIG. 12 is a construction of a control system provided with
a programmable controller as a second embodiment of this
invention;
[0024] FIG. 13 is a perspective view of the programmable controller
of FIG. 12;
[0025] FIG. 14 is a schematic sectional view of the programmable
controller to explain an internal construction thereof; and
[0026] FIG. 15 is a schematic block diagram of the programmable
controller of FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring, now, to FIG. 1 there is shown a construction of a
control system provided with a programmable controller 1 as a first
embodiment of this invention. The control system includes the
programmable controller 1 and a plurality of terminals 2 as slave
stations which are bus connected with the programmable controller 1
through a cable. Each terminal 2 is connected with an input unit
such as a proximity switch, a limit switch or the like, or an
output unit such as a relay, an actuator or the like, which are not
shown in any drawings. This control system transmits ON/OFF input
data from the input unit to the programmable controller 1 through
terminal 2, and the programmable controller 1 receives the input
data to operate the input data according to a program set
beforehand and produces ON/OFF output data to the output unit
through terminal 2 to control a machine tool. This system is not
necessary to employ any communication unit conventionally required
as a master station, while the programmable controller 1 has a
function as a master station as described later.
[0028] FIG. 2 is a perspective view of the programmable controller
1 of FIG. 1, FIG. 3 is a front view of the programmable controller
of FIG. 2, FIG. 4 is a side view of the controller 1 of FIG. 3, and
FIG. 5 is a plan view of the controller of FIG. 3.
[0029] The programmable controller 1 of this embodiment includes a
main body housing having a front housing 3.sub.1 and a rear housing
32 on a bottom of the controller. A projection 4 is disposed at one
side of a front wall of the front housing 3.sub.1, extending along
a longitudinal direction of the housing (vertical direction in FIG.
3), and a flat section 5 lower than the projection 4 is disposed on
other side of the front wall. In the flat section 5 there are
disposed openings 8 and 9 respectively corresponding to a RS-232C
connector connection unit 6 to connect RS-232C corresponding unit
and a peripheral connector connection unit 7 to connect a
peripheral component, so that the connector connection units 6 and
7 face outwardly of the housing 31 through the openings 8 and 9.
The opening 9 for the peripheral connector connection unit 7 may be
closed by a plastic cover (not shown in drawings) when the
connector connection unit 7 is not used.
[0030] On a lower portion of the front wall of the housing there
are disposed power input terminals 10, and terminal connection
terminals 11 in parallel.
[0031] On an upper wall of the projection 4, there are disposed a
power display (PWR) 12.sub.1 for displaying and monitoring input
power supply, a status display 12.sub.2 for displaying an operation
status of the programmable controller 1, viz., an operation (RUN)
and an error (ERR), a communication status display 12.sub.3 for
displaying data transmission (SD), data receipt (RD) and
communication error (ERC), and a peripheral RS-232C display
12.sub.4 for displaying communication (COMM) with a peripheral unit
or RS-232C association component.
[0032] A difference between the upperwall of the projection 4,
viz., an upper surface of the displays 12.sub.1 to 12.sub.4, and
the flat section 5 provided with openings 8 and 9 of the RS-232C
connector connection unit 6 and the peripheral connector connection
unit 7, that is, a height H of the projection 4 shown in FIG. 5 is
designed to be almost equal to a height of a hood portion of a
cable connector plugged in the connector connection units 6 and 7.
Accordingly, when cable connectors of a RS-232C association
component and a peripheral component are mounted on the connector
connection unit 6 and 7, the height of the hoods of the cable
connectors does not exceed the projection 4. In a conventional
programmable controller employing no difference in level in the
housing, a hood of a cable connector projects from a main housing
of the programmable controller when the connector is connected into
a connector connection unit of the programmable controller,
resulting in production of a dead space. In this embodiment,
however, the hood of the connector connected with the connector
connection units 6 and 7 is positioned to have same height as that
of the projection 4, so that such a dead space is decreased and a
space for wiring is ensured.
[0033] On the rear housing 3.sub.2 of the programmable controller
there is disposed a rail groove 15 along a width direction to
engage the programmable controller 1 with a support rail (not shown
in drawings), as shown in FIGS. 4 and 6.
[0034] On one side edge (upper side edge) in the horizontal rail
groove 15, there are disposed a pair of engagement pieces 43
projecting toward the rail groove 15 on both sides, whereby an
upper engagement portion of the support rail is engaged between the
engagement pieces and a bottom of the rail groove. On other side
edge (lower side edge) in the horizontal rail groove 15 there is
provided a movable plastic engagement lead 16 including three
engagement portions 16b to be engaged with a lower engagement edge
of the support rail, which is positioned crossing the rail groove
15 for a forward-and-backward movement. A lower engagement edge of
the support rail is inserted between the three engagement portions
16b of the movable engagement lead 16 and the bottom of the rail
groove.
[0035] The movable engagement lead 16 is mounted along a pair of
guide grooves 41 formed on the rear housing 3.sub.2 for a slidable
movement. A free end of arm 16a supported at other end thereof
within an internal portion of the movable engagement lead 16 formed
as a single unit comes into contact with a projection 42 projecting
from the bottom housing so that an elastic force of the arm 16a
biases the movable engagement lead 16 toward the rail groove 15. A
lower end of the lead 16 serves as an operation piece 16c for
disengagement which projects by several millimeters from the
housing when the lead 16 is biassed to the rail groove 15 and
includes an operation hole in a front portion of the piece 16c to
be inserted by a screw driver.
[0036] As shown in FIG. 2 and 3, on a pair of corners opposing each
other across a slant direction in a rear wall of the front housing
3.sub.1, there are disposed a pair of mounting holes 17 so as to
mount the programmable controller also by screws. A group of slits
40 are disposed in a proper portion of the front housing 31 to
externally exhaust the heat generated within the housing.
[0037] FIG. 7 is a schematic block diagram of the programmable
controller 1. The programmable controller 1 of this embodiment has
a construction for direct serial communication with terminals 2
without connection by any communication unit as a master station as
described hereinafter.
[0038] The programmable controller 1 includes a microprocessor 18
as a control means for controlling respective components and
executing an operation described later, RAM 19 and ROM 20 as a
program memory, RAM 21 as a data memory, a communication means 22
for executing serial communication with the terminals 2, a RS-232C
interface 23, a peripheral unit interface 24, a power circuit 25
dropping to a d.c. voltage 24 volts for power supply, and a backup
circuit 26 for the power supply.
[0039] The communication means 22 includes a logic gate array 26, a
receiver-and-transmitter 27, a pulse transformer 28 for improving
noise resistance characteristics. The logic gate array 26 converts
parallel output data produced from the microprocessor 18 into
serial data, converts the serial data into a communication format
to be transmitted to the terminals 2 through the
receiver-and-transmitter 27 and the pulse transformer 28 in a
serial transmission format, receives data from the terminals 2
through the pulse transformer 28 and the receiver-and-transmitter
27 to be converted into parallel input data to be applied to the
microprocessor 18. The logic gate array 26 also controls the
communication status display 12.sub.3 for displaying a
communication status between the terminals 2 and the programmable
controller.
[0040] The communication means 22 initiates one communication cycle
in response to an output refresh process in a later-described
cyclic process. The one communication cycle begins by the
transmission of output data to the terminals 2 and finishes by the
receipt of input data from the terminals 2.
[0041] As an output refresh process is executed and output data
from the microprocessor 18 is set to an output register of the
logic gate array 26 for start, the communication means 22 converts
parallel output data into serial data, converts the serial data
into a communication format to be transmitted to the terminals 2
through the receiver-and-transmitter 27 and the pulse transformer
28 in a serial transmission format, subsequently receives data from
the terminals 2 through the pulse transformer 28 and the
receiver-and-transmitter 27 to be set to an input register of the
logic gate array 26 to notify the microprocessor 18 of the
completion of communication. Thus, the microprocessor 18 receives
input the received data after execution of an input refresh process
described later.
[0042] FIG. 8 is an illustration for explaining the cyclic
operation by the microprocessor 18.
[0043] The microprocessor 18 of this embodiment executes an
initialization process upon power activation, a common process (TA)
such as memory check or the like unless there is any error, a
standby process (TG) for waiting completion of one cycle by the
communication means 22, an input refresh process (TF) in which
input data received from the terminal 2 is taken by the
communication means 22, a program execution process (TB) in which a
user program is executed based on the latest taken input data, a
cycle time computing process (TC), an output refresh process (TD)
in which the output data obtained by the program execution process
(TB) is written into the output register of the logic gate array 26
of the communication means 22, a peripheral port service process
(TE) such as a RS-232C port service and a peripheral port service,
and again the common process (TE) to repeat the above-mentioned
processes.
[0044] In this embodiment, the input refresh process is executed to
take the latest input data just before the execution of the program
execution process, the output refresh process is executed just
after the execution of the program execution process and the cycle
time computing process to initiate the transmission of the output
data, whereby the input-and-output response is improved.
[0045] As described above, the one communication cycle by the
communication means 22 begins by the transmission of the output
data to the terminals 2 and finishes by the receipt of the input
data, so that the peripheral service process and the common process
may be performed by effectively using a time from the beginning to
the finish of the communication in response to the output refresh
process, whereby the input-and-output response is further
improved.
[0046] FIG. 9 is a timing chart for explaining the minimum and
maximum input-and-output response time of the programmable
controller of this embodiment. FIG. 9 shows at (A) a variation of
the input of the terminal 2, at (B) contents processed by the
microprocessor 18, at (C) a variation of the output of the terminal
2, at (D) contents processed by the microprocessor 18, and at (E) a
variation of the output of the terminal 2.
[0047] As shown in FIG. 9 at (A) and (B), when there appears a
change of an input before start of the communication time, the
change of the input is taken by the input refresh process TF1 after
the end of the communication time, the program execution process
and the cycle time process are executed in response to the input,
the communication is begun to transmit to the terminal 2 in
response to the subsequent output refresh process TD1, and the
output of the terminal 2 is changed as shown in FIG. 9 at (C).
[0048] As shown in FIG. 9 at (A) and (D), when there appears a
change of the input after start of the communication time, the
change of the input is taken by the input refresh process TF2 after
end of the subsequent cycle communication time because it is not in
time for the current communication cycle, the program execution
process and the cycle time computing process are executed based on
the input, the communication is begun to transmit to the terminal 2
in response to the subsequent output refresh process TD2, and the
output of the terminal 2 is changed as shown in FIG. 9 at (E).
[0049] Though a communication CPU in a conventional communication
unit always continues to communicate with the terminals
independently of a CPU of a base unit so that transmission of
output data have to be waited until end of the former communication
cycle, the communication of this embodiment immediately starts in
response to the output refresh process to initiate the transmission
of the output data and the receipt of the input data. That is, the
control of the microprocessor 18 and the communication by the
communication means 22 are synchronously executed, so that the
communication may be immediately initiated in response to the
output refresh process and the input-and-output response time may
be shortened. Accordingly, analog data may be processed.
[0050] FIG. 10 is a schematic sectional view of the programmable
controller 1.
[0051] Within the main body housing of the programmable controller
1 of this embodiment there are housed a first circuit board 29
placed along the front flat section 5 and a second circuit board 30
standing on one end of the first circuit board 29 and placed along
a projection direction of the projection 4.
[0052] In this embodiment, the first circuit board 29 is provided
with the above-mentioned power supply circuit 25, the respective
connector connection units 6 and 7, and the communication terminals
11 of the pulse transformer 28. The second circuit board 30 is
provided with the microprocessor 18 providing a control circuit,
the logic gate array 26 and other circuits, whereby the heat or
noise generated from the first circuit board 29 is reduced about
the affection to the microprocessor and the like of the second
circuit board 30. Thus, the generator of the noise and heat is
separated from the control circuit, whereby the freedom of design
for mounting is improved. The transmission of the heat also is
reduced by the openings 8 and 9 of the flat section 5 of the front
housing 31.
[0053] If desired, a separator may be disposed within the main body
housing as shown by dotted assumption lines in FIG. 10 so that the
transmission of the heat from the heat generator may be further
reduced.
[0054] The first circuit board 29 is placed horizontally, and the
second circuit board 30 stands within the projection 4, whereby the
internal space of the main body housing is effectively used
resulting into miniaturization of the programmable controller.
[0055] On the circuit boards 29 and 30, there are mounted various
kinds of electronic components 31 providing the above-mentioned
circuits. On the top end of the standing second circuit board 30
there are side view LEDs 32 to illuminate the displays 12, to 124
on the upper wall of the projection 4.
[0056] A border of the projection 4 and the flat section 5 is
formed in a curved surface, whereby it is easily separated from a
metal mold and the mechanical intensity is improved.
[0057] Like a conventional programmable controller, as shown in
FIG. 11, the programmable controller of this embodiment may be
connected with a large scale programmable controller (not shown in
drawings), a personal computer 33, and a display 34 through a
connector connection unit 6 for RS-232C, and may be further
connected with peripheral components such as a programming console
35 through the peripheral connector connection unit 7. If desired,
both programmable controllers 1 and 1 of this invention may be
connected each other through the RS-232C connector connection unit
6 for mutual data transmission.
[0058] FIG. 12 is a construction of a control system provided with
a programmable controller 1.sub.0 as a second embodiment of this
invention.
[0059] The programmable controller 1.sub.0 includes a connector
connection unit and an interface circuit so as to communicate with
distributed controllers 36 and a high speed counter 39 in addition
to the serial communication function with terminals 2, an opening
50 disposed on one side of a projection 4 corresponding to a
connector connection unit as shown in FIG. 13, a connector
connection unit 51 disposed on a second circuit board 30
corresponding to the opening 50 as shown in FIG. 14, and a
corresponding interface circuit 52 as shown in FIG. 15.
[0060] In the system of this embodiment, the programmable
controller 10 transmits a set value such as a revolution speed of a
stepping motor 37 to the distributed controllers 36, the controller
36 controls the revolution speed of the stepping motor 37 based on
the set value so that it notifies the programmable controller 10
when the revolution speed of the stepping motor 37 reaches the set
value, and the programmable controller 1.sub.0 controls an output
unit such as a valve through the terminals 2 based on such notice.
Or, the high speed counter 39 measures an output of an encoder 38
to send the measured output to the programmable controller 10 so
that the programmable controller 10 controls the output unit
through the terminals 2 based on the measured output.
[0061] As another embodiment of this invention, the housing may
employ a seal construction and the connector connection unit may
employ a water-proof construction so that the programmable
controller may be used in the circumstances wet by water and oil.
The programming console RS-232C employs infrared communication to
enhance its circumstance resistance.
[0062] Though the foregoing embodiments employ programmable
controllers, this invention maybe applied to other control
devices.
[0063] While the invention has been described and illustrated with
respect to certain embodiments which give satisfactory results, it
will be understood by those skilled in the art, after understanding
the purpose of the invention, that various other changes and
modifications may be made without departing from the spirit and
scope of the invention, and it is therefore, intended in the
appended claims to cover all such changes and modifications.
* * * * *