JPH09326683A - Device for input or output - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a common hardware board unit for input and output at the time of satisfying the total number of input points regardless of the member of required input points and the number of required output points by turning plural respective connection terminals to a type serving for both input and output. SOLUTION: The light emitting elements D10-D17 for the input of a photocoupler for the input are connected relating to the plural respective connection terminals and a first common terminal TC1 and the opening/closing state of input equipments such as a switch and a sensor, etc., is detected. The light receiving elements P20-P27 for the output of the photocoupler for the output are connected relating to the respective connection terminals and a second common terminal TC2 and the operation of external equipments such as a relay and a solenoid, etc., is controlled. The period W21 of the read operation of detection data from the photocopier for the input and the period W20 of the write operation of control data to a latch means for the control of the external equipments by the photocopier for the output are mutually shifted. Further, the self-diagnostic function of a connection state is achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel input / output board of a computer, a programmable controller, and a device for input or output of general electronic equipment, and relates to an improvement of using both input and output in common. .

[0002]

2. Description of the Related Art Since input and output have opposite signal transmission directions and different circuit configurations, two types of input boards (ie, input units) and output boards (ie, output units) have been conventionally used independently. Exists. Conventionally, in some parallel boards of computers, the input / output of PIO (parallel input / output interface), which is a peripheral IC (integrated circuit) of a microprocessor, can be directly output to an external terminal and used for both input and output. , It is necessary to set in advance by software, that is, a large number of each connection terminals must be set for input or output, which is inconvenient and is a serious problem especially when the number of connection terminals is large. Become.

Moreover, in this prior art, the signal level is
C-MOS (complementary metal oxide semiconductor) or TTL
(Transistor / Transistor logic), and its application is limited because it is extremely low.

[0004]

In an input or output board with a high signal level for directly connecting an input device such as a switch or a sensor or directly driving an output device such as a solenoid such as a relay or a solenoid valve, Since the number of points for each board is as large as 16, 32, 64, the input and output points are always used to the last minute, and when the input points or output points are used with a sufficient balance. The reality is that there are few. As described above, in the prior art, the above-mentioned input points and output points must be individually assigned to each board. Therefore, in a system in which both the input board and the output board are mixedly used, if the number of input points used exceeds the number of input points provided on the input board, the number of output board points is temporarily changed. However, even if there is a margin, it is necessary to newly add an input board that is the same as the input board whose number of points used is insufficient, which causes inconvenience. This also applies to the output board.

An object of the present invention is to provide, among a plurality of connection terminals connected to an external circuit such as an input device or an output device,
The object is to provide a device for input or output which is advantageous in terms of cost and space, by making it possible to reduce the number of unused connection terminals.

FIG. 10 is a simplified electric circuit diagram of the prior art having a self-diagnosis function. The external device 6 which is a load and the power supply 7 are connected to the light receiving elements 3 in each of the plurality of output photocouplers 2 of the output unit 1 via the connection terminals 4 and 5. In order to detect and diagnose the connection state of the output unit 1, an input unit 8 is newly provided. A plurality of input photocouplers 9 of the input unit 8
The lines 13 and 14 are connected to the light emitting element 10 through the connection terminals 11 and 12. When the output light-receiving element 3 is controlled to be conductive, the power source 7 supplies the line 14, the connection terminal 12, the input light-receiving element 10, the connection terminal 11, the line 13, the connection terminal 4, the output light-receiving element 3 and the connection terminal. 5
If the input light-emitting element 10 emits light, the connection state is confirmed to be normal. If the light-emitting element 10 is off, the connection state is disconnected and an abnormality occurs. Is detected. In this way, the self-diagnosis of the connection state can be performed.

In the prior art of FIG. 10 as described above, a new input unit 8 has to be provided for detecting the connection state, resulting in an increase in cost and a further installation space. Moreover, the lines 13 and 14 must be connected, which increases the number of steps. Further, due to the wiring of the lines 13 and 14 on the outside, the reliability of the wiring is deteriorated. Therefore, in the prior art, although it is necessary to detect the connection state, it is practically not performed.

Another object of the present invention is to perform hardware self-diagnosis by using the line 13, in the prior art of FIG.
It is to provide a device for input or output which can be easily and reliably performed without using 14, i.e. without external connection.

[0009]

According to the present invention, (a) a plurality of connection terminals connected to an external circuit, (b) a first common terminal, (c) a second common terminal, and (d). A plurality of input photocouplers provided individually corresponding to the connection terminals, each input photocoupler having an input light emitting element and an input light receiving element for receiving light from the input light emitting element. Then, one end of each light emitting element for input is connected to each connection terminal corresponding to the photocoupler provided with the light emitting element for input, and the other end of each light emitting element for input is connected to the first common terminal. , Such an input photocoupler, and a plurality of switching means provided individually corresponding to the (e) connection terminal, each switching means comprising a switching element and an actuating element for switching the switching element. Have each One end of the switching element is connected to each connection terminal corresponding to the switching means provided with the switching element, and the other end of each switching element is connected to the second common terminal; (F) an operation for controlling the operation of the actuating element,
A device for input or output, comprising: a control means for performing a read operation for reading the output of the light receiving element. Further, according to the present invention, the switching means includes an output light receiving element which is a switching element, and light is applied to the output light receiving element to cause the output light receiving element to perform a switching operation. And a light emitting element for output which is an actuating element that is coupled in the opposite direction to the light emitting element for output.
Further, according to the present invention, a data bus is provided, and the control means causes the actuating element to close or open the switching element in accordance with the control data given through the data bus during the write operation period W20, and follow the write operation period W20. During the read operation period W21, the switching element is maintained in the closed state or the open state, and during the read operation period W21, the detection data from the input light receiving element is read to the data bus. It is characterized in that the connection state of each connection terminal is detected by comparing with the detection data. The present invention also includes (a) a plurality of connection terminals connected to an external circuit, and (b) a first common terminal.
(C) A plurality of input photocouplers provided individually corresponding to the second common terminal and (d) connection terminal, wherein each input photocoupler includes an input light emitting element and an input light emitting element. Input light-receiving element, and one end of each input light-emitting element is connected to each connection terminal corresponding to the photocoupler provided with the input light-emitting element. The end is connected to the first common terminal,
Such an input photocoupler and (e) a plurality of output photocouplers provided individually corresponding to the connection terminals, wherein each output photocoupler has an input direction in which a current flows from each connection terminal. The light receiving element for output is coupled in the opposite direction to the light emitting element, and the light emitting element for output that applies light to the light receiving element for output to switch the light receiving element for output is operated. One end is connected to each connection terminal corresponding to an output or an output photocoupler provided with the output light receiving element, and the other end of each output light receiving element is
Such an output photocoupler connected to the second common terminal, (f) a data bus, and (g) a gate means for responding to a read pulse and deriving detection data given from the input light receiving element to the data bus. And (h) in response to the write pulse, while receiving the write pulse, store the control data to which the data bus for performing the switching operation of the light receiving element for output is stored, and the write pulse is supplied. A latch means for maintaining the stored state even after it disappears and for providing the stored control data to the output light emitting diode, and (i) a processing means connected to the data bus for providing the control data to the data bus. Writing period W
In 20, a write pulse is given to the latch means to perform switching operation of the output light receiving element by the output light emitting element, and in the read period W21 after the write period W20, a read pulse is given to the gate means to detect from the data bus. And a processing unit for performing a read operation for reading data, repeating a write period W20 and a read period W21, and comparing control data and detection data for each connection terminal to detect a connection state. It is a device for input or output.

Briefly stated, the present invention can be used as a parallel input board and a parallel output board of a computer, an input unit and an output unit of a programmable controller and general electronic equipment, and can be controlled by software or an input / output setting device. Instead, each connection terminal can be used as an input or an output. According to the present invention, an input device or an output device may be connected to a connection terminal for both input and output, and this connection terminal can be used for both input and output, so that the total number of input points and output points is, for example, 1 Since it can be assigned to various types of input / output boards (that is, units), it is sufficient to always prepare the minimum number of boards (that is, units), and it is possible to exert a great effect in terms of cost and space. According to the present invention, when an input device that derives detection data, such as a switch and a sensor such as a limit switch that performs an opening / closing operation, is used as an external circuit,
The input device is connected between the connection terminal and the first common terminal via a DC power supply. When the input device is closed and conducts to reduce the impedance, the input light emitting element of the input photocoupler is turned on, the light of the input light emitting element is received by the input light receiving element, and during the read operation period W21. Then, it is given to the control means and read. Further, according to the present invention, when the external circuit is an output device having a direct current impedance such as a relay and a solenoid of a solenoid valve, the output device is connected between the connection terminal and the second common terminal. It is connected in series with the power supply. When the control element controls the actuating element in accordance with the control data in the writing period W20 to make the switching element conductive, a load current flows through the switching element to the output device via the DC or AC power source. The power supply for the input device and the power supply for the output device may be respectively provided as shown in FIG. 8 described later, or FIG.
As described above, a DC power source may be shared by the input device and the output device. Although the switching means may be realized by an output photocoupler, a relay or the like may be used. When a relay is used, the coil acts as an actuating element, and a relay switch that conducts or shuts off by exciting the relay acts as a switching element. In the control means, a control data writing period W20 for causing the switching element to perform a switching operation by the actuating element and a reading period W21 for reading the detection data which is the output of the input light receiving element are staggered in time. Therefore, as described above, the connection terminal can be shared for the input device and the output device, and the data bus can be shared for the control data and the detection data. Therefore, it suffices to prepare connection terminals corresponding to the total number of input devices and output devices, and an efficient configuration can be realized, and the input terminals and output terminals of conventional input or output units can be It is possible to eliminate unused waste as much as possible. Further in accordance with the invention, during the write period W20, the actuating element closes the switching element in accordance with the control data to make it conductive, or opens it to interrupt it and keeps that state at least during the period W21 of the next subsequent read operation,
During this read-out period W21, the detection data output from the input light-receiving element is read out, and the control data is compared with the detection data obtained by the above-mentioned reading to obtain the input light-emitting element, the switching element, the DC power supply, and The connection state of the connection line and the like can be checked and detected for each connection terminal to perform self-diagnosis. For example, in the configuration of FIG. 3 to be described later, in a configuration in which a DC power source is shared for an input device and an output device, a current flows through the input light emitting element when the switching element is conductive, and the switching element is turned on. When is cut off, no current flows in the input light emitting element and the input light emitting element is turned off. Therefore, by monitoring such an operation, the self-diagnosis can be performed as described above. In order to ensure this self-diagnosis, it is also possible to carry out all the connection terminals simultaneously, for example before starting normal operation, for example before starting the factory in the morning. At this time, as shown in FIGS. 3 and 8, the input device and the external device are connected in series with the switches SW11,
Shut off with SW12. The self-diagnosis operation can be performed even during normal driving. Further, according to the present invention, the write pulse is applied to the latch means within the write period W20 in which the control data is applied from the processing means to the data bus, the control data is stored in the latch means, and the output provided in the output photocoupler. The light emitting element for light is turned on / off to perform the switching operation of the light receiving element for output, the output device operates through the light receiving element for output, and the state of this switching operation is to read the detection data that follows next. It is also maintained in the period W21. By checking and detecting whether or not the detected data is a value corresponding to the control data, that is, the value corresponding to the switching operation of the output light-receiving element, the connection state of the input photocoupler, output photocoupler, DC power supply and line is normal. It can be done by checking for and detecting.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an electric circuit diagram showing a part of the configuration of an embodiment of the present invention. I / O unit U
0 can be mounted in a housing of a system including a computer and a programmable controller, that is, a sequencer by a detachable connector, and the input / output unit U0 is mounted on, for example, a printed wiring board.

FIG. 2 is a block diagram showing the overall configuration of a system according to an embodiment of the present invention. The input / output unit U0 shown in FIG. 1 and the input / output units U1 to U15 having the same configuration as the input / output unit U0 are connected to a processing circuit 17 realized by a microprocessor or the like via a data bus 16 or the like. A memory 18 including a read-only memory in which a user program is stored and a random access memory in which a calculation result is stored is connected to the processing circuit 17, and a display for displaying input / output data and the self-diagnosis result. The output means 19 is connected. The display connection means 19 may be configured to visually display a liquid crystal, a cathode ray tube, or the like, or print and display on a recording paper by a printer. The input / output units U0 to U15 are connected to input devices indicated by reference numerals S10 to S150, and reference numerals L11 to L1.
The output device indicated by 57 is connected. The input device may be, for example, a limit switch and a sensor, and the output device may be, for example, a relay and a solenoid.

Referring again to FIG. 1, the input / output unit U0
Is a plurality (8 in this embodiment in total) of connection terminals T connected to external circuits that are input devices and output devices.
0 to T7, a first common terminal TC1, and a second common terminal TC
2 are provided. Furthermore, the data bus 1 is connected to the processing circuit 17.
Terminals D0 to D7 individually corresponding to the connection terminals T0 to T7 connected via 6 and a terminal A for address signals
0 to A3 and signal terminals R / W for reading / writing
And a terminal STP for strobe pulse. These reference signs may also be used to represent signals.

Coupling circuits CPL0 to CPL7 are provided corresponding to the connection terminals T0 to T7 individually. Each of the coupling circuits CPL0 to CPL7 includes an input photocoupler PH10.
.About.PH17 and output photocouplers PH20 to PH27. The input photocouplers PH10 to PH17 include light emitting elements D10 to D17 which are input light emitting diodes,
Input light receiving elements P10 to P17 which are phototransistors that receive light from the light emitting elements D10 to D17. The cathodes of the light emitting elements D10 to D17 for input are connected to the connection terminals T0 to T0 corresponding to the photo couplers PH10 to PH17 for input including the light emitting elements D10 to D17 for input.
Each is connected to T7. This input light-emitting element D1
Display light-emitting diodes D30 to D37, which are arranged in proximity to the connection terminals T0 to T7, are connected in series to 0 to D17, and a current limiting resistor is interposed.
One end of each of the input light receiving elements P10 to P17 has a gate means 2
1 and the positive electrode of the DC power supply 22 via pull-up resistors R20 to R27. The other ends of the light receiving elements P10 to P17 are grounded via the line 23 and are connected to the negative electrode of the DC power supply 22. The display light emitting diodes D30 to D37 may be omitted.

One ends of the output photodetectors P20 to P27 in the output photocouplers PH20 to PH27 have connection terminals T0 to T7 corresponding to the output photocouplers PH20 to PH27 provided with the output photodetectors P20 to P27.
, Respectively. These output light receiving elements P2
The other ends of 0 to P27 are connected to the second common terminal TC2. The output photocouplers PH20 to PH27 have output light emitting elements D20 to D27 which are light emitting diodes that give light to the output light receiving elements P20 to P27. Connection terminal T
The direction in which the current flows when viewed from 0 is the light receiving element P20 for output.
And the input light-emitting element D10 are coupled in opposite directions, which is the same for the remaining connection terminals T1 to T7. Thereby, for example, a current can flow through the output light receiving element P20 and the input light emitting element D10.

One end of each of the light emitting devices D20 to D27, which is a cathode, is connected to a latch means 24 realized by an integrated circuit through a current limiting resistor. The other ends, which are the anodes of the light emitting elements D20 to D27, are connected to the positive electrode of the DC power supply 22. Latch means 24
Serves to connect or disconnect the one ends of the light emitting devices D20 to D27 to the negative electrode of the DC power supply 22 in accordance with the control data. The gate means 21 and the latch means 24 are connected to the data bus 16. Data bus 16 terminal D0
~ D7 individually correspond to the connection terminals T0 to T7 as described above.

The input / output unit U0 has an address setter 25 implemented by, for example, a DIP switch.
Is provided, an address for identifying the input / output unit U0 is set, and is provided to the control circuit 36. The control circuit 36 controls the address signals A0 to A from the processing circuit 17.
When 3 is given, if the address set by the address setter 25 matches, the write pulse is sent to the line 26.
To the latch means 24. As a result, the latch means 24 stores the parallel control data from the data bus 16 and controls the light emitting elements D20 to D27 for lighting to be turned on / off, and accordingly, the light receiving element for output P20.
~ P27 conducts / interrupts to perform switching operation. The latch means 24 rewrites, updates and stores the control data from the data bus 16 every time when the write pulse is applied from the line 26, that is, the control data storage state is maintained even after the write pulse 26 is cut off.

The control circuit 36 also includes an input / output unit U0.
When an address signal for specifying is supplied from the processing circuit 17, a read pulse is derived on the line 27 and applied to the gate means 21. Thereby, the gate means 21 derives the detection data having the level corresponding to the switching state, which is the conduction / interruption of the light receiving elements P10 to P17 for input, to the data bus 16 and the processing circuit 1 via the terminals D0 to D7.
7 in parallel.

In FIG. 3, the input device S is connected to the input / output unit U0.
10 is a partial electric circuit diagram showing a state in which 10 and the output device L11 are connected. One end of the input device S10 is connected to the connection terminal T0, and the other end is connected to the switch SW11 and the negative electrode of the DC power supply 29 via the input device common connection point 28, and the positive electrode of the power supply 29 is the first. Common terminal TC
Connected to 1. The negative electrode of the power supply 29 is the switch SW11.
At the same time, it is connected to the second connection terminal TC2. Output device L
One end of 11 is connected to the connection terminal T1 and the other end is
The output device common connection point 31 of the output device L11 and the switch SW12 are connected to the positive electrode of the power supply 29 and the first common terminal TC1.

FIG. 4 is a diagram showing the overall operation of the embodiment of the present invention shown in FIGS. 1 to 3 in a simplified manner. FIG.
As shown in (1), the power supply of the system is at time t1.
Then, the processing circuit 17 causes the input / output units U0 to U15 to be supplied with the address signals A0 to A3 every period W10 in the same periods W1, W2, W3, ... As shown in FIG. The operation of the output device connected to these input / output units U0 to U15 by addressing is controlled by the control data, and the detection data from the input device is read. In the present system, prior to each operation of controlling the output device and reading the input device, as shown in FIG. 4C, in the first periods W1 and W2 from time t2 to t4, the input / output units U0 to U15 The connection state is detected and self-diagnosis is performed, and in the subsequent periods W3, W4, ... After time t4, reading of the input device for normal operation and control of the output device are performed.

In the periods W1 and W2 in which the self-diagnosis is performed, as shown in FIG.
As shown in (3), the switches SW11 and SW12 shown in FIG.
In the subsequent periods W3, W4, ..., these switches SW1
1 and SW12 are kept in a conductive state. The control of these switches SW11 and SW12 may be performed by the processing circuit 17, or the time from t2 to t4 is set by the timer according to the turning-on operation of the power switch at time t1 shown in FIG. 4 (1). , These switches S
The switching states of W11 and SW12 may be controlled.

FIG. 5 is a waveform diagram for explaining a specific operation of the input / output unit U0 during the above-mentioned period W1 of FIG. The operation in the period W1 shown in FIG. 5 is repeated at the same timing in the subsequent periods W2, W3, ... However, the write data as the control data is different. 5 (1) to 5 (4) show the processing circuit 17
To the address terminal A0 of each input / output unit U0 to U15
The waveform of each bit of the address signal given to A3 is shown. By the address signals A0 to A3 of each bit,
As described above, the input / output units U0 to U15 are addressed and the address signal A matched with the address setter 25
Given 0-A3, one of the addressed I / O units U0-U15 will read the input device and control the output device within each period W0.

The period W10 for each of the input / output units U0 to U15 is, for example, 10 μsec, and thus the period W1 = W2 = W3 = ... = 160 μsec. In such a short period W1, W2, W3, the output device L11 that requires driving power such as the relay and the solenoid of the solenoid valve does not operate. For the output device to operate, for example, 100 msec or more, It is necessary that the output light receiving elements P20 to P27 continue to be conducted or cut off. In order to operate the output device according to the control data, the latch means 24 is provided as described above and latches and holds the control data.

FIG. 5 (5) shows the data transmitted by the data bus 16. First two cycles W after power is turned on
In 1 and W2, self-diagnosis, which is the detection of the connection state, is performed.
Therefore, in the first cycle W1, the control data A100, which is write data, is given to all the units U0 to U15, and in the next cycle W2, the control data A200 is given to all the units U0 to U15, and then the normal operation is performed. In the cycles W3, W4, ... In which the control is performed, the control data is set to the data for the operation of the connected external device. In the following description, the period W1 is mainly described, but the same applies to the other periods W2; W3, W4, ....

In each period W10 in which each of the input / output units U0 to U15 is addressed, the processing circuit 17 applies the read / write signal shown in FIG. 5 (6) to the terminal R / W. This signal R / W becomes H level in the first period W20 in each period W10, and
Control data A10 for writing to control the output device
0, A100, A100, ... Are given, and the next period W2
At 1, the logic level is inverted to L level in order to read the detection pulse from the input device, and the read data B
, 100, B100, B100, ... Are led to the data bus 16.

The processing circuit 17 derives the strobe pulse STP shown in FIG. 5 (7). This strobe pulse STP has a write period W20 and a read period W21.
At H, only H30 and W31 are shorter than those
It becomes the level and is at the L level in the remaining period. The control circuit 26 responds to the address signals A0 to A3, the write / read signal R / W and the strobe pulse STP, and when the address signals A0 to A3 match the address set by the address setter 25, the line 26 As shown in FIG. 5 (8), the write pulse which is at the H level for the period W30 is led to the line 26 and given to the latch means 24, and at the next period W31, the H level of the H level shown in FIG. 5 (9). The read pulse is led to the line 27 and the gate means 2 is provided.
Give to 1.

FIG. 6 is a memory map diagram showing a stored state of the memory 18. In the memory 18, for each connection terminal T0 to T7 of each input / output unit U0 to U15, control data for controlling an external device for each connection terminal T0 to T15,
Areas for storing the detection data from the input device are provided respectively. The control data and the detection data are binary signals consisting of 1 bit. Based on the control data and the detection data, the self-diagnosis results of the self-diagnosis periods W1 and W2 and the respective data in the subsequent normal operation periods W3, W4, ... Are stored in the memory 18 in the input / output units U0 to U0.
It is stored for each of the connection terminals T0 to T7 of U15, whereby an abnormality in the connection state can be always detected, and self-diagnosis is performed.

FIG. 7 is a flow chart for explaining the operation of the processing circuit 17. The period W1 in which the self-diagnosis is performed by turning on the power by moving from step a1 to step a2.
It is determined whether or not it is W2. First, when it is the period W1, the process proceeds to the next step a3, and in each period W10 of each unit U0 to U15 in the period W1, as shown in FIG. 5 (1) to FIG. 5 (4). Address signals A0 to A shown
3 (generally indicated by ADD) is derived. Period W1,
In W2, the switches SW11 and SW12 are the same as those in FIG.
As shown in (3), the cutoff state is set.

At step a4, the control data A100, which is the write data supplied to all the connection terminals T0 to T7 in all the input / output units U0 to U15, is set to the logic "0". The control data of this logic "0" means the output photocouplers PH20 to PH20.
This is a signal for shutting off the phototransistors P20 to P21 in H27. The control data A100 is derived from the processing circuit 17 in the period W20 shown in FIG. 5 and stored in the latch means 24 in the write pulse period W30 in FIG. 5 (8). Each is given to D27. Thus, in the period W1, the output light emitting elements D20 to D27 remain off, and accordingly, the output light receiving elements P20 to D27.
P27 remains blocked.

In FIG. 3, the light receiving element P20 for output is used.
In the state where the current is cut off, the current from the positive electrode of the DC power supply 29 passes through the first common terminal TC1, the input light emitting element D10, the display light emitting diode D30, and the conductive output light receiving element P20 to the second common terminal. A closed loop that flows from TC2 to the negative electrode of the power supply 29 is not formed. Therefore, the input light emitting element D20 is turned off when the output light receiving element P20 is conductive. Similarly, the output light receiving element P
When 21 is cut off, from the positive electrode of the DC power supply 29, the first common terminal TC1, the input light emitting element D11, the display light emitting element D31, the output light receiving element P21, and the second common terminal TC2 of the DC power supply 29 are passed. A closed loop in which current flows through the negative electrode is not formed.

In step a5, the read pulse shown in FIG. 5 (9) is applied to the gate means 21 during the period W31 in the read period W21, and the data bus 16 receives the light receiving elements P10 to P17 of the input photo couplers PH10 to PH17.
In the period W31, the detection data from is supplied to the processing circuit 17 from the gate means 21 via the data bus 16, and the detection data is read and stored in the memory 18. As described above, for example, when the input light receiving element D10 is turned off and the connection state is normal, the corresponding input light receiving element P10 is conductive, and its output is at the H level. The output is the detection data of logic "0", and therefore the detection data from the input light receiving element P10 from the data bus 16 is logic "0". When the output light-receiving element P21 is cut off, the input light-emitting element D11 is turned off, and accordingly, the input light-receiving element P11 is cut off, and the detection data is derived as logic "0". become.

At step a6, it is judged whether all the detected data are logic "0" corresponding to the control data of logic "0", and if so, it is judged that the connection state is normal. Then, the process proceeds to the next step a61.

In step a61, the processing circuit 17 increments the address signal ADD by 1 in order to address the next input / output unit U1, and in the next step a62, the address signal ADD changes the input / output unit U0. The number N of U15 (N = N in this embodiment)
If less than 16), the process returns to step a3 again.

In the first cycle W1 of self-diagnosis, after the self-diagnosis operation when the control data is logic "0" in all the input / output units U0 to U15 is completed,
Move to next step a7.

In step a7, the next self-diagnosis cycle W
2, all input / output units U0 in period W20
The signal of logic "1" which is cut off by the output light receiving elements P20 to P27 of U15 to U15 is derived.
In step 31, the input light emitting elements D10 to D17 are turned on, and the outputs of all the input light receiving elements P10 to P17 are at the L level, that is, it is determined in step a9 whether the detection data is logic "1". . Thus, self-diagnosis period W
2, the control data is logic "1", and when the output light receiving elements P20 to P27 are conductive,
The light emitting elements D10 to D17 for input are turned on and the light receiving elements P10 to P17 for input are conducted, the output thereof is at L level, and the detection data is logic "1". Is judged to be normal.

In the next step a10, the input / output units U0 to U15 are sequentially addressed one by one. When the address signal indicated by the reference symbol ADD exceeds the number N of the input / output units U0 to U15 (16 as described above in this embodiment) in step a63, the process returns from step a63 to step a7 and the next input / output is performed. The operation after the unit U1 is repeated in steps a2 to a17.

When the control data and the detected data do not correspond to each other as described above in steps a6 and a9, the self-diagnosis result is judged to be abnormal, and in step a11, the display output means 19 indicates that an abnormal state has occurred. It is output, and the sound display is output with a buzzer.

As a result of the self-diagnosis in the periods W1 and W2,
If no abnormality has occurred in the connection state, the process proceeds from step a2 to step a12, and in the period W3 and thereafter, the output device connected to the input / output units U0 to U15 is controlled and the detection data is read from the input device. At step a12, the switches SW11,
SW12 remains conductive. In step a12,
In the period W3, the input / output unit U0 is addressed, the control data is written in the latch means 24 and stored,
The stored state is maintained, whereby the output light-emitting elements D20 to D27, and thus the output light-receiving elements P20 to P20.
27 performs a switching operation corresponding to the control data to operate the output device connected to at least a part of each of the connection terminals T0 to T7.

At step a14, the detection data from the input device is read through the gate means 21.

Thereafter, in step a15, self-diagnosis is carried out for the connection terminal to which the output device is connected even during the normal operation. First, when the control data given from the processing circuit 17 for shutting off the light receiving element for output, for example, P21, to which the output device is connected in the input / output unit U0 is logic "0", the connection to which the output device L11 is connected Since the input light emitting element D11 corresponding to the terminal T1 is turned off, the input light receiving element P11 is cut off, the detection data is logic "0", and thus it is determined that the connection state is normal at this time. It If the control data is logic "1" and the output light-receiving element P21 is in the conductive state, the input light-emitting element D11 corresponding to the connection terminal T1 to which the output device is connected is turned on and input. The light-receiving element P11 for conduction becomes conductive and the detection data becomes logic "1". At this time, it is determined that the connection state is normal. In step a15 of such self-diagnosis, a normal or abnormal connection state is detected based on the control data for the operation of the output device and the detection data from the input device.

If it is determined to be abnormal in step a16, abnormality processing is performed in step a11, and if not abnormal, the next input / output units U1 to U15 are sequentially addressed in step a17, The same operation is repeated after returning to a2.

In another embodiment of the invention, the switch S
W11 and SW12 are kept in the same conductive state as in the normal operating state, and when the factory starts, the steps a3 to a6, a61, a62, a7 to a10, a6 in FIG.
The self-diagnosis operation of 3, a11 may be performed. At this time, all the control data are set to logic "0", and the connection terminal t to which the output device is connected in step a6.
If the input light emitting elements D10 to D17 corresponding to 0 to t7 are turned off and therefore the detected data is logic "0", it can be determined that the connection state regarding the output device is normal. Further, in step a7, all the control data are set to logic "1", and the input light emitting element D1 corresponding to the connection terminals t0 to t7 to which the output device is connected.
If 0 to D17 are lit and the detected data is logic "1", it can be determined that the connection state of the output device is normal. As described above, the periods W1 and W2 are 160 μsec, for example, and the time required for the output device to operate is 100 msec, for example.
Much shorter than the above, and thus such periods W1, W
In 2, there is no possibility that the output device will operate undesirably.

FIG. 8 is an electric circuit diagram showing a part of the configuration of another embodiment of the present invention. In this embodiment, the input device DC power source E1 is connected to the input device common connection point 28 via the switch SW11 at the first common terminal TC1. An external device DC power source E2 and a switch SW12 are connected in series to the second common terminal TC2, and are connected to an external device common connection point 31.

In still another embodiment of the present invention, a relay 37 as shown in FIG. 9 may be used instead of the output photocouplers PH20 to PH27. This relay 3
Reference numeral 7 denotes an output light receiving element P2 in the above-described embodiment.
Relay switch 38 which is a switching element corresponding to 0 to P27, and relays corresponding to the output light emitting elements D20 to D27 in the above-described embodiment as an operating element which conducts / shuts off the relay switch 38 to perform a switching operation. The relay switch 38 may be configured to include a coil 39, and the relay switch 38 may be turned on or off when the relay coil 39 is excited, and the relay switch 38 may be turned off or turned on when the relay coil 39 is demagnetized.
In the embodiment of the present invention shown in FIG. 8 described above, when the relay 37 shown in FIG. 9 is used instead of the output photocouplers PH20 to PH27, the power source E2 for the output device is used.
May be a DC power supply, but may be an AC power supply.

[0045]

As described above, according to the present invention, an input photocoupler and a switching means such as an output photocoupler for output are connected to each of the plurality of connection terminals in an associated manner. When preparing and configuring a unit configured as in the above-mentioned prior art for input or output having a predetermined number of connection terminals, the total number of input points and output points of the connection terminals If the score is satisfied, the device for the input or output can be used. As a result, the connection terminals can be used efficiently, the cost can be reduced, and the installation space can be saved.
For example, when a unit for input or output of the present invention having 16 connection terminals is configured, when a certain system requires 18 input points and 9 output points, the total number of points is 27 points (= 18 + 9). To be satisfied
It is sufficient to prepare two units for the input or output. On the other hand, when using the input unit having the number of connection terminals of 16 inputs and the output unit having the output point of 16 points in the prior art, the input of the prior art is required to satisfy the input 18 points required in a certain system. Two units are prepared, and one output unit is prepared to satisfy the output of 9 points, and thus a total of three units are required. In the prior art, the number of unused connection terminals in the input device and the output device is large. The present invention solves such prior art problems.

As described above, according to the present invention, in a so-called building block type system using a single or a plurality of units for input or output having a predetermined number of connection terminals, a so-called building block type system is used. Unused connection as compared to a system having a building block type in which one or a plurality of input units having a predetermined number of connection terminals and one or a plurality of output units having a predetermined number of connection terminals are used in combination The number of terminals can be reduced, the configuration can be simplified, and the cost and the installation space can be reduced.

Particularly according to the present invention, a unit for input or output cannot be added as needed,
In a so-called stationary system, it is advantageous compared to the building block type described above. For example, in a conventional programmable controller, there are types in which (the number of input points and the number of output points) are (6, 4), (8, 4), (10, 6) and (12, 8), and these ( The number of input points and the number of output points are fixed in each programmable controller. In the prior art, among such programmable controllers, in a system which has already used (input points, output points) = (6,4), if the modification requires 7 input points, the output is Even if you use only 2 points,
The programmable controller of (6, 4) cannot be continuously used as it is, and the programmable controller of (8, 4) must be newly replaced, resulting in a large cost increase. In the prior art, for example,
If the number of input points and the number of output points are known from the beginning of the system installation and there is a high possibility that these points will not be changed in the future, the programmable controller of the above (8, 4) of the class with one input point higher. If you select and install it, you can suppress the increase in cost as much as possible, but if there is a situation that requires a large number of points beyond the input points, when there are extra output points, Even so, a new programmable controller with more input points must be installed instead of the programmable controller already used. In practice, this often happens shortly after the start of operation of the programmable controller, or a year or two after.

According to the invention, each of the plurality of connection terminals can be used both for input and for output, so that, for example, the programmable controller itself used as the system must be replaced. You can eliminate the need to avoid as much as possible.

According to the present invention, the input photocoupler and the switching means must be connected in association with each connection terminal, but such an input photocoupler and switching means generally have a simple structure. However, it is easily and cheaply commercially available, and therefore practically causes little cost increase.

Furthermore, according to the present invention, each connection terminal is not configured to be preset for input or output by a presetter or software such as a microcomputer, which is advantageous in terms of usability. is there. This saves the setting work, especially when the number of connection terminals is large, and is therefore one of the important effects of the present invention.

Moreover, it is advantageous that the input device or the output device can be detached and replaced and reconnected to the connection terminal at any time during the operation of the system.

According to the present invention, the excellent effect that the connection state of the input photocoupler, the switching means, the connection line and the power supply can be self-diagnosed is also achieved. By making the switching element of the switching means conductive, it is possible to form a closed loop that causes a current to flow to the input light emitting element of the input photocoupler via the power supply. Such a self-diagnosis function is possible in a state where either one or both of the input device and the output device are connected to each connection terminal. As described with reference to FIG. 11 described above, the prior art has a disadvantage that wiring work must be performed between the connection terminal and the external device in order to achieve the self-diagnosis function, which results in an increase in cost. Therefore, in many cases, the above-mentioned problems of the prior art are realized with a slight increase in cost, but it is possible to easily make a highly reliable system.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing an input / output unit U0 which constitutes a part of an embodiment of the present invention.

FIG. 2 is a block diagram showing an overall configuration of a system according to an embodiment of the present invention.

FIG. 3 is a partial electric circuit diagram showing a state in which an input device S10 and an output device L11 are connected to the input / output unit U0.

FIG. 4 is a diagram showing a simplified operation of the embodiment of the present invention shown in FIGS.

5 is a waveform diagram for explaining a specific operation in periods W1 and W2 in FIG. 4 described above.

FIG. 6 is a memory map diagram showing a stored state of the memory 18.

FIG. 7 is a flowchart for explaining the operation of the processing circuit 17.

FIG. 8 is a partial electric circuit diagram of another embodiment of the present invention.

FIG. 9 is an electric circuit diagram of a relay 37 used in place of the output photocouplers PH20 to PH27.

FIG. 10 is a simplified electrical circuit diagram of the prior art.

[Explanation of symbols]

 16 Data Bus 17 Processing Circuit 18 Memory 19 Display Output Means 21 Gate Means 22 DC Power Supply 24 Latch Means 25 Address Setter 28 Common Connection Point for Input Equipment 29 Power Supply 31 Common Connection Point for Output Equipment 36 Control Circuit 37 Relay 38 Relay Switch 39 Relay coil U0 to U15 Input / output unit L11 to L157 Output device S10 to S150 Input device T0 to T7 Connection terminal TC1 1st common terminal TC2 2nd common terminal CPL0 to CPL7 Coupling circuit PH10 to PH17 Input photocoupler PH20 to PH27 Output photocoupler D10 to D17 Light emitting element P10 to P17 Light receiving element P20 to P27 Output light receiving element

Claims (4)

[Claims] 1. A plurality of connection terminals connected to an external circuit, (b) a first common terminal, (c) a second common terminal, and (d) connection terminals individually corresponding to each other. A plurality of input photocouplers, each input photocoupler having an input light emitting element and an input light receiving element for receiving light from the input light emitting element. One end is connected to each connection terminal corresponding to the photocoupler provided with the input light emitting element, and the other end is connected to the first common terminal. (E) A plurality of switching means provided individually corresponding to the connection terminals, each switching means having a switching element and an actuating element for switching the switching element. Such a switching means, one end of which is connected to each connection terminal corresponding to the switching means provided with the switching element, and the other end of which is connected to the second common terminal; An apparatus for input or output, comprising a control means for controlling the operation of the actuating element and a read operation for reading the output of the light receiving element. 2. The switching means comprises an output light receiving element, which is a switching element, and light is applied to the output light receiving element to cause the output light receiving element to perform a switching operation. 2. A device for input or output as claimed in claim 1, characterized in that it is an output photocoupler having an output light-emitting element which is an actuating element which is reversely coupled to the output light-emitting element. 3. A data bus is provided, and the control means is: the actuating element closes or opens the switching element in accordance with control data provided via the data bus during the write operation period W20, and follows the write operation period W20. During the read operation period W21, the switching element is maintained in the closed state or the open state, and the detection data from the input light receiving element is read to the data bus during the read operation period W21. The device for input or output according to claim 1, wherein the connection state is detected for each connection terminal by comparing with the detection data. 4. (a) a plurality of connection terminals connected to an external circuit; (b) a first common terminal; (c) a second common terminal; and (d) a connection terminal. A plurality of input photocouplers, each input photocoupler having an input light emitting element and an input light receiving element for receiving light from the input light emitting element. One end is connected to each connection terminal corresponding to the photocoupler provided with the input light emitting element, and the other end is connected to the first common terminal. , (E) A plurality of output photocouplers provided individually corresponding to the connection terminals, wherein each output photocoupler has a direction opposite to that of the input light emitting element in the direction of current flow seen from each connection terminal. Output light receiving element coupled to the It has an output light emitting element that applies light to the light receiving element to switch the output light receiving element, and one end of each output light receiving element corresponds to an output or an output photocoupler provided with the output light receiving element. Responsive to such an output photocoupler connected to each connection terminal and each output light-receiving element to the second common terminal, (f) a data bus, and (g) a read pulse. , A gate means for deriving the detection data given from the input light receiving element to the data bus, and (h) a data bus for responding to the write pulse and for switching the output light receiving element while receiving the write pulse. Store the given control data,
Latch means for maintaining the stored state even after the write pulse is not given and for giving the stored control data to the output light emitting diode; and (i) a processing means connected to the data bus, Write period W20 in which control data is given to
Inside, the write pulse is given to the latch means to perform the switching operation of the output light receiving element by the output light emitting element, and the read pulse is given to the gate means in the read period W21 after the write period W20 to detect the data from the data bus. A read operation for reading, a write period W20 and a read period W21 are repeated, and control means and detection data are compared for each connection terminal to detect a connection state. A device for input or output.