JPH0962303A - Duplex controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duplex controller which attains its system switching by means of the software and with no use of the hardware and then switching only its input/output part when this part has a simple fault. SOLUTION: Both A and B system CPU parts 12 and 13 contain the system switching functions consisting of the software which transmit and receive the signals for switching both systems. Therefore, if the self-diagnostic function of the part 12 set in a control state detects a fault and this fault includes the parts other than an A system input/output part 14, the system switching function sets the A system in a standby state and also sends an enabling signal to the B system to sets this system in a standby state via the system switching function. If the fault is confined within the part 14, the system switching function continues a standbay state via a B system input/output part 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stand-by redundancy system digitized duplex controller for controlling a plant or the like.

[0002]

2. Description of the Related Art FIG. 11 shows, for example, JP-A-60-23754.
FIG. 5 is a configuration diagram showing an example of a digitized duplex control device of a conventional standby redundancy system shown in Japanese Patent Laid-Open No. 5 (1994), in which reference numeral 1 denotes an arithmetic process for controlling a plant equipment system 50. An A control system (hereinafter abbreviated as A system) CPU unit 2 which has a self-diagnosis function of a failure and a B control system which has a self-diagnosis function of a failure while performing arithmetic processing for controlling the plant equipment system 50. A CPU unit (hereinafter abbreviated as B system) 3 makes a determination when one of the A system CPU unit 1 and the B system CPU unit 2 is a control system and the other is a standby system, and a control according to this determination. Dual system switching device for switching the system, 4 is a signal line for transmitting the A system control signal output from the dual system switching device 3 to the A system CPU section 1, and 5 is the A system C
A signal line for transmitting an A-system fault signal detected by the self-diagnosis in the PU unit 1 to the dual system switching device 3, and 6 is a duplicate of the B-system fault signal detected by the self-diagnosis in the B-system CPU unit 2. A signal line for transmitting to the system switching device 3, 7 is a signal line for transmitting a B system control signal output from the dual system switching device 3 to the B system CPU unit 2, and 31 is provided on the front surface of the dual system switching device 3. Given A
A system control selection switch, 32 is a B system control selection switch provided on the front surface of the dual system switching device 3, 33 is a system switching logic circuit incorporated in the dual system switching device 3, and 8 is a plant equipment system 50. An A system input / output unit for inputting / outputting control data to / from the A system CPU unit 1, a 9 B system input / output unit for inputting / outputting control data for the plant equipment system 50 to the B system CPU unit 2, and a 10 A system CPU unit 1 A system data transmission line that connects the A system input / output unit 8 to the A system data transmission line 11, a B system data transmission line that connects the B system CPU unit 2 and the B system input / output unit 9, and 50 represents the A system CPU unit 1 or the B system CPU It is a plant equipment system controlled by the unit 2.

Next, the operation will be described. Now, it is assumed that the system switching logic circuit 33 of the dual system switching device 3 switches the A system CPU section 1 to the control state and the B system CPU section 2 to the standby state. Therefore, the system switching logic circuit 33 outputs the A system control signal to the A system CPU section 1 through the signal line 4. In this state, when the A system CPU unit 1 detects an abnormality of itself or the A system input / output unit 8 by self-diagnosis, an A system failure signal is sent through the signal line 5 to the system switching logic circuit 33 of the dual system switching device 3. Output to.

When the system switching logic circuit 33 receives the A system failure signal, it confirms that the B system failure signal is not being input from the B system CPU section 2 through the signal line 6 at this time, and then through the signal line 4. The output of the A system control signal output to the CPU unit 1 is stopped, and the B system control signal is output to the B system CPU unit 2 through the signal line 7 instead. A system CPU section 1
When the input of the A-system control signal is stopped, the control processing of the plant equipment system 50 goes into a standby state, and conversely, B
When the B system control signal is input, the system CPU unit 2 performs a process of bringing the plant device system 50 into the control state and starts controlling the plant device system 50.

Next, when the B system CPU unit 2 is in the control state and the A system CPU unit 1 is in the standby state, if a failure occurs in the B system CPU unit 2 or the B system input / output unit 9, etc., On the contrary, the system switching logic 33 stops the output of the B system control signal output to the B system CPU section 2 through the signal line 7 and outputs the A system control signal to the A system CPU section 1 through the signal line 4. , The B system CPU section 2 is switched to the standby state and the A system CPU section 1 is switched to the control state.

The above is the case of automatically switching the system, but in addition to this, it has a function of manually selecting the control system. Now, the A system control and the B system standby state are set. If you want to change from this state to A system standby, B system control state,
The operator turns on the B system control selection switch 32 provided on the front surface of the dual system switching device 3. When the system switching logic circuit 33 inputs the closing signal of the B system control selection switch 32, after confirming that the B system CPU 2 does not input the B system failure signal, the system switching logic circuit 33 sends the A system C through the control signal line 4.
The output of the A system control signal output to the PU unit 1 is stopped, and the B system control signal is output to the B system CPU unit 2 through the signal line 7. If the operator turns on the A system control selection switch 31 in the B system control and A system standby state, the system switching logic circuit 33, conversely, stops outputting the B system control signal to the B system CPU section 2. , A-system control signal is output to the A-system CPU unit 1 to put the B-system on standby and the A-system in a controlled state.

[0007]

Since the conventional redundant control system of the redundant control system is constructed as described above, special hardware called the dual system switching device 3 for making the system switching judgment is required. Therefore, there is a problem in that the number of constituent elements of the device increases and the reliability and space of the device deteriorate, and even if a single failure of the input / output unit 8 or 9 occurs, the CPU
There has been a problem that switching of the entire system including the unit 1 or 2 occurs and the CPU unit cannot be operated efficiently.

The present invention has been made in order to solve the above-mentioned problems, and by implementing the switching of the control system by software, a special hardware device can be eliminated, and a single input / output unit can be provided. An object of the present invention is to obtain a dual system control device that does not require switching of the entire control system by switching only the corresponding input / output unit to the input / output unit of another control system when a failure occurs.

[0009]

According to a first aspect of the present invention, there is provided a duplex control device, which comprises a signal communication means for transmitting and receiving a signal between a first control system and a second control system via a signal line, and the self-controlling means. When the diagnostic function detects an abnormality of the self-control system, the abnormality communication signal is transmitted to the other control system by the signal communication means, and at this time, the self-control system is in the control state and the abnormality of the other control system by the signal communication means. If a signal indicating that the control system is not received, the control means determines that the self-control system is placed in the standby state, and the control means controls the other control system when the determination means determines that the self-control system is placed in the standby state. The control signal is transmitted from the signal communication means and the self control system is switched to the standby system, and when the switch signal from another control system is received through the signal communication means, the self control system is controlled. Control to switch to Wherein the Cormorant switching means first, but with both of the second control system.

According to a second aspect of the present invention, there is provided the duplex control device, wherein the first and second control systems are provided with input / output means belonging to each system with respect to the controlled object, and the first and second control systems are provided. When the control system of No. 2 controls the control target by exchanging data with the control target through these input / output means, the self-diagnosis function detects an abnormality only in the input / output means of the self-control system. At this time, the judging means switches the input / output of the data to the input / output means of the other control system so that the control state of the own control system is continued.

A duplexing control device according to a third aspect of the present invention is provided with a system changeover switch for requesting the self control system to switch to either one of a control state and a standby state. When the switch is turned on, the judging means transmits a switching request signal to the other control system by the signal communication means and judges to switch the state of the self-control system, and the switching means follows the judgment to determine the state of the self-control system. On the other hand, the switching means of the other control system switches the state of its own control system when receiving the switching request signal.

According to a fourth aspect of the present invention, in the duplex control device, the signal communication means includes the first and second signals through an isolation circuit that electrically insulates the signal from the input side and the output side. It is designed to transmit and receive between control systems.

In the duplex control device according to the invention of claim 5, the signal communication means sends one type of signal to two signal lines at the same time, so that the first and second control systems are connected to each other. It is designed to send and receive.

According to a sixth aspect of the present invention, in the duplex control device, the signal communication means receives the signal from another control system only when the two signals on the two signal lines match. It is intended to receive.

According to a seventh aspect of the present invention, in the duplex control device, the signal communication means makes the polarities of one signal in opposite phase when transmitting the signal to another control system, on the two signal lines. When the signals are sent to the other control system and the polarities of the two signals on the two signal lines are opposite to each other, the signals are received.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. FIG. 1 shows a second embodiment of the present invention.
FIG. 1 is a configuration diagram showing a duplexing control device, in which 12 is an A control system (hereinafter abbreviated as A system) CPU that performs arithmetic processing for controlling a plant equipment system 50 and has a self-diagnosis function of a failure. Section (first control system) determines the control status of the duplicated control system and switches the control status of the self-control system to the system switching function 121 and A system control selection for manually setting the A system. It has a switch (system changeover switch) 122. Reference numeral 13 denotes a B control system (hereinafter abbreviated as B system) CPU unit (second control system) which performs arithmetic processing for controlling the plant equipment system 50 and has a self-diagnosis function of a failure.
Then, a system switching function 131 that determines the control state of the duplicated control system and switches the control state of the self-control system, and a B system control selection switch (system changeover switch) 132 that manually controls the B system. Have Reference numeral 14 denotes an A system input / output unit (input / output unit) for inputting / outputting control data for the plant equipment system 50 to / from the A system CPU unit 12, and 15 denotes B for inputting / outputting control data for the plant equipment system 50 to the B system CPU unit 13. A system input / output unit (input / output means) 16 outputs an A system failure signal output from the system switching function 121 of the A system CPU unit 12 to a B system CP.
The signal line 17 is transmitted to the system switching function 131 of the U unit 13, and 17 is the B output from the system switching function 131 of the B system CPU unit 13.
A signal line for transmitting a system failure signal to the system switching function 121 of the A system CPU unit 12, and 18 is a system switching function 1 of the A system CPU unit 12.
The A system switching request signal output from 21 is transmitted to the B system CPU unit 1
3 is a signal line transmitted to the system switching function 131 of 3, and 19 is a B system C
A signal line for transmitting the B system switching request signal output from the system switching function 131 of the PU unit 13 to the system switching function 121 of the A system CPU unit 12, and 20 is the system switching function 12 of the A system CPU unit 12.
The A system switching permission signal output from 1 is transmitted to the B system CPU unit 13
Signal line for transmitting to the system switching function 131 of the
A signal line for transmitting a B system switching permission signal output from the system switching function 131 of the U unit 13 to the system switching function 121 of the A system CPU unit 12, and 22 is a system switching function 121 of the A system CPU unit 12.
A signal line for transmitting the A system controlling signal output from the B system CPU section 13 to the system switching function 131, and 23 denotes the B system controlling signal output from the B system CPU section 13 system switching function 131. A signal line transmitted to the system switching function 121 of the CPU unit 12, 24a is an A system data transmission line connecting the A system CPU unit 12 and the A system input / output unit 14, and 24b is an A system CPU unit 1.
2 and the B-system input / output unit 15 for connecting the A-system data transmission line, 25a for connecting the B-system CPU unit 13 and the B-system input / output unit 15 for the B-system data transmission line, and 25b for the B-system CPU unit 1
B system data transmission line connecting 3 and the A system input / output unit 14, 50 is a plant equipment system controlled by the A system CPU unit 12 or the B system CPU unit 121, and 121 is the state of the A system in a control state or a standby state. System switching function for switching to A, 122 is an A system control selection switch for manually controlling the A system, 128 is a self-diagnosis function for self-diagnosing and detecting an abnormality of the A system, and 131 is for controlling the state of the B system. A system switching function for switching the system to a standby state or a standby state, 132 is a B system control selection switch for manually controlling the B system, and 138 is a self-diagnosis function for self-diagnosing and detecting an abnormality of the B system. The system switching functions 121 and 131 described above are provided for each CPU.
It is assumed that the program is configured to run on the units 12 and 13.

FIG. 2 shows the system switching functions 121 and 1 shown in FIG.
FIG. 31 is a configuration diagram showing the details of 31, in which 121
Reference numeral 1 is a signal communication means for transmitting and receiving various control signals for system switching to and from another control system (system switching function 131), 12
Reference numeral 12 is a judging means for judging whether to switch the state of the self-control system from the state of the self-control system and the state of another control system, 121
Reference numeral 3 denotes switching means for switching the state of the self-control system according to the determination result of the determination means 1212, reference numeral 1311 denotes signal communication means for transmitting / receiving various control signals for system switching to / from another control system (system switching function 121), 1312. Is a judging means for judging whether to switch the status of the self-control system from the status of the self-control system and the status of the other control system, and 1313 is a judgment means 1312.
It is a switching means for switching the state of the self-control system according to the result of the judgment.

Next, the operation will be described. 3 is a flowchart showing the system switching control operation of the A system CPU unit 12 when the A system is in the control state, and FIG. 4 is the system of the B system CPU unit 13 when the B system is in the standby state. 6 is a flowchart showing a switching control operation, in which an A system control and a B system standby state are set. At this time, the system switching function 12 of the A system CPU unit 12
The switching means 1213 of No. 1 is A by the signal communication means 1211.
The system control signal is transmitted to the determination unit 1312 through the signal communication unit 1311 of the system switching function 131 of the B system CPU unit 13. The A system CPU unit 12 controls the plant device system 50 by transmitting and receiving control data to and from the plant device system 50 via the A system input / output unit 14 (step ST301 in FIG. 3). In this state, when the A-system self-diagnosis function 128 detects an abnormality in the A-system (step ST30
2), the judgment means 1212 of the system switching function 121
The signal communication means 1211 transmits an A system failure signal to the B system determination means 1312, and analyzes the content of this abnormality to determine whether or not only the A system input / output unit 14 is abnormal (step ST303). As a result, the A system input / output unit 14
If it is not abnormal, the judging means 1212 confirms that the B system failure signal indicating the abnormality of the B system is not input from the judging means 1312 of the other control system, that is, the B system (step ST304). It is determined that the control system should be switched to the standby system (step ST305), and the switching means 1213 is notified of the determination result. In step ST304, if the B system failure signal is input,
The judging means 1212 ends the process.

When the A-system switching means 1213 receives the determination result, it stops the transmission of the A-system controlling signal which has been transmitted from the signal communication means 1211 to the B-system determining means 1312 (step ST306). System input / output unit 14 or B
The access to the system input / output unit 15 is stopped to switch the control system from the control system to the standby system (step ST30
7), signal communication means 1211 to B-system determination means 131
2 transmits an A-system switching permission signal (step ST30)
8).

On the other hand, the B system CPU section 13 is initially in a standby state with respect to the plant equipment system 50 (step ST401 in FIG. 4). After that, the judgment means 1312 of B system is A
When the A system switching permission signal is received from the system switching means 1213 (step ST402), it is judged that the self control system is switched to the standby system (step ST403), and this is given to the switching means 1313. The switching means 1313 switches its own control system from the standby system to the control system according to the above judgment (step ST404), and at the same time transmits the B system control signal to the judgment means 1212 of the A system by the signal communication means 1311 (step ST405). Through the series of operations described above, the A system CPU unit 12 shifts to the standby state, the B system CPU unit 13 shifts to the control state instead, and the B system input / output unit 15 is used to communicate with the plant equipment system 50. The control of the plant equipment system 50 is started by transmitting and receiving the control data at.

By the way, the A system self-diagnosis function 128 is
When a system abnormality is detected (step ST30 in FIG. 3)
2), the judgment means 1212 analyzes the content of this abnormality,
When it is determined that the abnormality is only the A system input / output unit 14 (step ST303), the determination means 1212 immediately determines to switch the input / output unit to be used to the B system input / output unit 15 (step ST309). This is the switching means 121
Notify 3. The switching means 1213 determines the A-system input / output unit 14 through the data transmission line 24a according to the determination result.
Access to the B system input / output unit 15 through the data transmission line 24b is switched (step ST310). After that, the A system CPU unit 12 continues control of the plant device system 50 by transmitting and receiving control data to and from the plant device system 50 via the B system input / output unit 15.

Contrary to the above, also in the A system standby and B system control states, the system switching function 131 of the B system CPU section 13 puts the B system in the standby state in the same manner as described above, and at the same time, the A system CP.
The system switching function 121 of the U unit 12 puts the A system in a controlled state.

Next, the operation of manually switching the control system will be described. Now, the A system control and the B system standby state are set.
At this time, the B system control selection switch 13 of the B system CPU section 13
It is assumed that 2 is input by the operator. The determination means 1312 of the system switching function 131 of the B system, which has received this input signal, transmits the B system switching request signal to the switching means 1213 of the system switching function 121 of the A system by the signal communication means 1311. When the A-system switching means 1213 receives the B-system switching request signal from the signal communication means 1311, the A-system switching means 1213 outputs the B-system switching request signal B to the B-system switching means 1211.
After stopping the transmission of the A-system controlling signal which has been transmitted to the system determining means 1312, the access to the A-system input / output unit 14 or the B-system input / output unit 15 is stopped and the self-control system is changed from the control system to the standby system. At the same time, the signal communication means 1211 transmits an A system switching permission signal to the B system judging means 1312.

Upon receiving the A-system switching permission signal, the B-system judging means 1312 judges to switch the self-control system to the control system, and gives this to the switching means 1313. Switching means 13
In accordance with the above determination, 13 switches the self control system from the standby system to the control system, and at the same time transmits the B system control signal to the A system determination means 1212 by the signal communication means 1311. Or later,
The B system CPU unit 13 shifts to the control system, and the B system input / output unit 15
The control of the plant equipment system 50 is started by transmitting and receiving the control data to and from the plant equipment system 50 via.

Contrary to the above, in the case of the A system standby and B system control states, the A system control selection switch 1 of the A system CPU section 12
If 22 is turned on, the A system CPU unit 12 is in the control state and the B system CPU unit 13 is in the standby state.

According to this embodiment, the A system CPU section 12 and the B system C are arranged so as to judge the states of the self control system and the other control system, judge the control state of the self control system, and switch the states.
Since each of the PU units 13 is provided with the system switching function 121 and the system switching function 131 configured by software, the system switching can be performed by software, and a special hardware device for system switching can be reduced. It is possible to improve the reliability by reducing the number of component parts of the device, and by changing the system switching software described above, the specifications of the device can be easily changed,
The flexibility of the device can be improved. Further, when the A-system input / output unit 14 or the B-system input / output unit 15 has a single failure, only the corresponding input / output unit is switched to the input / output unit of another control system, thereby eliminating the need to switch the entire control system. Therefore, the A system CPU unit 12 or the B system CPU unit 13 can be efficiently operated.

Embodiment 2. FIG. 5 is a block diagram showing a duplexing control device according to Embodiment 2 of the present invention. However,
The same parts as those in the first embodiment are described using the same reference numerals. In the figure, reference numeral 123 denotes an isolation unit (isolation circuit) for performing input / output of signals for system switching in a state of being electrically insulated from the A system CPU unit 12.
133 is a B system CPU for inputting / outputting signals for system switching.
This is an isolation unit (isolation circuit) for performing the operation while being electrically insulated from the unit 13. The other parts are the same as those in the first embodiment and have the same configuration, so the description thereof will be omitted.

Next, the operation will be described. The isolation unit 123 uses, for example, a photocoupler (not shown) or the like to electrically insulate the A-system CPU unit 12 when the above-mentioned signal for system switching is input / output.
That is, the system switching function 121 of the A system CPU unit 12 is, for example, A
When the system switching permission signal is output to the isolation unit 123, the isolation unit 123 outputs the input A system switching permission signal to the signal line 20 via the photo coupler. The A-system switching permission signal transmitted on the signal line 20 is input to the isolation unit 133 of the B-system CPU unit 13, where the system switching function 1 is provided via a photo coupler.
It is input to 31. Isolation section 123, 133
Since the photo coupler of (1) once converts an electric signal into an optical signal and then converts it into an electric signal again, the signal input side and the signal output side are electrically insulated at this portion. The same applies to other signals, and the isolation units 123 and 133 electrically insulate the signal input side and the signal output side.
The operation of the isolation unit during transmission of other signals is the same. Further, other operations are the same as those in the previous embodiment, and the description thereof will be omitted.

According to this embodiment, the A system CPU unit 1
Since the signal for system switching transmitted / received between the No. 2 and the B system CPU unit 13 is input / output in an electrically insulated state, the disturbance in one control system does not affect the other control system. Thus, the reliability of the device can be improved as compared with the previous embodiment. Other effects are similar to those of the previous embodiment.

Embodiment 3 6 is a block diagram showing a duplexing control device according to Embodiment 3 of the present invention. However,
The same parts as those in the second embodiment are described using the same reference numerals. In the figure, 16p and 16q are the A system failure signals output from the system switching function 121 of the A system CPU unit 12 and the B system C.
Duplicated signal line for transmitting to the PU unit 13, 17p, 1
7q is a dual signal line for transmitting a B system failure signal output from the system switching function 131 of the B system CPU unit 13 to the A system CPU unit 12, and 18p and 18q are system switching functions of the A system CPU unit 12. Duplicated signal lines 19p and 19q for transmitting the A system switching request signal output from 121 to the system switching function 131 of the B system CPU section 13 are output from the system switching function 131 of the B system CPU section 13. B system switching request signal for A system CP
The duplicated signal lines for transmitting to the system switching function 121 of the U unit 12, 20p and 20q are A system switching permission signals output from the system switching function 121 of the A system CPU unit 12, and are connected to the system of the B system CPU unit 13. Dual signal lines 21p and 21q for transmission to the switching function 131 are the system switching functions 1 of the B system CPU unit 13.
The B system switching permission signal output from the A system 31 is sent to the A system CPU unit 1
A dual signal line for transmission to the system switching function 121
22p and 22q are system switching functions 121 of the A system CPU unit 12.
A duplexed signal line for transmitting the A-system control signal output from the system to the system switching function 131 of the B-system CPU unit 13, 23
p and 23q are duplicated signal lines for transmitting the B system control signal output from the system switching function 131 of the B system CPU unit 13 to the system switching function 121 of the A system CPU unit 12, and 124 is a signal line 17p. , A matching circuit that inputs this signal only when the signals on 17q match, 125 is a matching circuit that inputs this signal only when both signals on signal lines 19p and 19q match, 126 is a signal line 21p and 21q A matching circuit that inputs this signal only when both signals match, 127 is a matching circuit that inputs this signal only when both signals on the signal lines 23p and 23q match, and 134 is a matching circuit that inputs both signals on the signal lines 16p and 16q Matching circuit that inputs this signal only when the signals match,
135 is a matching circuit that inputs this signal only when both signals on the signal lines 18p and 18q match, 136 is the signal line 20
A matching circuit 137 that inputs this signal only when both signals on p and 20q match is a matching circuit that inputs this signal only when the signals on signal lines 22p and 22q match.
The other parts are the same as those in the second embodiment and have the same configuration, so the description thereof will be omitted.

FIG. 7 is a circuit diagram showing details of the above-mentioned matching circuit. In the figure, 71 is an exclusive OR circuit that takes an exclusive OR of two input signals, and 72 is a gate circuit that opens / closes the circuit to output / stop the input signal.

Next, the operation will be described. The system switching function 121 of the A system CPU unit 12 transmits, for example, an A system switching permission signal to the B system CPU unit 13 through the signal lines 20p and 20q. The matching circuit 136 of the B system CPU unit 13 inputs and outputs it to the system switching function 131 only when the duplicated A system switching permission signals transmitted through the two signal lines match. The same applies to the other signals, and the signals are transmitted to the CPU section of the other control system through the duplicated signal lines, and the two signals thus transmitted are used in the coincidence circuit only when the two signals coincide with each other. Entered in. Since the other operations are the same as those in the first and second embodiments, the description thereof will be omitted.

Here, the operation of the above-mentioned matching circuit will be described. In the figure, the exclusive OR circuit 71 becomes low level when the signal (1) and the signal (2) match in phase, and becomes high level when the signal (1) and the signal (2) do not match. The gate circuit 72 conducts and outputs the input signal (1) only when a low level signal is input from the exclusive OR circuit 71. Therefore, the signal (1) is applied to the gate circuit 7 only when the polarities of the signal (1) and the signal (2) are the same.
It will be output from 2. The signal (1) and the signal (2) are one and the other of the above-mentioned doubled signals.

According to this embodiment, the A system CPU unit 1
The signal for switching the control system is mutually transmitted between the 2 and the B system CPU unit 13 by the duplicated signal line, and at the time of input, it is input only when the signals on both signal lines match. Therefore, it is possible to prevent the switching of the control system from being disabled due to the interruption of the signal for switching one system, and it is possible to further improve the reliability of the device as compared with the second embodiment. Other effects are similar to those of the previous embodiment. The configuration for transmitting the signal for system switching by the duplicated signal line can be applied to the device without the isolation part as shown in FIG. 1, and the same effect can be obtained. .

Embodiment 4 FIG. FIG. 8 is a configuration diagram showing a duplexing control device according to Embodiment 4 of the present invention. However,
The same parts as those in the third embodiment are described using the same reference numerals. In the figure, reference numeral 151 denotes an inverting output circuit that inverts the polarity of one signal when outputting the A system failure signal to the duplicated signal lines 16p and 16q, and 152 has the A system switching request signal duplicated. An inverting output circuit for inverting the polarity of one signal when outputting to the signal lines 18p and 18q, and 153, a polarity of one signal when outputting the A system switching permission signal to the duplicated signal lines 20p and 20q. Inversion output circuit for inverting
Reference numeral 54 is a signal line 22p, 2p in which an A system control signal is duplicated.
An inverting output circuit for inverting the polarity of one signal when outputting to 2q, 155 is a B system failure only when the polarities of the two B system failure signals on the duplicated signal lines 17p and 17q are opposite phases. An inverting input circuit for inputting a signal, 156 is an inverting input circuit for inputting a B system switching request signal only when the polarities of the two B system switching request signals on the duplicated signal lines 19p and 19q are opposite phases, Reference numeral 157 denotes 2 on the duplicated signal lines 21p and 21q.
An inverting input circuit 158 for inputting the B system switching permission signal only when the polarities of the B system switching permission signals are in opposite phases, and 158 denotes two B system control signals on the duplicated signal lines 23p and 23q. This is an inverting input circuit that inputs the B system control signal only when the polarities are opposite phases.

Further, 161 is a duplicated signal line 16
An inverting input circuit for inputting the A-system fault signal only when the polarities of the two A-system fault signals on p and 16q are opposite phases, and 162 is the two A-system fault signals on the duplicated signal lines 18p and 18q. An inverting input circuit for inputting the A-system switching request signal only when the polarities of the switching request signals are opposite phases, and 163 is a duplicated signal line 20p, 2
An inverting input circuit for inputting the A-system switching permission signals only when the polarities of the two A-system switching permission signals on 0q are in opposite phases, and 164 is 2
An inverting input circuit for inputting the A system controlling signal only when the polarities of the two A system controlling signals on the duplicated signal lines 22p and 22q are opposite phases, and 165 is a duplicate of the B system failure signal. An inverting output circuit 166 that inverts the polarity of one of the signals when the signal is output to the signal lines 17p and 17q is output from one of the signals when the B system switching request signal is output to the duplicated signal lines 19p and 19q. An inverting output circuit that inverts the polarity, 167 is an inverting output circuit that inverts the polarity of one of the signals when outputting the B system switching permission signal to the duplicated signal lines 21p and 21q, 168.
Is a signal line 23p, 23q in which the B system control signal is duplicated.
It is an inverting output circuit that inverts the polarity of one of the signals when it is output to. The other parts are the same as those in the second embodiment and have the same configuration, so the description thereof will be omitted.

FIG. 9 is a circuit diagram showing details of the above-mentioned inverting output circuit. In the figure, reference numeral 91 is a polarity inverting circuit for inverting the polarity of the input signal.

FIG. 10 is a circuit diagram showing the details of the above inverting input circuit. In the figure, 101 is input 2
A negation exclusive OR circuit that takes the exclusive OR of the signals and outputs the negation of the result, and 102 is a gate circuit that opens / closes the circuit to stop the output / output of the input signal.

Next, the operation will be described. When the system switching function 121 of the A system CPU unit 12 transmits, for example, the A system switching permission signal to the B system CPU unit 13 through the signal lines 20p and 20q, the inverting output circuit 153 causes the inversion output circuit 153 to keep the A system switching permission signal in phase. Simultaneously with the output on 20p, the polarity of the A system switching permission signal is inverted by the polarity inversion circuit 91 (see FIG. 9) and output on the signal line 20q. The inverting input circuit 163 of the B system CPU unit 13 inputs the A system switching permission signal and outputs it to the system switching function 131 only when the A system switching permission signals on the signal line 20p and the signal line 20q are in opposite phases. . The same applies to other signals. The polarity of one signal is inverted by the inverting output circuit, and the signal is transmitted to the CPU section of the other control system through the duplicated signal line.
The signal is input to the system switching function of the other system by the inverting input circuit only when the polarities of both signals are opposite to each other. Since the other operations are the same as those in the first and second embodiments, the description thereof will be omitted.

Now, the operation of the above-mentioned inverting input circuit will be described. In FIG. 10, the output of the exclusive-NOR circuit 101 becomes low level when the polarities of the signal (1) and the signal (2) are opposite to each other, and when the signals (1) and (2) are in the same phase. High level. Gate circuit 10
2 outputs a signal (1) which is conductive and is input only when a low level signal is input from the exclusive NOR circuit 101. Therefore, the signal (1) is output from the gate circuit 102 only when the polarities of the signal (1) and the signal (2) are opposite to each other. The signal (1) and the signal (2) are one and the other of the above-mentioned doubled signals.

According to this embodiment, when the connection cable is broken, the duplicated signals input to the inverting input circuit are in phase, so this signal is input to the system switching function of the CPU section. Therefore, it is possible to prevent unnecessary system switching from occurring in the event of an abnormality. Similarly, other control systems,
It is possible to prevent erroneous switching of the system even when the self-control system or the connection cable is abnormal, and further improve the reliability of the device. Other effects are similar to those of the previous embodiment.

[0042]

As described above, according to the first aspect of the present invention, each of the duplicated control systems is provided with a system switching function constituted by software, and these system switching functions are used for switching the control systems. Are configured to send and receive signals to and from each other to switch the state of the control system, so that it is possible to reduce the number of hardware devices for system switching, reduce the number of component parts of the device, and improve its reliability. At the same time, the specifications of the system switching function can be easily changed to improve the flexibility of the device.

According to the second aspect of the present invention, when only the input / output device of the self control system is abnormal, only this input / output device is switched to the input / output device of another control system. In the case of a single failure, it is not necessary to switch the entire control system, and the control system can be operated efficiently.

According to the third aspect of the present invention, each control system is provided with a system changeover switch, and when this system changeover switch is pressed, the system changeover function of each control system changes the state of its own control system. Also, the state of the control system can be switched by the manual operation of the operator.

According to the invention of claim 4, when the control system transmits / receives a signal for switching the control system to / from another control system, the control system is electrically insulated. Therefore, it is possible to prevent the disturbance in the other control system from spreading to the own control system, and to improve the stability of the control system.

According to the fifth aspect of the present invention, the signal for switching the control system is duplicated and transmitted / received to / from another control system, so that the switching of the control system due to the interruption of one signal is prevented. Thus, there is an effect of improving the reliability of the device.

According to the sixth aspect of the present invention, since the signal transmitted from the other control system is received only when the duplicated signals coincide with each other, an error in the control system due to an abnormal signal occurs. This has the effect of preventing switching and further improving the reliability of the device.

According to the invention of claim 7, the signals are transmitted so that the polarities of the doubled signals are opposite to each other, and
Since the signal transmitted from another control system is received only when the polarities of the duplicated signals are opposite to each other, erroneous switching of the control system due to the occurrence of an abnormality in the control system or the signal transmission system can be prevented. This can be prevented more completely, and has the effect of further improving the reliability of the device.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a duplexing control device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a detailed example of a system switching function shown in FIG.

FIG. 3 is a flowchart showing an example of a system switching operation according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing an example of a system switching operation according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram showing a duplexing control device according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram showing a duplexing control device according to a third embodiment of the present invention.

FIG. 7 is a circuit diagram showing a detailed example of the matching circuit shown in FIG.

FIG. 8 is a configuration diagram showing a duplexing control device according to Embodiment 4 of the present invention.

9 is a circuit diagram showing a detailed example of the inverting output circuit shown in FIG.

10 is a circuit diagram showing a detailed example of the inverting input circuit shown in FIG.

FIG. 11 is a configuration diagram showing an example of a conventional duplex control device.

[Explanation of symbols]

12 A system CPU section (first control system), 13 B system CP
U unit (second control system), 14 A system input / output unit (input / output unit), 15 B system input / output unit (input / output unit), 16 to 23
Signal line, 122 A system control selection switch (system changeover switch), 123, 133 Isolation unit (isolation circuit), 128, 138 Self-diagnosis function, 1
32 B system control selection switch (system selection switch), 12
11, 1311 signal communication means, 1212, 1312
Judgment means, 1213, 1313 switching means.

Claims (7)

[Claims] 1. When one of the controlled objects is in a controlled state,
In the duplex control device having the first and second control systems in which the other is in a standby state, and these first and second control systems each have a self-diagnosis function for detecting an abnormality in the self-control system, When the self-diagnosis function detects an abnormality in the self-control system, a signal communication means for transmitting and receiving a signal between the first and second control systems via a signal line, and another abnormality control signal is controlled by the signal communication means. At the same time as transmitting to the system, when the self control system is in the control state and the signal indicating the abnormality of the other control system is not received by the signal communication means, the control to make the self control system in the standby state is performed. When the determining means performs the determination and the determination means determines that the self control system is in the standby state, a control signal for transmitting the switching signal for setting the other control system in the control state by the signal communication means and switching the self control system to the standby system And the signal communication means Both of the first and second control systems are provided with switching means for performing control to switch the self-control system to the control state when the switching signal from the other control system is received through the control system. Duplex controller. 2. The first and second control systems are provided with input / output means belonging to each system with respect to the controlled object, and the first and second control systems receive data through these input / output means. When controlling the controlled object by exchanging with the controlled object, when the self-diagnosis function detects an abnormality in only the input / output means of the self-control system, the judging means determines the input / output of the data. 2. The duplex control device according to claim 1, wherein the control state of the own control system is continued by switching the input and output means of another control system. 3. A system changeover switch for requesting the self-control system to switch to either one of a control state and a standby state, and when the system changeover switch is turned on, the judging means makes signal communication. By means of transmitting a switching request signal to another system by means, it is determined to switch the state of the self-control system,
3. The switching means switches the state of its own control system according to this judgment, while the switching means of another system switches the state of its own control system when it receives the switching request signal. Dual control device. 4. The signal communication means transmits / receives the signal between the first and second control systems via an isolation circuit that electrically insulates the input side and the output side. The duplex control device according to any one of claims 1 to 3. 5. The signal communication means performs transmission / reception between the first and second control systems by simultaneously transmitting one type of signal to two signal lines. The duplexing control device according to claim 4. 6. The signal communication means receives the signal only when both signals on the two signal lines match when receiving the signal from another control system.
The duplex control device described. 7. The signal communication means, when transmitting the signal to another control system, makes the polarities of one signal opposite to each other and sends the signals to the two signal lines, and the signal is transmitted from the other control system. 6. The duplexing control device according to claim 5, wherein the signals are received only when the polarities of the two signals on the two signal lines are opposite to each other when receiving the signals.