JPH09325811A - Duplex redundant system and diagnostic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately diagnose the state of transmission line regardless of the operating state of its own device and a device of the opposite party, by outputting a signal to a 1st transmission line to show the operating state and the diagnostic operation of its own device and accordingly receiving a signal returned via a 2nd return line to confirm the diagnostic operation of the device of the opposite party. SOLUTION: Both controllers 1 and 2 have the same constitution and are operated in parallel to each other as the working and stand-by sides respectively. A signal transmission part of the controller 1 is composed of a status signal output circuit 11, a normal mode diagnostic signal output circuit 12 and an abnormal mode diagnostic signal output circuit 13. Then a signal reception part of the controller 1 is composed of a status signal reception circuit 14, an abnormal mode diagnostic signal reception circuit 15 and a normal mode diagnostic signal reception circuit 16. The signals showing the operating state and the diagnostic operation of the controller 1 are outputted to a 1st transmission line 3 from the signal transmission part. Accordingly, the signals returned from the controller 2 of the opposite party side via a 2nd transmission line 4 are received at the signal reception part to confirm the diagnostic operation of the controller 2. Thus, both transmission lines 3 and 4 are diagnosed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual redundant system and a diagnostic method, and more particularly to a dual redundant system and a diagnostic method in which an operating side and a standby side monitor operating states of the other side.

[0002]

2. Description of the Related Art Generally, in a dual redundant system which realizes redundancy by operating two control devices on the operating side and the standby side in parallel, a predetermined status signal (state signal) output from the other side. It constantly monitors the operating state of the other side, and when an abnormality occurs on the operating side in particular, it detects it on the standby side and performs a switching operation so that the standby side operates as a new operating side. ing.

Conventionally, as this kind of status signal,
In order to notify the normal / abnormal distinction, for example, it has a binary value of “H level” indicating a normal state and “L level” indicating that an abnormality has occurred, and these two values are set according to the own operating state.
One of the values was selected and sent to the other party.

[0004]

However, in such a conventional duplex redundancy system, since the status signal for notifying the other party of its own operation state has only a binary level, the status signal is When the transmission line for transmitting the is disconnected, it is judged as normal or abnormal. Especially in field devices installed outdoors, the operating side and the standby side are often installed in physically separate places, and the failure rates in the disconnection mode of the transmission line that exchanges status signals between them are compared. It tends to be extremely high, which is a factor that disturbs the control by the redundant redundancy system. The present invention is intended to solve such a problem, and provides a duplicated redundancy system and a diagnostic method capable of accurately diagnosing the state of a transmission path for transmitting a status signal and obtaining higher reliability. It is an object.

[0005]

In order to achieve such an object, a redundant redundancy system and a diagnostic method according to the present invention indicate the operating state of its own device, that is, normal / abnormal, and indicate the start / end of diagnosis. A signal transmission unit that outputs a signal to the partner device via the first transmission path and a signal received from the partner device via the second transmission path to detect the operating state of the partner device and to perform diagnostic operation. When diagnosing the signal reception unit that detects the start and end and the first and second transmission lines, the signal transmission unit outputs a signal indicating the operating state and the diagnostic operation of the own device to the first transmission line, In response to this, the signal receiving unit receives the signal returned from the partner device via the second transmission path and confirms the diagnostic operation of the partner device, thereby diagnosing the first and second transmission paths. With a control unit A. In addition, the signal transmission unit outputs a status signal output circuit that outputs a status signal that indicates the operating state of the device itself, and a normal-time diagnostic signal output that outputs a diagnostic signal that indicates the start / end of diagnostic operation when the device itself is in a normal state. A circuit and an abnormal-time diagnostic signal output circuit that outputs a diagnostic signal when the device itself is in an abnormal state, and the signal receiving unit detects the status signal indicating the operating state of the partner device; A normal-time diagnostic signal receiving circuit for receiving a normal-time diagnostic signal and an abnormal-time diagnostic signal receiving circuit for receiving an abnormal diagnostic signal are provided. Therefore, the signal indicating the operating state and the diagnostic operation of the own device is output to the partner device via the first transmission path, and the signal returned from the partner device via the second transmission path in response to the signal is output. Upon reception, the diagnostic operation of the partner device is confirmed, and the first and second transmission paths are diagnosed.

[0006]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a duplicated redundancy system which is an embodiment of the present invention. In FIG.
(2) is a control device that outputs a predetermined control signal to each device such as process equipment in response to an instruction from a higher-level device, and 3 is a control device 2 that outputs a status signal indicating the operating state of the control device 1.
A transmission line (first transmission line) 4 for transmitting to the control device 1 and a transmission line (second transmission line) 4 for transmitting a status signal indicating the operating state of the control device 2 to the control device 1. The control devices 1 and 2 have the same configuration, and are operated in parallel as an operating side and a standby side.

In the controller 1 (2), 11 (21)
Is a transistor TS1 (TS2) and a load resistor RS1 (R
S2) and STTSD1 (STT) indicating the operating state.
SD2) A predetermined status signal is transmitted according to the signal to the transmission line 3
It is a status signal output circuit for outputting to (4). 12
(22) has a transistor TL1 (TL2) and an AND gate AND12, and is predetermined when its own operating state is “normal” according to the STTSD1 (STTSD2) signal and the DIAG1 (DIAG2) signal indicating the start and end of diagnosis. It is a normal-time diagnostic signal output circuit for outputting the diagnostic signal of 1 to the transmission line 3 (4).

13 (23) is a transistor TH1 (TH
2), an AND gate AND13 (AND23), and a load resistor RH1, and STTSD1 (STTSD
2) DIAG1 indicating signal inversion logic and diagnosis start / end
It is an abnormal-time diagnostic signal output circuit that outputs a predetermined diagnostic signal to the transmission path 3 (4) when the operating state is "abnormal" according to the (DIAG2) signal. These are a status signal output circuit 11 (21) and a normal time diagnostic signal output circuit 12
(22) and the abnormality diagnosis output circuit 13 (23) constitute a signal transmission section.

Further, 14 (24) is a comparator CMP14.
(CMP24), receives the status signal from the transmission line 4 (3) based on the reference voltage VS1 (VS2), and outputs the STTSR1 (STTSR2) signal as the status signal indicating the operating state of the control circuit 2 (1). Status signal receiving circuit. 15 (25) is a comparator CMP1
5 (CMP25), and receives an abnormal time diagnostic signal from the transmission line 4 (3) based on the reference voltage VL1 (VL2),
It is an abnormal-time diagnostic signal receiving circuit that outputs a LOK1 (LOK2) signal indicating the diagnostic result.

Reference numeral 16 (26) is a comparator CMP16 (CMP
26), which receives a normal-time diagnostic signal from the transmission line 4 (3) based on the reference voltage VH1 (VH2) and outputs a HOK1 (HOK2) signal indicating the diagnostic result. is there. The status signal receiving circuit 14, the abnormal-time diagnostic signal receiving circuit 15, and the normal-time diagnostic signal receiving circuit 16 constitute a signal receiving unit.

RL1 (RL2) is a resistor for supplying a predetermined current from the power supply voltage Vcc to the control device 2 (1) side via the transmission line 4 (3). Reference numeral 10 (20) outputs a predetermined control signal to each device in response to an instruction from a host device (not shown) and, if necessary, STTSD.
1 (STTTSD2) signal is output to each part of the signal transmission unit to instruct the transmission of a predetermined status signal and diagnostic signal, and STTSSR1 (ST
TSR2) signal, LOK1 (LOK2) signal, and H
It is a control unit that diagnoses the operating state of the control device 2 (1) side and the states of the transmission lines 3 and 4 according to the OK1 (HOK2) signal, and performs switching control between the operating side and the standby side based on the result. .

The state signal receiving circuit 14 (24)
Reference voltage VS1 (VS2) is set to a predetermined value, for example, 1/2 of the power supply voltage Vcc, and the abnormal-time diagnostic signal receiving circuit 15 (25) and the normal-time diagnostic signal receiving circuit 1
6 (26) reference voltages VL1 (VL2) and VH1
(VH2) is a predetermined voltage between the reference voltage VS1 (VS2) and the power supply voltage Vcc, and the reference voltage VS1.
It is set to a predetermined voltage between (VS2) and the ground potential.

Therefore, when the controller 1 (2) is in the normal state (state 1), the transistor TS1 (T
Only S2) is “ON” and the VT2 (VT1) signal becomes a voltage between the reference voltage VS2 (VS1) and the reference voltage VH2 (VH1), and when the diagnostic operation is performed in this normal state (state 2) , And the transistor TL1 is "O
N ”so that the VT2 (VT1) signal drops to a voltage between the reference voltage VH2 and the ground potential.
L1) and RS1 (RS2) are set.

When the control device 1 (2) is in an abnormal state (state 3), all the transistors TS1,
TL1, TH1 (TS2, 2L2, TH2) is "OF
F ”, the VT2 (VT1) signal becomes higher than the reference voltage VS2 and becomes a voltage between the reference voltage VS2 (VS1) and the power supply voltage Vcc, and when the diagnostic operation is performed in this abnormal state (state 4), TH1 turns “ON” and V
RH1 (RH2) is set so that the T2 (VT1) signal drops to a voltage between the reference voltage VL2 (VL1) and the reference voltage VS2 (VS1).

Next, the operation of the present invention will be described with reference to FIGS. 2 and 3 as an example of a diagnostic processing operation when the control device 1 is in a normal state and the control device 2 is in an abnormal state. FIG.
FIG. 4 is an explanatory diagram showing states of respective signals and transistors when diagnosing the transmission lines 3 and 4 from the control device 1.
"H level" indicates normal, and "L level" indicates abnormal. In the case of diagnosing the transmission lines 3 and 4 from the control device 2, the control devices 1 and 2 are replaced with each other in FIG. FIG. 3 is a timing chart showing signals of respective parts of FIG.

In FIG. 2, the state 1 is the control device 1.
When the (transmission side) is in the normal state, State 2 is the diagnostic operation state when the control device 1 is in the normal state, State 3
Indicates a diagnostic operation state when the control device 1 is in an abnormal state, and state 4 indicates a diagnostic operation state when the control device 1 is in an abnormal state. Before time T1 in FIG. 3, the control unit 10 of the control device 1 is operating normally without detecting any abnormality in its own device, and is not performing the diagnostic operation.
"H level" is output as one signal, and "L level" is output as the DIAG signal.

In response to this, the state signal output circuit 11
Transistor TS1 of "ON", transistor TL
1 and TH1 are both “OFF”, and as a state signal indicating the operating state of the control device 1, the resistor RL2, the transmission line 3, and the resistor RS1 are supplied from the power supply Vcc on the control device 2 side.
A predetermined current flows through. In the control device 2, the voltage generated by this current is detected as a VT2 signal and received by each of the signal receiving circuits 24-26.

The status signal receiving circuit 24 has, for example, a voltage value reference voltage VS2 that is approximately 1/2 of the power supply voltage Vcc, and when the control device 1 is in the state 1, the time T in FIG.
1 as shown before, V which is lower than the reference voltage VS2
Since the T2 signal is input, the comparator CMP24 outputs the “H level” STTSR2 signal. Also,
The normal-time diagnostic signal receiving circuit 26 has a reference voltage VH2 provided between the reference voltage VS2 and the ground potential,
When the control device 1 is in the state 1, since the VT2 signal having a voltage higher than the reference voltage VH2 is input, the comparator C
The MP26 outputs the “L level” HOK2 signal.

The control unit 20 of the control device 2 uses the STTSR2
Since the signal is "H level", the normal state of the control device 1 is confirmed, and the HOK2 signal is "L level".
Therefore, it is confirmed that the control device 1 is not performing the diagnostic operation. Further, since the control device 2 detects an abnormality in its own device, it outputs the STSSD2 signal of "L level" as the state of state 3 to output the transistor TS2.
Is turned off, and since the diagnostic operation is not in progress, the DIAG2 signal of "L level" is output to turn off the transistors TL2 and TH2. This allows
Almost no current flows through the transmission line 4, and the VT of the control device 1
One signal has almost the power supply voltage Vcc before the time T1.

The status signal receiving circuit 14 has, for example, a voltage value reference voltage VS1 that is approximately ½ of the power supply voltage Vcc. When the control device 2 is in state 3, as shown before time T1 in FIG. Since the VT1 signal having a voltage higher than the reference voltage VS1 is input, the comparator CMP14 outputs the “L level” STTSR1 signal. Further, the abnormality diagnostic signal receiving circuit 15 has a reference voltage VL1 provided between the reference voltage VS1 and the power supply voltage, and when the control device 2 is in the state 3, the reference voltage VL1.
Since the VT1 signal having a higher voltage is input, the comparator CMP15 outputs the “L level” LOK1 signal.

The control unit 10 of the control device 1 uses the STTSR1
Since the signal is "L level", the abnormal state of the control device 2 is confirmed and the LOK1 signal is "L level".
Therefore, it is confirmed that the control device 2 is not performing the diagnostic operation. When the control unit 10 of the control device 1 performs the diagnosis of the transmission paths 3 and 4 autonomously or based on an instruction from the host device at the time T1 in such a state,
First, the DIAG1 signal is changed to "H level" to turn on the transistor TL1 and a normal state diagnostic signal is output together with the status signal (state 2).

In response to this, the voltage of the VT2 signal of the control device 2 becomes lower than the reference voltage VH2. The comparator CMP26 of the normal-time diagnostic signal receiving circuit 26 detects the decrease of the VT2 signal and changes the HOK2 signal to "H level",
Receives and outputs the diagnostic signal in normal condition. As a result, the control unit 20 confirms that the control device 1 is performing the diagnostic operation, changes the DIAG2 signal to "H level" in response, and turns on the transistor TH2 (state 4).

Therefore, the VT1 signal of the controller 1 drops to a voltage between the reference voltage VL1 and the reference voltage VS1. Comparator CMP15 of the diagnostic signal receiving circuit 15 at abnormal time
Detects the drop of the VT1 signal, changes the LOK1 signal to "H level", and receives and outputs a diagnostic signal at the time of abnormality. The control unit 10 starts the diagnostic operation of its own device, that is, the time T1 when the DIAG1 signal is changed to "H level".
From the time t until the LOK1 signal becomes "H level"
1 is detected, and when this time t1 is within the predetermined time, it is determined that the diagnostic signal output from the device itself has been normally received and returned by the control device 2, and the transmission lines 3 and 4 are normal. Confirm that there is.

When the "H level" LOK1 signal cannot be detected within a predetermined time from the output of the diagnostic signal, it is determined that there is an abnormality in one of the transmission lines 3 and 4, and the upper device is instructed. And sends an alarm to notify the abnormality of the transmission lines 3 and 4. Subsequently, the control unit 10 of the control device 1 notifies the end of the diagnostic operation by changing the DIAG1 signal to "L level" at time T2 (state 1). As a result, the VT2 signal rises to the original voltage and the HOK2 signal becomes "L level".

In response to this, the control unit 20 controls the DIAG2
The signal is set to "L level" (state 3), and V
The T1 signal rises to the original voltage and the LOK1 signal becomes "L level". The control unit 10 terminates the diagnostic operation of its own device,
That is, the time t2 from the time T2 when the DIAG1 signal is changed to "L level" until the LOK1 signal becomes "L level" is detected, and if this time t2 is within a predetermined time, it is output from the device itself. It is judged that the stopped diagnostic signal is normally received by the control device 2 and returned, and it is confirmed that the transmission lines 3 and 4 are normal.

If the "L level" LOK1 signal is not detected within a predetermined time after the stop of the diagnostic signal, it is determined that there is an abnormality in one of the transmission lines 3 and 4, and the upper device is instructed. And sends an alarm to notify the abnormality of the transmission lines 3 and 4. In the above description, the case where the control device 1 is in the normal state (state 1) and the control device 2 is in the abnormal state (state 3) has been described as an example, but the present invention is not limited to this, and the control Whether the devices 1 and 2 are normal / normal, abnormal / normal, and abnormal / abnormal, the states of the transmission lines 3 and 4 can be diagnosed in the same manner as described above.

As described above, the signal transmitting unit that outputs a signal indicating the operating state of the control device, that is, normal / abnormal, and indicating the start / end of the diagnosis, and the operating state of the counterpart control device from the received signal are detected and diagnosed When a transmission line is diagnosed by providing a signal receiving unit that detects the start and end of the operation, a signal indicating the operating state and diagnostic operation of the device itself is output to the transmission line and returned from the control device on the other side in response. Since the transmission line is diagnosed by receiving the received signal and confirming the diagnostic operation of the other party's device, it is compared with the conventional case where the status signal has only a binary level. Therefore, the state of the transmission path can be accurately diagnosed regardless of the operating state of the own device and the partner device, and higher reliability can be obtained.

Further, as a signal transmission unit, a status signal output circuit for outputting a status signal indicating the operating state of the control device, and a normal time for outputting a diagnostic signal indicating the start / end of the diagnostic operation when the control device is in a normal state. A diagnostic signal output circuit and an abnormal diagnostic signal output circuit that outputs a diagnostic signal when the control device is in an abnormal state are provided, and as a signal receiving unit, a status signal receiving circuit that detects the operating state of the control device and a normal state Since the normal-time diagnostic signal receiving circuit that receives the diagnostic signal of and the abnormal-time diagnostic signal receiving circuit that receives the diagnostic signal of the abnormal state are provided, the diagnostic signal can be reliably output regardless of the state of the device itself. Can be exchanged.

[0029]

As described above, the present invention is a signal for outputting a signal indicating the operating state of the device itself, that is, normal / abnormal and indicating the start / end of diagnosis to the partner device via the first transmission line. The transmitting unit and the signal receiving unit that detects the operation state of the partner device from the signal received from the partner device via the second transmission path and detects the start and end of the diagnostic operation are provided to operate the own device. The signal indicating the state and the diagnostic operation is output from the signal transmitting unit to the first transmission line, and the signal returned from the partner device via the second transmission line in response to this is received by the signal receiving unit and the partner is received. Since the first and second transmission paths are diagnosed by checking the diagnostic operation of the side device, it is possible to perform self-diagnosis as compared with the conventional case where the status signal has only a binary level. Device and partner device Yes Even in the operating state of the record can accurately diagnose the condition of the transmission path, a higher reliability can be obtained.

Further, as a signal transmission unit, a status signal output circuit for outputting a status signal indicating the operating state of the own device, and a normal condition diagnosis for outputting a diagnostic signal indicating the start / end of the diagnostic operation when the own device is in a normal state. A status signal receiving circuit that provides a signal output circuit and a diagnostic signal output circuit at abnormal time that outputs a diagnostic signal when the own device is in an abnormal state, and detects a status signal indicating the operating state of the partner device as a signal receiving unit And a normal-time diagnostic signal receiving circuit that receives a normal-time diagnostic signal and an abnormal-time diagnostic signal receiving circuit that receives a normal-time diagnostic signal are provided. It is also possible to reliably exchange the status signal and the diagnostic signal.

[Brief description of drawings]

FIG. 1 is a block diagram of a redundant redundancy system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of each signal and a transistor when a control device diagnoses a transmission path.

FIG. 3 is a timing chart showing signals of respective parts of FIG.

[Explanation of symbols]

1, 2 ... Control device, 10, 20 ... Control unit, 11, 21 ...
Status signal output circuit, 12, 22 ... Normal-time diagnostic signal output circuit, 13, 23 ... Abnormal-state diagnostic output circuit, 14, 2
4 ... Status signal receiving circuit, 15, 25 ... Normal-time diagnostic signal receiving circuit, 16, 26 ... Abnormal-time diagnostic signal receiving circuit.

Claims (3)

[Claims] 1. In a dual redundant system in which two control devices on the operating side and the standby side are operated in parallel, and the operating states of the other side are monitored, each control device has its own operating state, namely normal / normal. A signal transmitting unit that outputs a signal indicating an abnormality and indicating the start and end of diagnosis to the partner device via the first transmission path, and a partner device from the signal received from the partner device via the second transmission path And a signal receiving unit that detects the start and end of the diagnostic operation, and, when diagnosing the first and second transmission paths, a signal transmitting unit that outputs a signal indicating the operating state and the diagnostic operation of the own device. From the other device to the second transmission line.
And a control unit for diagnosing the first and second transmission lines by receiving a signal returned through the signal transmission unit by the signal receiving unit and confirming the diagnostic operation of the partner device. Redundant redundant system. 2. The duplex redundancy system according to claim 1, wherein the signal transmission unit outputs a status signal output circuit for outputting a status signal indicating an operation state of the own device, and a diagnostic operation when the own device is in a normal state. It has a normal-time diagnostic signal output circuit that outputs a diagnostic signal indicating the start and end of the, and an abnormal-time diagnostic signal output circuit that outputs a diagnostic signal when the device itself is in an abnormal state. A status signal receiving circuit that detects a status signal indicating the operating state of the device, a normal-time diagnostic signal receiving circuit that receives a normal diagnostic signal, and an abnormal diagnostic signal receiving circuit that receives an abnormal diagnostic signal. A redundant redundancy system characterized by. 3. A duplex system in which two control devices on the operating side and the standby side are operated in parallel, and the operating state of the other side is monitored by transmitting and receiving signals to and from each other via the first and second transmission paths. In the redundant system, a signal indicating the operating state and diagnostic operation of the own device is output to the partner device via the first transmission line, and in response thereto, is returned from the partner device via the second transmission line. A method for diagnosing a duplex redundant system, wherein the first and second transmission paths are diagnosed by receiving a signal and confirming a diagnostic operation of a partner device.