JP2017220842A - Duplex switching system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duplex switching system capable of system switching even if an opposite system is in a power off state.SOLUTION: A duplex switching system configures a duplex system of a control system and a standby system and the control system and standby system give notice of system switching to each other by optical communication. When power is off in its system, a digital output unit 14a of the system outputs a digital signal indicating off via another line different from optical communication, and when a digital input unit 15b in an opposite system receives the digital signal, it notifies a system switching unit 12b, and the system switching unit 12b in turn switches to the control system if the system is the standby system.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a redundant switching system that performs system switching of a redundant control device using optical communication in a supervisory control system for monitoring and controlling a plant.

In the duplex switching system using the conventional optical communication, duplexing is performed by the A system and the B system, and the status notification is performed between the A system and the B system by optical communication.
A case will be described in which an abnormality occurs in the A system when the A system operates as a control system and the B system operates as a standby system and both the A system and the B system are normal.
At this time, the A-system own-system state monitoring unit detects an abnormal state and transmits it to the A-system switching unit. The system switching unit of the A system performs state transition of the A system from the control state to the standby state.
Then, the state is notified from the A system to the B system switching unit by optical communication, and the B system switching unit confirms that the A system is a standby system and in an abnormal state, and waits for the B system. Transitions from the system to the control system.

Japanese Patent Laid-Open No. 4-291523 (pages 2 and 3, FIG. 1)

As described above, since the system switching is realized by notifying the state between the A system and the B system through the optical communication, the system switching cannot be realized when the optical communication cannot be normally performed.
In particular, when the partner system is powered off from the control state, or when the power is shut off from the beginning, the system that is operating normally should be the control system, but the partner system power is off. Therefore, there is a problem that correct system switching operation cannot be performed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a duplex switching system that can perform system switching even when the power of the counterpart system is cut off.

  The duplex switching system according to the present invention is a duplex switching system that configures a dual system of a control system and a standby system and notifies system switching to each other, and a line for notifying system switching when the power of the own system is shut down Is a signal output unit that outputs an OFF signal to another line, a signal input unit that receives an OFF signal output by the signal output unit of the partner system, and the own system from either the control system or the standby system A system switching unit for switching to the other is provided, and the system switching unit switches to the control system when the own system is a standby system when an OFF signal is input to the signal input unit.

  According to the present invention, a duplex switching system that forms a dual system of a control system and a standby system and notifies system switching to each other, and is a line different from a line that notifies system switching when the power of the own system is cut off A signal output unit that outputs an OFF signal to the signal, a signal input unit that receives an OFF signal output by the signal output unit of the counterpart system, and a system that switches the own system from one of the control system and the standby system to the other When the OFF signal is input to the signal input unit, the system switching unit switches to the control system when the own system is a standby system. It can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the duplex switching system by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the duplex switching system by Embodiment 1 of this invention. It is a block diagram which shows the duplication switching system by Embodiment 2 of this invention. It is a block diagram which shows the duplication switching system by Embodiment 3 of this invention. It is a block diagram which shows the duplication switching system by Embodiment 4 of this invention.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a duplex switching system according to Embodiment 1 of the present invention.
In FIG. 1, a control device 10 is duplicated into an A system and a B system, and performs monitoring and control of a plant by using one as a control system and the other as a standby system. Each of the A-system and B-system control devices 10 is configured as follows.
The own system state monitoring unit 11 detects an abnormal state of the own system. The system switching unit 12 switches the state of the own system from the control system to the standby system or from the standby system to the control system. The optical transmission / reception unit 13 performs optical communication between the A system and the B system, and notifies the partner system when the own system performs system switching.
The digital output of the digital output unit 14 (signal output unit) is turned off when the own system is powered off. The digital signal of the counterpart digital output unit 14 is input to the digital input unit 15 (signal input unit) through a line different from the optical communication.
Each code is assigned with a for the A system and b for the B system.

Next, the operation will be described.
First, a case where optical communication is normal will be described.
When an abnormality occurs in the A system while the A system is operating normally as the control system and the B system as the standby system, the own system state monitoring unit 11a of the A system detects the abnormal state, and the A system To the system switching unit 12a. The A system switching unit 12a performs a state transition of the A system from the control state to the standby state. That is, the A system is switched from the control system to the standby system.
Then, the system switching unit 12b notifies the system switching unit 12b of the system B by optical communication from the system A optical transmission / reception unit 13a. After confirming that the state is in the state, the state of the B system is changed from the standby state to the control state.

Next, the operation when the A system is powered off from the state where both systems are operating normally with the A system as the control system and the B system as the standby system will be described with reference to FIG.
If the A system is the control system, the B system is the standby system, and both systems are operating normally (step S1), and the A system is powered off, the digital signal of the A system digital output unit 14a is turned off. (Step S2).
The B-system digital input unit 15b confirms that the digital signal of the A-system digital output unit 14a is OFF, and detects the power-off of the A system (step S3). The B system switching unit 12b receives the power-off state from the digital input unit 15b, and transitions the own system from the standby system to the control system.

  According to the first embodiment, according to the above, even when the partner system is powered off, it is possible to know the power shutdown, perform system switching, and improve the reliability of duplex switching using optical communication. Is possible.

Embodiment 2. FIG.
FIG. 3 is a block diagram showing a duplex switching system according to Embodiment 2 of the present invention.
3, reference numerals 10 to 15 are the same as those in FIG. In FIG. 3, as a configuration for diagnosing the digital output unit 14 in each control device 10, a diagnostic unit 16 that diagnoses the digital output unit 14, and a diagnosis start command or notification of normal diagnosis from the diagnostic unit 16 And a diagnostic signal output unit 17 for outputting a corresponding digital signal, and a diagnostic signal input unit 18 for inputting the output of the diagnostic signal output unit 17 through a line different from the optical communication.
In FIG. 3 as well, each reference numeral is assigned with a for the A system and b for the B system.

Next, the operation will be described.
In the second embodiment, failure diagnosis of the digital output unit 14 is performed with the configuration of FIG. 3, thereby further improving the reliability.
The diagnosis unit 16 issues a diagnosis start command to the diagnosis signal output unit 17 of the own system at a certain cycle.
For example, the A-system diagnosis signal output unit 17a receives a command and turns on a start digital signal (diagnosis start signal). The counterpart diagnostic signal input unit 18b receives the start digital signal ON and notifies the diagnosis unit 16b of the start of diagnosis.
The B-system diagnosis unit 16b determines the start of diagnosis and instructs the digital output unit 14b to turn off in a simulated manner. The digital output unit 14b receives this command and turns off the digital signal in a simulated manner.

On the other hand, the A-system digital input unit 15a receives the OFF signal from the digital output unit 14b and notifies the diagnosis unit 16a of the OFF state.
The diagnosis unit 16a confirms that the digital signal of the counterpart system is OFF, and notifies the diagnosis signal output unit 17a that the diagnosis is normal. The diagnostic signal output unit 17a receives notification of normal diagnosis and turns on a normal digital signal.
The B-system diagnostic signal input unit 18b, which is the counterpart system, receives the normal digital signal ON from the diagnostic signal output unit 17a and notifies the diagnostic unit 16b of normality.
The diagnosis unit 16b receives the normal notification and instructs the digital output unit 14b to release the simulated OFF. The digital output unit 14b receives the simulation operation cancel command and returns to ON.

Finally, the A-system digital input unit 15a confirms that the digital signal of the digital output unit 14b has returned to ON, and notifies the diagnosis unit 16a. The diagnosis unit 16a confirms that the counterpart digital signal has returned to ON, and notifies the diagnosis signal output unit 17a of completion of diagnosis.
Upon completion of the diagnosis, the diagnosis signal output unit 17a returns the start and normal digital signal to OFF.
Further, the diagnosis unit 16a notifies the system switching unit 12a that the system switching unit 12a is not operating erroneously during the diagnosis, and the system switching unit 12a receives a signal from the digital input unit 15a during the diagnosis. Operates not to monitor status.

  According to the second embodiment, it is possible to further improve the reliability of duplex switching using optical communication by performing failure diagnosis of the digital output unit.

Embodiment 3 FIG.
FIG. 4 is a block diagram showing a duplex switching system according to Embodiment 3 of the present invention.
In FIG. 4, reference numerals 10 to 16 are the same as those in FIG. In FIG. 4, the diagnostic signal output unit 17 and the diagnostic signal input unit 18 in FIG. 3 are not provided.

In the third embodiment, failure diagnosis of the digital output unit 14 is performed with the configuration of FIG. 4, thereby further improving the reliability.
In the third embodiment, as shown in FIG. 4, the diagnostic signal input unit 18 and the diagnostic signal output unit 17 of the second embodiment are not provided, and the transmission / reception of the diagnostic signal is performed using the optical transmission / reception unit 13. did.
The operation of the third embodiment is also performed via the optical transmission / reception unit 13 instead of transmitting the diagnostic digital signal from the diagnostic signal output unit 17 to the diagnostic signal input unit 18. Other than this, the operation is the same as in the second embodiment.

  According to the third embodiment, as in the second embodiment, the reliability of duplex switching using optical communication can be further improved.

Embodiment 4 FIG.
FIG. 5 is a block diagram showing a duplex switching system according to Embodiment 4 of the present invention.
In FIG. 5, reference numerals 10 to 13 are the same as those in FIG. In FIG. 5, each control device 10 is provided with a power supply output unit 19 that outputs the voltage of the internal power supply of the own system to the counterpart system, and a power supply monitoring unit 20 that monitors the output of the power supply output unit 19 of the counterpart system.

  The fourth embodiment has the configuration shown in FIG. 5, and each system outputs the voltage of its own internal power supply to the partner system by the power supply output unit 19. The power supply monitoring unit 20 monitors the voltage of the power supply of the partner system, and when a power monitoring abnormality occurs, it is determined that the power supply of the partner system has been cut off, and system switching is performed so that the self system becomes the control system.

  According to the fourth embodiment, it is possible to improve the reliability of duplex switching using optical communication by monitoring the power supply of the counterpart system as described above.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

10 control device, 11 own system state monitoring unit, 12 system switching unit, 13 optical transmission / reception unit,
14 digital output unit, 15 digital input unit, 16 diagnostic unit, 17 diagnostic signal output unit, 18 diagnostic signal input unit, 19 power supply output unit, 20 power supply monitoring unit

Claims (4)

A redundant switching system that configures a dual system of a control system and a standby system and notifies system switching to each other,
A signal output unit that outputs an OFF signal to a line different from the line that notifies system switching when the power of the own system is cut off,
A signal input unit to which an OFF signal output by the signal output unit of the counterpart system is input;
And a system switching unit that switches the own system from one of the control system and the standby system to the other,
The duplex switching system characterized in that the system switching unit switches to the control system when the own system is a standby system when the OFF signal is input to the signal input unit.   The duplex switching system according to claim 1, further comprising a diagnosis unit configured to cause the signal output unit of the counterpart system to output a simulated OFF signal so as to diagnose the signal output unit of the counterpart system. A diagnostic signal output unit for outputting a diagnostic signal by the diagnostic unit;
And a diagnostic signal input unit to which the diagnostic signal output from the diagnostic signal output unit of the counterpart system is input,
The diagnostic signal includes a diagnostic start signal,
The diagnostic unit, when the diagnostic start signal from the partner system is input to the diagnostic signal input unit, causes the signal output unit of its own system to output a simulated OFF signal. 2. The duplex switching system according to 2. A redundant switching system that configures a dual system of a control system and a standby system and notifies system switching to each other,
A power output unit that outputs the internal power supply of its own system,
A power monitoring unit that receives the internal power output from the power output unit of the counterpart system and monitors the input internal power of the counterpart system;
And a system switching unit that switches the own system from one of the control system and the standby system to the other,
The duplex switching system, wherein the system switching unit switches to the control system when the own system is a standby system when the power supply monitoring unit detects an abnormality in the internal power supply of the counterpart system.

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