JP2014071773A - Duplex control device and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To duplex data transmission in an input/output buffer in a duplex control device.SOLUTION: The duplex control device 1 includes: two programmable controllers 3a and 3b each of which is connected to both of two control transmission channels 2a and 2b in a data transmittable/receivable state; two input/output buffers 4a and 4b each of which is connected to both of the two control transmission channels 2a and 2b in the data transmittable/receivable state; and input/output devices 5 each of which is connected to the two input/output buffers 4a and 4b in the data transmittable/receivable state. Each input/output device 5 receives, from both of the two input/output buffers 4a and 4b, data transmitted from one of the two programmable controllers 3a and 3b, and updates the data.

Description

  The present invention relates to a duplex control device that operates by configuring a programmable controller as a duplex and a control method thereof.

  A control device using a programmable controller is provided to control and monitor field equipment in a power plant such as a nuclear power plant or a chemical plant. In addition, there is a configuration in which a programmable controller is duplexed with one as a regular system and the other as a standby system in order to improve reliability and operating rate.

  Furthermore, a technology has been developed in which a transmission control unit is connected to each of the duplicated control operation units, and switching between normal use and standby is performed between the two transmission control units by a control right switching circuit (for example, see Patent Document 1). .

  Further, a technology has been developed in which a transmission control module is connected to each duplicated control MPU, and each transmission control module is duplicated to transmit data to the IO module (see, for example, Patent Document 2).

JP-A-6-103100 JP 2000-207373 A

  However, in the control device configured as a duplex described in Patent Document 1 described above, since one control right switching circuit performs duplex control of the transmission control unit, this control right switching circuit becomes a duplex common unit and reliability is reduced. There is a risk.

  Further, in the duplex control apparatus described in Patent Document 2 described above, when the duplex control apparatus is operated with one of the control MPUs as a regular system and the other as a standby system, the transmission control module that performs data transmission of each system is the system of each system. It is a single configuration. As a result, when an abnormality occurs in the transmission control module, the operation consisting of the normal system and the standby system cannot be performed, and the reliability may be reduced.

  Accordingly, an object of the present invention is to provide a duplex control device capable of duplexing data transmission in an input / output buffer.

  In order to achieve the above object, the duplex control apparatus of the present invention includes two control transmission lines, two programmable controllers connected to both of the two control transmission lines so that data can be transmitted and received, and two control transmission lines. Two input / output buffers connected to both of the transmission paths so as to be able to transmit / receive data, and two input / output buffers and input / output devices connected to be able to transmit / receive data, respectively. Data transmitted from one of the programmable controllers is received from both of the two input / output buffers and updated.

  Furthermore, in order to achieve the above object, the control method of the duplex control apparatus of the present invention includes two programmable controllers connected to both of the two control transmission lines so that data can be transmitted and received, and two control transmission lines. In a duplex control device comprising two input / output buffers connected to each other so as to be able to transmit / receive data, and two input / output buffers and an input / output device connected to be able to transmit / receive data respectively, the input / output device has two programs. Data transmitted from one of the malable controllers is received from both of the two input / output buffers and updated.

  According to the present invention, data transmission in the input / output buffer can be duplexed in the duplexing control device.

The schematic block diagram which shows the duplication control apparatus which concerns on the 1st Embodiment of this invention. The flowchart which shows the abnormality detection method in the input / output buffer of the duplication control apparatus which concerns on the 2nd Embodiment of this invention. The flowchart which shows the transmission packet monitoring method of the other party of the input / output buffer of the duplication control apparatus which concerns on the 3rd Embodiment of this invention. The schematic block diagram which shows the duplication control apparatus which concerns on the 4th Embodiment of this invention.

  Embodiments of the present invention will be described below.

(First embodiment)
(Constitution)
Hereinafter, the duplexing control apparatus according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing a duplex control apparatus according to the first embodiment of the present invention.

  The duplex control device 1 includes control LANs 2a and 2b, programmable controllers (PLC) 3a and 3b, input / output buffers 4a and 4b, and an input / output device 5.

  The control LANs 2a and 2b are control transmission lines for transmitting and receiving data between the programmable controllers 3a and 3b and the input / output buffers 4a and 4b, and can be replaced with an optical cable or the like in addition to the LAN cable.

  The two programmable controllers 3a and 3b are connected to both of the two control LANs 2a and 2b so as to be able to transmit data. Further, the programmable controllers 3a and 3b can be operated with one as a regular system and the other as a standby system. Further, the programmable controllers 3a and 3b can monitor each other's state by a tracking bus connected to each other, and can switch between the normal system and the standby system.

  The two input / output buffers 4a and 4b are connected to be able to receive data from both of the two control LANs 2a and 2b, respectively. Further, the one or more input / output devices 5 are connected so as to be able to receive data from the two input / output buffers 4a and 4b. As a result, the input / output buffers 4a and 4b can be regarded as a part of the duplex transmission line. The input / output buffers 4a and 4b distribute the output signals received from the programmable controllers 3a and 3b to one or more input / output devices 5 and transmit them, and the input signals received from the one or more input / output devices 5 Are transmitted to the programmable controllers 3a and 3b.

  The input / output device 5 can receive and update an output signal transmitted from one of the programmable controllers 3a and 3b from both of the two input / output buffers 4a and 4b. An output signal from the programmable controller 3a, 3b to the input / output device 5 reaches the input / output device 5 through both the input / output buffers 4a, 4b. The input / output device 5 updates the values of both output signals received from the input / output buffers 4a and 4b. That is, the output signal is updated twice in one cycle of any one of the programmable controllers 3a and 3b. The input / output device 5 is connected to a field device or the like (not shown), and performs operation of the field device, reception of process data from the field device, or the like based on output signals received from the programmable controllers 3a and 3b. .

  Input signals from the input / output device 5 to the programmable controllers 3a and 3b reach the programmable controllers 3a and 3b through both the input / output buffers 4a and 4b. The input / output buffers 4a and 4b can add their own quality information to the input signal. Each programmable controller 3a, 3b can adopt a signal having normal quality information among input signals from the input / output buffers 4a, 4b. Alternatively, when both are normal, one can be adopted according to a criterion such as first-come-first-served basis.

(Function)
The operation of the first embodiment of the present invention will be described below. The input / output device 5 is controlled by the input / output buffers 4a and 4b, and outputs an instruction from the input / output buffers 4a and 4b to a connected field device or the like in the case of an output signal. Output signals output from the programmable controllers 3a and 3b can be updated only when they are normal, with quality information such as a checksum attached to each packet.

  The programmable controllers 3a and 3b are duplicated, and an output command is transmitted to the input / output buffers 4a and 4b from either the normal system or the standby system. The output signal is updated with the signals from the respective input / output buffers 4a and 4b.

  In the case of data input from the input / output device 5 to the programmable controller 3a, 3b, data quality information is added to the input signal and transmitted to the input / output buffers 4a, 4b. Furthermore, the input / output buffers 4a and 4b can add the status of the input / output device 5, the quality information of the data, and the quality information of the input / output buffers 4a and 4b to be transmitted to the programmable controllers 3a and 3b.

  The programmable controllers 3a and 3b can employ the input signals received from the input / output buffers 4a and 4b whose quality information indicates normal. Alternatively, when both are normal, one of them can be adopted according to a criterion such as first-come-first-serve. The programmable controllers 3a and 3b can receive input signals from both the input / output buffers 4a and 4b described above without distinguishing between regular use and standby.

(effect)
According to the first embodiment of the present invention, data transmission in the input / output buffers 4a and 4b can be duplicated. Further, even when one of the input / output buffers 4a and 4b fails, the normal input / output buffers 4a and 4b receive data from both the programmable controllers 3a and 3b, so that a duplex configuration consisting of a normal system and a standby system is provided. Can continue.

  In addition, since the input / output buffers 4a and 4b can be directly connected to the control LANs 2a and 2b, it is not necessary to have a dedicated wiring and connector for connecting the programmable controllers 3a and 3b and the input / output buffers 4a and 4b. Becomes simple.

(Second Embodiment)
(Constitution)
Hereinafter, a duplex control apparatus according to a second embodiment of the present invention will be described with reference to FIG. The same parts as those in the redundant control apparatus according to the first embodiment are denoted by the same reference numerals, and the description of the same configuration is omitted.

  FIG. 2 is a flowchart showing an abnormality detection method in the input / output buffer of the duplex control apparatus according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that the programmable controllers 3a and 3b have a function of monitoring transmission from the input / output buffers 4a and 4b.

(Function)
The operation of the second embodiment of the present invention will be described below.

  When the data transmission from the input / output buffers 4a and 4b is interrupted, the input / output device 5 cannot detect the disconnection of the input / output buffers 4a and 4b, so the input / output device 5 receives data from the programmable controllers 3a and 3b. There is a risk of continuing the update operation.

  Therefore, in the mutual data transmission / reception between the programmable controllers 3a and 3b and the input / output device 5, the programmable controllers 3a and 3b monitor the data transmission from the input / output buffers 4a and 4b (S101). When data transmission from the input / output buffers 4a and 4b is interrupted due to disconnection or failure, data transmission from the programmable controller 3a or 3b to the corresponding input / output buffer 4a or 4b is stopped (S102). At this time, the corresponding input / output buffers 4a and 4b detect their own failure due to a transmission timeout.

(effect)
According to the second embodiment of the present invention, a failure can be detected also on the input / output buffers 4a, 4b side. In particular, since the input / output device 5 and the input / output buffers 4a and 4b are provided near the field equipment in the plant, it is possible to detect a transmission abnormality on the field side. Furthermore, since the data update in the input / output device 5 can be stopped, a fail-safe operation can be performed.

(Third embodiment)
(Constitution)
Hereinafter, a duplexing control apparatus according to a third embodiment of the present invention will be described with reference to FIG. The same parts as those in the redundant control apparatus according to the first embodiment are denoted by the same reference numerals, and the description of the same configuration is omitted.

  FIG. 3 is a flowchart showing a transmission packet monitoring method of the counterpart system of the input / output buffer of the duplex control apparatus according to the third embodiment of the present invention. The second embodiment is different from the first embodiment in that the input / output buffers 4a and 4b have their own failure determination function, and the failure mode has two or more stages including a minor failure and a major failure. is there. Here, the minor failure is a minor failure that can be normally restored by reset restart. A serious failure is a serious failure with a high possibility that it cannot return normally by reset restart. Further, one input / output buffer 4a, 4b monitors the state of the paired counterpart input / output buffer 4a, 4b with a transmission packet.

(Function)
The operation of the third embodiment of the present invention will be described below.

  The input / output buffers 4a and 4b can perform the failure retry process by reset restart or the operation continuation up to the most severe failure state when detecting the own failure. Here, when failure retry processing is performed by reset restart, there is a possibility that the entire system is temporarily affected by reset restart of both the input / output buffers 4a and 4b. Further, when the operation up to the most serious failure state is continued, when a failure occurs in the counterpart input / output buffer 4a, 4b, there is a possibility that both systems fail to operate and the soundness of the entire system cannot be maintained.

  First, the input / output buffers 4a and 4b confirm the state of the own system (S201). Further, the status of the partner system is monitored with the transmission packet (S202). For monitoring transmission packets, the input / output buffers 4a and 4b may be connected by a dedicated line so that transmission packets can be transmitted and received with each other, or transmission packets may be transmitted and received bypassing the control transmission lines 2a and 2b.

  When the counterpart system is in a normal state, the input / output buffers 4a and 4b perform a failure retry process for reset restart when the own system has a minor fault (S202). If the local system is normal, continue operation. If the partner system is in a failure state, the own system continues to operate until the most severe failure state (S203).

(effect)
According to the third embodiment of the present invention, the input / output buffers 4a and 4b have two or more stages of failure modes, and by selecting reset restart and operation continuation according to the state of the partner system, It is possible to prevent the entire duplex control device 1 from becoming inoperable.

(Fourth embodiment)
(Constitution)
Hereinafter, a duplexing control apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. The same parts as those in the redundant control apparatus according to the first embodiment are denoted by the same reference numerals, and the description of the same configuration is omitted.

  FIG. 4 is a schematic configuration diagram of a duplex control apparatus according to the fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in that the input / output buffer 4a shown in FIG. 1 is divided into a control LAN connection unit 6a and input / output board connection units 7a and 7c, and the input / output shown in FIG. The buffer 4b is divided into a control LAN connection unit 6b and input / output board connection units 7b and 7d. One or more input / output devices 5 are connected to the input / output board connection portions 7a and 7b and the input / output board connection portions 7c and 7d.

(Function)
The operation of the fourth embodiment of the present invention will be described below.

  In the first embodiment, the input / output buffer 4a is directly connected to the input / output device 5, and the number of connectable input / output devices 5 is limited. Therefore, a plurality of input / output board connection sections 7a and 7c are connected to the control LAN connection section 6a, and a plurality of input / output devices 5 are connected to the respective input / output board connection sections 7a and 7c. As a result, the number of connections on the input / output device 5 side and the number of transmission packets to the control LAN connection unit 6a can be suppressed, and a large-scale system can be constructed with a simple configuration in the control LANs 2a and 2b.

(effect)
According to the fourth embodiment of the present invention, the number of connections of the input / output devices 5 to the control LANs 2a and 2b can be increased with a simple configuration.

  The first to fourth embodiments described above can be combined as appropriate.

1 ... Redundant control device 2a, 2b ... Control LAN
3a, 3b ... Programmable controller (PLC)
4a, 4b ... I / O buffer 5 ... I / O devices 6a, 6b ... Control LAN connections 7a, 7b, 7c, 7d ... I / O board connections

Claims (5)

Two control transmission lines,
Two programmable controllers connected to both of these two control transmission lines so that data can be transmitted and received,
Two input / output buffers respectively connected to both of the two control transmission lines so as to be able to transmit and receive data;
These two input / output buffers and input / output devices connected to each other so as to be able to transmit and receive data are provided
The input / output device receives and updates data transmitted from either of the two programmable controllers from both of the two input / output buffers.   The programmable controller checks the data transmission received from the input / output buffer, and when the transmission is interrupted, stops the transmission from the programmable controller to the corresponding input / output buffer. The duplex control device according to claim 1, wherein an abnormality is detected. The input / output buffer has two or more modes at the time of failure,
The status of the partner input / output buffer is monitored by a transmission packet, and the failure restart process of reset restart and the operation continuation until the most severe failure state are selected according to the state of the partner input / output buffer. The duplex control device according to claim 1 or 2.   4. The input / output buffer is divided into a control transmission line connection section and a plurality of input / output board connection sections, and the plurality of input / output devices are connected to the plurality of input / output board connection sections. The duplex control device according to any one of the above.   Two programmable controllers each connected to both of the two control transmission lines so as to be able to transmit / receive data, two input / output buffers respectively connected to both of the two control transmission lines so as to be able to transmit / receive data, In a duplex control device including two input / output buffers and an input / output device connected so as to be able to transmit and receive data, the input / output device transmits data transmitted from one of the two programmable controllers to the two input / output devices. A control method for a duplex control apparatus, comprising: receiving from both buffers and updating.

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