JP2016058013A - Control system, relay devices, and control devices - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a redundant control system in which availability is improved by reducing, compared to a conventional system, an occurence frequency of switching between an active system and a standby system.SOLUTION: A relay device that is connected via a network device connection bus to one of two control devices, one of which serves as an active system and the other of which serves as a standby system, and also connected to an IO network, is connected to the other control device via redundant communication means. The relay device is further connected, via an equalization cable, to the other relay device that is connected to the other control device via the network device connection bus. When a connection destination of the network device connection bus is the active system, at least one of processing for transferring monitoring data received from the IO network to the control device of the active system and processing for transferring the monitoring data to the other relay device is executed. When the connection destination of the network device connection bus is the standby system, processing for transferring the monitoring data received via the equalization cable to the control device of the active system via the redundant communication means is executed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a control system including an active system and a standby system control apparatus and a relay apparatus.

In industrial facilities such as factories and various plants, a communication system called a control system is often constructed to control various operations. The control system includes a control device that collects monitoring data from sensors installed in an industrial facility and performs drive control of an electric motor or the like according to the collection result. Such control devices include DCS (Distributed Control).
System: a distributed control system or a distributed control device) or a programmable logic controller (hereinafter, PLC) is used. In a general FA (Factory Automation) system, PLC is often used as a control device, and in plant facilities that require high reliability, DCS is often used as a control device. This is because DCS is more reliable than PLC. A device to be monitored by a control device such as the above sensor or a device to be controlled such as an electric motor (hereinafter collectively referred to as an “IO slave device”) is a network (or serial bus) called an IO network. And a control network (a network that performs communication based on a dedicated protocol such as FL-net). The control device is connected to the IO network via a network device such as a relay device (for example, a gateway device).

  In this type of control system, in order to avoid an operation stop caused by a failure of a control device or the like, it is common to perform a duplex control device and a dual data transmission path for monitoring data. Redundant control device means that two control devices are provided and one of them is operated as an active system and the other as a standby system. Each of these two control devices collects monitoring data and performs a predetermined calculation for device control using the collected monitoring data (or the collected monitoring data and past calculation results). The active control device performs control based on the calculation result, and the standby control device prepares for the stop of the active control device. The standby control device operates as an active system when the active system stops (or stops), and continues device control. Here, as a specific example of the stop of the active control device, an unexpected stop due to the occurrence of some failure or malfunction, a pre-scheduled stop due to maintenance, or the like can be considered. The standby control device provides for both of these two types of stops. Duplexing of data transmission paths means that, for example, a data transmission path from an IO slave device to one of the duplexed control devices and a data transmission path to the other are provided separately. Hereinafter, a control system in which both the control device and the data transmission path are duplicated is referred to as a “redundant control system”.

  FIG. 19 is a diagram illustrating a configuration example of a conventional redundancy control system 3. In the redundant control system 3 shown in FIG. 19, an IO slave device such as various sensors connected to an IO network and installed in an industrial facility, a control target device such as an electric motor connected to the control network, an operating state of the control device, etc. Illustration of a monitoring system for monitoring the above is omitted. The redundant control system 3 in FIG. 19 has two control devices, a control device 10A and a control device 10B, and two network devices, a network device 20A and a network device 20B. One of the control device 10A and the control device 10B becomes an active system, and the other becomes a standby system to prepare for the stop of the active system. Further, the control device 10A is connected to the network device 20A via the network device connection bus 60A, and the control device 10B is connected to the network device 20B via the network device connection bus 60B. The network device 20A and the network device 20B are connected to the network 30 '. The network 30 'is an IO network.

  In the redundant control system 3 shown in FIG. 19, each of the control device 10A and the control device 10B is connected by an equalization cable 40 so that the other state can be monitored. As described above, the standby control device prepares for an unexpected stop caused by a failure or a planned stop such as a maintenance for the active control device. The control device will be described as an example. Each of the control device 10A and the control device 10B transmits state data indicating the state of the device (the presence or absence of a failure) to the other via the equalization cable 40. For example, when the control device 10A is an active system, the control device 10B that is a standby system refers to the status data transmitted from the control device 10A via the equalization cable 40 and has a failure in the control device 10A. Monitor outbreaks. When the control device 10B detects a failure of the control device 10A from the state data received via the equalization cable 40, the control device 10B starts operation as an active system thereafter. On the other hand, the control device 10A detects that the control device 10B has started operation as an active system by communication via the equalization cable 40, and thereafter operates as a standby system.

  In the redundant control system, even if a failure occurs in the active control device, the active / standby system is switched to collect data from the IO slave device, the operation according to the collection result, and the operation result The control according to can be continued. However, simply switching the active / standby system may cause problems such as sudden changes in the calculation result before and after the switching. This is because the monitoring data sent from the IO slave device to each of the control device 10A and the control device 10B and the computation data representing the computation result sent from each of the control device 10A and the control device 10B to the control target device are completely the same. This is due to the fact that it does not always exist.

  In order to avoid the occurrence of such a problem, in the redundant control system, the equalization of the monitoring data transmitted from each of the IO slave devices to each control device, the equalization of the calculation result by the monitoring data, etc. In general, the processing is executed by each control device. Equalization of monitoring data means that monitoring data received by the active control device via the network device is transmitted to the standby control device via the equalization cable 40, and the standby control device is used as the monitoring data. Is to overwrite the monitoring data received via the network 30 '. In addition, equalization of calculation results means that calculation data indicating calculation results in the active system is transmitted to the standby control device via the equalization cable 40, and the calculation results in the standby system are overwritten with the calculation data. Say that. As an example of the prior art relating to such a redundant control system and equalization, there are techniques disclosed in Patent Document 1 and Patent Document 2.

JP2013-12094A JP2013-152631A

  In the redundant control system 3 shown in FIG. 19, the A system composed of the control device 10A and the network device 20A operates as an active system, and the B system composed of the control device 10B and the network device 20B operates as a standby system. The case will be described. When the network device connection bus 60A connecting the control device 10A and the network device 20A is disconnected, data cannot be transmitted / received between the control device 10A and the network device 20A, and the control device 10A indicates that a failure has occurred. The state data is transmitted to the control device 10B via the equalization cable 40. When the control device 10B detects a failure of the control device 10A from the received state data, the control device 10B starts the operation as the active system, and the state data indicating that the control device 10B has started the operation as the active system is equalized cable 40. To the control device 10A. The control device 10A receives state data indicating that the control device 10B has started operation as an active system via the equalization cable 40, and thereafter operates as a standby system. As described above, even if the network device connection bus 60A connecting the control device 10A and the network device 20A is disconnected, switching between the active system and the standby system occurs, so that it seems that no particular problem occurs. However, until the switching of the active system / standby system between the control device 10A and the control device 10B is completed, the control of the control target device is performed even though there is no problem with the control device 10A itself that has been the active system so far. The problem that cannot be performed occurs.

  The present invention has been made in view of the above-described problems, and provides a technique that can reduce the frequency of switching between the active system and the standby system and improve the availability of the redundant control system as compared with the prior art. The purpose is to provide.

  In order to solve the above-described problems, the present invention collects monitoring data from devices connected to a network and controls the following first and second control devices and first as control systems that perform control based on the monitoring data. And a control system having a second relay device. One of the first and second control devices is an active system and the other is a standby system. Specific examples of the first and second relay apparatuses include the network apparatus described above. The first relay device is connected to the network and is also connected to the first control device. The first relay device functions as an active relay device if the first control device to which it is connected is an active system, and as a standby relay device if the first control device is a standby system. Function. The second relay device is connected to the network and to the second control device. The second relay device also functions as an active relay device if the second control device to which it is connected is an active system, and as a standby relay device if the second control device is a standby system. Function. The control system includes a redundant communication unit that mediates communication between the first control device and the second relay device and mediates communication between the second control device and the first relay device, and the first relay device. And inter-relay device communication means for mediating communication of the second relay device. Each of the first and second relay devices receives the first processing means for executing the first processing for transferring the monitoring data received via the network to the connected control device, and the first relay device via the network. Second processing means for executing a second process for transferring monitoring data to the other relay apparatus via the inter-relay apparatus communication means; and monitoring data received from the other relay apparatus via the inter-relay apparatus communication means. And third processing means for executing a third process for transferring to the other control device via the redundant communication means. The active relay apparatus executes at least the first process of the first process and the second process, and the standby relay apparatus executes the third process. The active control device performs the above control based on either the monitoring data received from the connection destination relay device or the monitoring data received from the standby relay device via the redundant communication means.

  According to the present invention, the active control device receives monitoring data from at least one of the connection destination relay device and the other relay device via the redundant communication means, and performs control based on the monitoring data. . Therefore, monitoring data can be received even if the connection between the active control device and the active relay device is disconnected, and there is no need to switch the active / standby system for the control device. Therefore, according to the present invention, the frequency of occurrence of switching between the active system and the standby system can be reduced as compared with the conventional redundant control system, and the availability can be improved.

  In a more preferred aspect, each of the first and second relay devices equalizes monitoring data received from the network by communication via the inter-relay device communication means. The second process may be a part of the process for equalizing the monitoring data, or may be a process separate from the process for equalizing the monitoring data. According to this aspect, the equalization of the monitoring data is performed by the first and second relay devices. Therefore, the processing load on the first and second control devices can be reduced as compared with the conventional redundant control system in which the monitoring data is equalized on the control device side.

  In a more preferred aspect, the active relay device executes the second process when the monitoring data cannot be transferred by the first process. When the monitoring data cannot be transferred by the first process, the first process is executed, and as a result, the transfer is impossible, and the monitoring data transfer destination is set prior to the execution of the first process. It is determined whether or not communication is possible, and the case where it is determined that communication is impossible is included. According to this aspect, since the second process is executed only when the monitoring data cannot be transferred to the active control device, whether or not the monitoring data can be transferred to the active control device. Regardless of whether the first and second processes are always executed, waste of the data transmission band in the inter-relay device communication means can be avoided.

  In another preferred aspect, the active relay device executes both the first processing and the second processing, and the active control device monitors the transfer from the connection destination relay device. It is determined whether each of the data and the monitoring data transferred from the standby relay device via the redundant communication means is already received, and if received, the received monitoring data is discarded. If not received, the control is executed based on the received monitoring data. According to this aspect, since it is not determined whether the communication with the control apparatus of the connection destination is possible, the processing load on the relay apparatus can be reduced. Since the active control device determines whether or not the monitoring data has already been received, the operation based on the same monitoring data is not executed repeatedly.

  In a more preferable aspect, the communication device includes an inter-control device communication unit that mediates communication between the first and second control devices, and the active control device generates calculation data based on the received monitoring data, and Each of the first and second control devices equalizes the calculation data by communication via the inter-control device communication means. According to this aspect, the operation data is equalized between the first and second control devices, and the active control device controls the control target device for the operation data that has been equalized. The calculation data calculated by the first and second control devices can be prevented from changing suddenly into different calculation data.

  In order to solve the above-described problems, the present invention collects monitoring data from devices connected to a network and performs control based on the monitoring data as the following first and second control devices and second control devices. A control system having a first relay device and a second relay device is provided. One of the first and second control devices is an active system and the other is a standby system. The first relay device is connected to the network and is also connected to the first control device. The first relay device functions as an active relay device if the first control device to which it is connected is an active system, and as a standby relay device if the first control device is a standby system. Function. The second relay device is connected to the network and to the second control device. The second relay device also functions as an active relay device if the second control device to which it is connected is an active system, and as a standby relay device if the second control device is a standby system. Function. The control system includes a redundant communication unit that mediates communication between the first control device and the second relay device and mediates communication between the second control device and the first relay device, and the first control device. And inter-control device communication means for mediating communication of the second control device. Each of the first and second relay devices receives a first processing means for executing a first process for transferring the monitoring data received via the network to a connection destination control device and the network via the network. And second processing means for executing second processing for transferring the monitored data to the other control device via the redundant communication means. The active relay device executes at least the first process. The standby control device transfers the monitoring data received from the active relay device via the redundancy control communication means to the active control device via the inter-control device communication means. The active control device performs the control based on any one of the monitoring data received from the connection destination relay device and the monitoring data received from the standby control device via the inter-control device communication means. According to this aspect, the active control device receives monitoring data from at least one of the connection destination relay device and the standby control device via the inter-control device communication means, and sends the monitoring data to the monitoring data. A control system for performing control based on the above is provided. Also according to this aspect, the frequency of switching between the active system / standby system of the control device and the relay device can be reduced.

  In a more preferred aspect, the active control device generates calculation data based on the received monitoring data, and each of the first and second control devices is configured to communicate with the communication device between the control devices. Performs equalization of operation data. According to this aspect, the operation data is equalized between the first and second control devices, and the active control device controls the control target device for the operation data that has been equalized. The calculation data calculated by the first and second control devices can be prevented from changing suddenly into different calculation data.

  In a more preferred aspect, the active relay device executes the second process when the monitoring data cannot be transferred by the first process. According to this aspect, since the second process is executed only when the monitoring data cannot be transferred to the active control device, it is possible to transfer the monitoring data to the active control device. Compared with a mode in which both the first and second processes are always executed, it is possible to avoid waste of the data transmission band in the inter-controller communication means.

  In another preferred embodiment, the active relay device executes both the first processing and the second processing, and the active control device receives the monitoring data transferred from the connection-destination relay device. In addition, it is determined whether or not each of the monitoring data transferred from the standby control device via the communication device between the control devices is already received, and if received, the received monitoring data is discarded, If not received, the control is executed based on the received monitoring data. According to this aspect, since it is not determined whether the communication with the control apparatus of the connection destination is possible, the processing load on the relay apparatus can be reduced. Since the active control device determines whether or not the monitoring data has already been received, the operation based on the same monitoring data is not executed repeatedly.

  In a more preferred aspect, the communication device has inter-relay device communication means for mediating communication between the first and second relay devices, and each of the first and second relay devices communicates via the inter-relay device communication means. To equalize the monitoring data received from the network. According to this aspect, since the equalization of the monitoring data is performed between the first and second relay devices, the monitoring data collected by the first and second relay devices changes suddenly and differs from the monitoring data. Can be prevented.

  In addition, the present invention for solving the above-described problems is that one of the first and second control devices, in which one is an active system and the other is a standby system, is connected via a communication device between control device relay devices. As a relay device that is connected and connected to a network to which a device that transmits monitoring data is connected, a relay device having the following first, second, and third processing means is provided. The relay device is connected to the other of the first and second control devices via the redundant communication means, and via another relay device connected to the other control device and the communication device between the relay devices. Connected. The first processing means is means for transferring the monitoring data received via the network to the connection destination of the communication device between control device relay devices. The second processing means is means for transferring the monitoring data received via the network to the connection destination of the inter-relay device communication means. The third processing means is means for transferring the monitoring data received via the inter-relay device communication means to the other control device via the redundant communication means. When the connection destination of the communication device between the control device relay devices is an active system, the relay device uses at least the first processing means among the first processing means and the second processing means. If it is a standby system, transfer is performed by the third processing means. Also according to this aspect, the frequency of switching between the active system / standby system of the control device and the relay device can be reduced.

  In order to solve the above problems, the present invention is connected to one of the first and second control devices, one of which is an active system and the other is a standby system, via a communication device between control device relay devices. In addition, a relay apparatus having the following first and second processing means is provided as a relay apparatus connected to a network to which a device that transmits monitoring data is connected. This relay device is connected to the other of the first and second control devices via redundant communication means. The first processing means is means for transferring the monitoring data received via the network to the connection destination of the communication device between control device relay devices. The second processing means is means for transferring the monitoring data received via the network to the other control device via the redundant communication means. When the connection destination of the communication device between the control device relay devices is the active system, the relay device executes at least the transfer by the first processing unit. Also according to this aspect, the frequency of switching between the active system / standby system of the control device and the relay device can be reduced.

  In addition, the present invention for solving the above-described problems provides the following first and second control devices as control devices in a control system including two control devices in which one is an active system and the other is a standby system. A control device having processing means is provided. This control device is connected to one of two relay devices each connected to a network to which a device for transmitting monitoring data is connected via a communication device between control device relay devices, and to the other via a redundant communication device. Connected. The first processing means is means for performing the control based on the monitoring data received from the connection destination of the control device relay device communication means. The second processing means is means for performing the control based on the monitoring data received from the connection destination of the redundant communication means. When this control device is an active system, the control device performs the control by one of the first processing means and the second processing means. Also according to this aspect, the frequency of switching between the active system / standby system of the control device and the relay device can be reduced.

  In order to solve the above-mentioned problems, the present invention provides a control system including two control devices, one of which is an active system for control and the other of which is a standby system and connected to each other via inter-control device communication means. Provides a control device having first, second and third processing means. This control device is connected to one of two relay devices each connected to a network to which a device for transmitting monitoring data is connected via a communication device between control device relay devices, and to the other via a redundant communication device. Connected. The first processing means is means for performing the control based on the monitoring data received from the connection destination of the control device relay device communication means. The second processing means is means for performing the control based on the monitoring data received from the connection destination of the inter-control device communication means. The third processing means is means for transferring the monitoring data received from the connection destination of the redundant communication means to the connection destination of the inter-control device communication means. The control device performs the control by any one of the first processing means and the second processing means when it is an active system, and when it is a standby system, Transfer by the third processing means is executed. Also according to this aspect, the frequency of switching between the active system / standby system of the control device and the relay device can be reduced.

  As described above, according to the present invention, the frequency of occurrence of switching between the active system and the standby system in the redundant control system can be reduced as compared with the prior art, and the availability of the redundant control system can be improved.

It is a figure which shows the structural example of the redundancy control system (redundancy control system 1 of 1st Embodiment of this invention) containing the network apparatus 200 of an example of the relay apparatus of this invention. It is a block diagram which shows the structural example of the network apparatus 200 of the redundancy control system. It is a block diagram which shows the structural example of the control apparatus 100 of the redundancy control system. It is a figure which shows the flow of transmission of the monitoring data of the redundancy control system 1 when the network apparatus connection bus 60A is normal. FIG. 10 is a diagram for explaining an operation executed by the control unit 210 of the network device 200 according to a relay control program 2642. 12 is a flowchart showing a flow of equalization / transfer processing 2642b executed by the control unit 210 of the network device 200 according to the relay control program 2642. It is a flowchart which shows the flow of the network device reception process which the network device 200 performs. It is a flowchart which shows the flow of the network apparatus transmission process which the network apparatus 200 performs. FIG. 10 is a diagram for explaining an operation executed by the control unit 110 of the control device 100 according to a control program 1542. 7 is a flowchart showing a flow of an equalization process 1542b executed by the control unit 110 of the control device 100 according to a control program 1542. It is a figure which shows the flow of transmission of the monitoring data of the redundancy control system 1 when the network apparatus connection bus 60A is not normal. It is a flowchart which shows the flow of the network device transmission process which the network device 200 of the redundancy control system 1 of 2nd Embodiment of this invention performs. It is a flowchart which shows the flow of the control apparatus reception process which the control apparatus 100 of the redundancy control system 1 performs. It is a figure which shows the flow of transmission of the monitoring data of the redundancy control system 1 when the network apparatus connection bus 60A is normal. In the redundant control system 1 of the modification (8), it is a figure which shows the flow of transmission of the monitoring data when the network apparatus connection bus 60A is not normal. It is a figure which shows the structural example of the redundancy control system 2 of a modification (10). It is a figure which shows the flow of transmission of the monitoring data in the redundancy control system 2 when the network apparatus connection bus 60A is normal. It is a figure which shows the flow of transmission of the monitoring data in the redundancy control system 2 when the network apparatus connection bus 60A is not normal. It is a figure which shows the structural example of the conventional redundancy control system 3. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
(A: Configuration)
FIG. 1 is a diagram illustrating a configuration example of a redundant control system 1 according to the first embodiment of this invention. In FIG. 1, illustration of an IO slave device such as various sensors and control target devices connected to an IO network and a monitoring system for monitoring the operating state of the control device is omitted. The redundant control system 1 is a control system laid in an industrial facility, like the redundant control system 3 shown in FIG. In FIG. 1, the same components as those in FIG. 19 are denoted by the same reference numerals. As apparent from a comparison between FIG. 1 and FIG. 19, the redundant control system 1 is different from the conventional redundant control system 3 shown in FIG. 19 in the following five points. First, it has a control device 100A and a control device 100B instead of the control device 10A and the control device 10B. Second, the network device 200A and the network device 200B are provided instead of the network device 20A and the network device 20B. Third, the network device 200A and the network device 200B are connected by an equalization cable 500. Fourth, the control device 100A and the network device 200B are connected by a redundant connection bus 600. Fifth, the control device 100B and the network device 200A are connected by the redundant connection bus 700.

  Each of the network device 200A and the network device 200B is an embodiment of the relay device of the present invention, and the equalization cable 500 serves as a communication device between relay devices that mediates communication between the relay devices. The network device 200A and the network device 200B are gateway devices like the network device 20A and the network device 20B in FIG. In the redundant control system 1 shown in FIG. 1, monitoring data transmitted from an IO slave device (not shown) is transmitted to the control device 100A via the IO network 30 and the network device 200A, and the IO network 30 and the network device 200B. Is transmitted to the control device 100B. Each of control device 100A and control device 100B, like control device 10A and control device 10B in FIG. 19, collects monitoring data from IO slave devices, and uses computation results (calculations for device control). ), And the calculation result is stored. The control device 100A and the control device 100B may be PLCs or DCSs.

  In the redundant control system 1 shown in FIG. 1, one of the control device 100A and the control device 100B becomes an active system, and controls other devices based on the above calculation results, and the other operates as a standby system. Prepare for system shutdowns (such as the two types of shutdowns described above). When the active system stops, the control device that has been in the standby system thereafter operates as the active system. Note that switching between the active system and the standby system may be realized by a method similar to that of the conventional redundant control system 3.

  As described above, when switching between the active system and the standby system, it is necessary to equalize the monitoring data and equalize the calculation result in order to avoid a sudden change in the calculation result. In the conventional redundant control system 3 shown in FIG. 19, the control device 10A and the control device 10B are made to equalize the monitoring data and the calculation result. However, in this embodiment, the monitoring data is equalized. The network device 200A and the network device 200B perform the digitization, and the control device 100A and the control device 100B perform the equalization of the calculation result. Note that, since the control device 100A and the control device 100B have the same configuration, the network device 200A and the network device 200B are the same when it is not necessary to distinguish between them. In the following description, when it is not necessary to distinguish between the two, the network device 200 is described.

  In the present embodiment, the network device 200 also has a distinction between the active system and the standby system, and performs different operations in the active system and the standby system. More specifically, the network device 200 communicates with its connection destination control device 100 to determine whether or not the connection destination control device 100 is an active system. The network device 200 behaves as an active network device if the connection-destination control device 100 is an active system, and conversely behaves as a standby network device if the connection-destination control device 100 is a standby system. . That is, in this embodiment, of the network device 200A and the network device 200B, the one connected to the active control device 100 is the active system, and the one connected to the standby control device 100 is the standby system. Become. When the control device 100 itself fails and the active / standby system is switched for the control device 100, the active and standby systems are also switched for the network device 200 depending on the switching.

In the conventional redundant control system 3, when the network device connection bus that connects the active network device and the active control device is disconnected, the network device or the control device is switched between the active system and the standby system. It was. However, the present embodiment is configured such that even if the network device connection bus 60A is disconnected, the control of the control target device can be continued without switching the active / standby system of the network device 200 or the control device 100. In this respect, there is a feature of the present embodiment.
Below, it demonstrates centering around the structure of the network device 200 and the control apparatus 100 which show the characteristic of the structure of the redundant control system 1 notably.

  First, the configuration of the network device 200 will be described. FIG. 2 is a block diagram illustrating a configuration example of the network device 200. As shown in FIG. 2, the network device 200 includes a control unit 210, a first communication interface (hereinafter abbreviated as “I / F”) unit 220, a second communication I / F unit 230, and a third communication I / F unit. 240, a fourth communication I / F unit 250, a storage unit 260, and a bus 270 that mediates data exchange between these components.

  The control unit 210 is, for example, a CPU (Central Processing Unit). The control unit 210 functions as a control center of the network device 200 by executing the relay control program 2642 stored in the storage unit 260 (more precisely, the nonvolatile storage unit 264). Details of processing executed by the control unit 210 in accordance with the relay control program 2642 will be clarified later. Each of first communication I / F unit 220, second communication I / F unit 230, third communication I / F unit 240, and fourth communication I / F unit 250 is, for example, a NIC (Network Interface Card). The role of each of these communication I / F units is as follows.

  The first communication I / F unit 220 is connected to the IO network 30. The first communication I / F unit 220 receives monitoring data transmitted from the connection-destination IO network 30 and sends operation data to the connection-destination control network. The first communication I / F unit 220 includes a communication buffer that accumulates monitoring data received from the connection destination IO network 30 and operation data to be transmitted to the connection destination IO network 30 (not shown in FIG. 2).

  The second communication I / F unit 230 is connected to the control device 100 via a network device connection bus. More specifically, the second communication I / F unit 230 of the network device 200A is connected to the control device 100A via the network device connection bus 60A. Similarly, the second communication I / F unit 230 of the network device 200B is connected to the control device 100B via the network device connection bus 60B. The second communication I / F unit 230 receives calculation data transmitted from the connection destination control device 100 and transmits monitoring data to the connection destination control device 100. The second communication I / F unit 230 includes a communication buffer that accumulates calculation data received from the connection destination control device 100 and monitoring data to be transmitted to the connection destination control device 100 (not shown in FIG. 2).

  The third communication I / F unit 240 has a port to which an equalization cable is connected, and the equalization cable 500 is connected to the port. The third communication I / F unit 240 performs communication for equalization of monitoring data with the other network device via the equalization cable 500. The third communication I / F unit 240 includes a communication buffer for accumulating monitoring data for communicating with a connection destination network device (not shown in FIG. 2).

  The fourth communication I / F unit 250 is connected to the control device 100 via the redundant connection bus. More specifically, the fourth communication I / F unit 250 of the network device 200A is connected to the control device 100B via the redundant connection bus 700. Similarly, the fourth communication I / F unit 250 of the network device 200B is connected to the control device 100A via the redundant connection bus 600. The fourth communication I / F unit 250 receives calculation data transmitted from the connection destination control device 100 and sends monitoring data to the connection destination control device 100. The fourth communication I / F unit 250 includes a communication buffer that accumulates calculation data received from the connection destination control device 100 and monitoring data to be transmitted to the connection destination control device 100 (not shown in FIG. 2).

  As illustrated in FIG. 2, the storage unit 260 includes a volatile storage unit 262 and a nonvolatile storage unit 264. The volatile storage unit 262 is, for example, a RAM (Random Access Memory). The volatile storage unit 262 is used as a work area for executing the relay control program 2642. The volatile storage unit 262 also serves as a monitoring data buffer 2622 that temporarily stores monitoring data to be transmitted to the control device 100. Furthermore, the volatile storage unit 262 stores an operation / standby flag indicating whether the network device 200 having the volatile storage unit 262 is operating as an active system or a standby system. . The nonvolatile storage unit 264 is, for example, a flash ROM. The non-volatile storage unit 264 stores a relay control program 2642 in advance.

  The control unit 210 reads the relay control program 2642 from the non-volatile storage unit 264 to the volatile storage unit 262 when the power (not shown) of the network device 200 is turned on or reset, and starts its execution. The control unit 210 operating in accordance with the relay control program 2642 monitors the operation state of the connection destination control apparatus 100 and executes a process of setting an operation / standby flag according to the monitoring result. In addition to the relay process 2642a, The equalization / transfer process 2642b is executed. The details of the relay process 2642a and the equalization / transfer process 2642b will be clarified in the operation example, but the outline is as follows. That is, in the equalization / transfer processing 2642b, the processing for equalizing the monitoring data collected from the IO slave device and the monitoring data are transferred to the other network device 200 by communication via the equalization cable 500. Processing is included. On the other hand, the relay process 2642a is roughly divided into two processes. One process is a process of transferring the monitoring data equalized by the equalization / transfer process 2642b to the control device 100 connected to the second communication I / F unit 230. Another process is a process of transferring the monitoring data transferred from the other network apparatus 200 by the equalization / transfer process 2642b to the control apparatus 100 connected to the fourth communication I / F unit 250.

  Next, the configuration of the control device 100 will be described. FIG. 3 is a block diagram illustrating a configuration example of the control device 100. As shown in FIG. 3, the control device 100 includes a control unit 110, a first communication I / F unit 120, a second communication I / F unit 130, a third communication I / F unit 140, a storage unit 150, and their configurations. A bus 160 that mediates data exchange between elements is included.

  The control unit 110 is a CPU, for example. The control unit 110 functions as a control center of the control device 100 by executing a control program 1542 stored in the storage unit 150 (more precisely, the nonvolatile storage unit 154). Details of processing executed by the control unit 110 according to the control program 1542 will be made clear later. Each of first communication I / F unit 120, second communication I / F unit 130, and third communication I / F unit 140 is, for example, a NIC (Network Interface Card). The role of each of these communication I / F units is as follows.

  The first communication I / F unit 120 is connected to the network device 200 via a network device connection bus. More specifically, the first communication I / F unit 120 of the control device 100A is connected to the network device 200A via the network device connection bus 60A. Similarly, the first communication I / F unit 120 of the control device 100B is connected to the network device 200B via the network device connection bus 60B. The first communication I / F unit 120 receives monitoring data transmitted from the connection destination network device 200 and transmits calculation data to the connection destination network device 200. The first communication I / F unit 120 includes a communication buffer that accumulates monitoring data received from the connection destination network device 200 and operation data to be transmitted to the connection destination network device 200 (not shown in FIG. 3).

  The second communication I / F unit 130 has a port to which an equalization cable is connected, and the equalization cable 400 is connected to the port. The second communication I / F unit 130 performs communication for equalization of calculation data with the other control device via the equalization cable 400. The second communication I / F unit 130 has a communication buffer that accumulates calculation data for communicating with the connection destination control device (not shown in FIG. 3).

  The third communication I / F unit 140 is connected to the network device 200 via the redundant connection bus. More specifically, the third communication I / F unit 140 of the control device 100A is connected to the network device 200B via the redundant connection bus 600. Similarly, the third communication I / F unit 140 of the control device 100B is connected to the network device 200A via the redundant connection bus 700. The third communication I / F unit 140 receives monitoring data transmitted from the connection destination network device 200 and transmits operation data to the connection destination network device 200. The third communication I / F unit 140 includes a communication buffer for accumulating monitoring data received from the connection destination network device 200 and operation data to be transmitted to the connection destination network device 200 (not shown in FIG. 3).

  As illustrated in FIG. 3, the storage unit 150 includes a volatile storage unit 152 and a nonvolatile storage unit 154. The volatile storage unit 152 is, for example, a RAM (Random Access Memory). The volatile storage unit 152 is used as a work area for executing the control program 1542. The volatile storage unit 152 also serves as a calculation data buffer 1522 that temporarily stores calculation data to be transmitted to the network device 200. Further, the volatile storage unit 152 stores an operation / standby flag indicating whether the control device 100 having the volatile storage unit 152 is operating as an active system or a standby system. . The nonvolatile storage unit 154 is, for example, a flash ROM. The nonvolatile storage unit 154 stores a control program 1542 in advance.

The control unit 110 reads the control program 1542 from the nonvolatile storage unit 154 to the volatile storage unit 152 when the power (not shown) of the control device 100 is turned on or reset, and starts executing the control program 1542. The control unit 110 operating according to the control program 1542 monitors the operation state of the other control device 100 connected via the equalization cable 400 and sets the operation / standby flag according to the monitoring result. In addition to executing processing, arithmetic processing 1542a and equalization processing 1542b are executed. Although details of the arithmetic processing 1542a and the equalization processing 1542b will be clarified in the operation example, the outline is as follows. That is, the equalization process 1542b is a process for equalizing the operation data through communication via the equalization cable 400. The calculation processing 1542a calculates the monitoring data received from the connected network device 200A or the network device 200B, generates calculation data based on the calculation result, and connects the calculation data to the first communication I / F unit 120. This is a process of transferring to the network device 200.
The above is the configuration of the entire redundant control system 1, the network device 200, and the control device 100.

(B: Operation)
Next, the operation of this embodiment will be described with reference to FIGS. In the operation example described below, it is assumed that the A system composed of the control device 100A and the network device 200A is an active system, and the B system composed of the control device 100B and the network device 200B is a standby system. Further, in the operation example described below, the monitoring data buffer 2622 of each of the network device 200A and the network device 200B is empty at the time of starting the operation, and further, the calculation data of each of the control device 100A and the control device 100B at the time of starting the operation. A case where the buffer 1522 is empty will be described. Further, hereinafter, the monitoring data transmitted to the network device 200A is referred to as “monitoring data A”, and the monitoring data transmitted to the network device 200B is referred to as “monitoring data B”. Although the monitoring data A and the monitoring data B are basically the same data, they may be slightly different depending on the sampling timing shift when sampling each. In the following, calculation data calculated by the control device 100A and generated based on the calculation result is referred to as “calculation data A”, and calculation data calculated by the control device 100B and generated based on the calculation result is referred to as “calculation data B”. The calculation data A and the calculation data B are basically the same data, but may be slightly different because the control device 100 involved in each calculation is different.

(B-1: Operation when network device connection bus 60A is normal)
First, the operation when the network device connection bus 60A is normal as shown in FIG. 4 will be described. The network device connection bus 60A being normal means that the network device connection bus 60A is not disconnected and the network device 200A can normally communicate with the control device 100A.

  The IO slave device samples an input signal (or an output signal from a sensor or the like), generates monitoring data to be transmitted to each of the control device 100A and the control device 100B, and transmits the monitoring data to the IO network 30. The monitoring data transmitted by the IO slave device includes a header including information (communication address and node number) indicating the transmission destination and transmission source of the monitoring data and an identifier (for example, sequence number) uniquely indicating the monitoring data. Has been granted. The monitoring data transmitted from the IO slave device is transmitted to each of the network device 200A and the network device 200B via the IO network 30.

  When receiving the monitoring data transmitted from the IO network 30, the first communication I / F unit 220 of the network device 200 </ b> A writes the received monitoring data in the communication buffer in the first communication I / F unit 220. Similarly, in the network device 200B, the monitoring data received from the IO network 30 is written in the communication buffer in the first communication I / F unit 220 of the network device 200B. That is, in this operation example, the monitoring data A is stored in the communication buffer in the first communication I / F unit 220 of the network device 200A, and the communication buffer in the first communication I / F unit 220 of the network device 200B is stored in the communication buffer. Monitoring data B is stored.

  The control unit 210 of the network device 200A performs relay processing triggered by writing of monitoring data to the communication buffer in the first communication I / F unit 220 (in other words, reception of monitoring data from the connected IO network 30). 2642a is executed. As shown in FIG. 5, in the relay process 2642a, the control unit 210 reads the monitoring data from the communication buffer in the first communication I / F unit 220 (FIG. 5A: S100), and sends the monitoring data to the monitoring data buffer 2622. The monitoring data is written (FIG. 5A: S110). For this reason, in this operation example, the monitoring data A is stored in the monitoring data buffer 2622 of the network device 200A. Similarly, the network device 200B executes the processing of S100 and S110 (see FIG. 5B), and the monitoring data buffer 2622 stores the monitoring data B. When the monitoring data is written to the monitoring data buffer 2622, the control unit 210 sets a first value (for example, not equalized) to a flag indicating whether or not equalization has been performed. , 0), a flag having the first value set is added to the monitoring data and written to the monitoring data buffer 2622.

  In the network device 200A, the control unit 210 executes the equalization / transfer processing 2642b triggered by the writing of the monitoring data to which the flag indicating that the equalization has not been performed is added to the monitoring data buffer 2622. FIG. 6 is a flowchart showing a flow of equalization / transfer processing 2642b executed by the control unit 210 of the network device 200 in accordance with the relay control program 2642. As shown in FIG. 6, in the equalization / transfer processing 2642b, the control unit 210 determines whether or not the own device is operating as an active system (step SA100). Specifically, the control unit 210 refers to the operation / standby flag stored in the volatile storage unit 262, and if the value of the flag indicates the active system, the own device operates as the active system. It is determined that If the determination result of step SA100 is “Yes”, the control unit 210 executes the process of step SA110. Conversely, if the determination result of step SA100 is “No”, the control unit 210 performs the process of step SA120. Execute the process. As described above, in this operation example, the network device 200A operates as an active system. Therefore, in the equalization / transfer processing 2642b executed by the control unit 210 of the network device 200A, the determination result in step SA100 is “Yes”, and the processing in step SA110 is executed.

  In step SA110, the control unit 210 reads the monitoring data to which the flag indicating that the equalization has not been performed is added from the monitoring data buffer 2622 (FIG. 5A: S120), and indicates the transmission destination of the header of the monitoring data. The information is rewritten from the control device 100A to information indicating the network device 200B, and the monitoring data is transferred to the connected network device 200B through the third communication I / F unit 240 (FIG. 5A: S130). As described above, the monitoring data buffer 2622 of the network device 200A stores the monitoring data A as monitoring data to which a flag indicating that the equalization has not been performed is added. Therefore, in this operation example, the monitoring data A is transferred from the network device 200A to the network device 200B via the equalization cable 500.

  In the network device 200B, the control unit 210 executes the equalization / transfer processing 2642b when the third communication I / F unit 240 receives data transmitted via the equalization cable 500. . In the equalization / transfer processing 2642b executed by the control unit 210 of the network device 200B, the determination in step SA100 described above is performed. In the present operation example, since the network device 200B operates as a standby system, the determination result in step SA100 of the equalization / transfer processing 2642b executed by the control unit 210 of the network device 200B is “No”, and in step SA120 Processing is executed.

  In step SA120, the network device reception process shown in FIG. 7 is executed. In the network device reception process, the control unit 210 determines whether the data received via the equalization cable 500 is data destined for the own device (step S601). Specifically, the control unit 210 refers to the transmission destination of the header of the monitoring data stored in the third communication I / F unit 240 and determines whether or not the monitoring data is addressed to the own device. If the determination result in step S601 is “Yes”, the control unit 210 executes an equalization process (step S602). In step S602, the control unit 210 obtains the monitoring data received by the third communication I / F unit 240 from the third communication I / F unit 240 (FIG. 5B: S140), and uses the monitoring data. The corresponding monitoring data stored in the monitoring data buffer 2622 (monitoring data having the same transmission source and the same identifier as the monitoring data acquired in S140 in FIG. 5B) is overwritten (FIG. 5B ): S150), the flag assigned to the monitoring data is rewritten to a second value (for example, 1) indicating that the equalization has been completed. As a result, the monitoring data stored in the monitoring data buffer 2622 of the network device 200B is updated from the monitoring data B to the monitoring data A.

  When the control unit 210 of the network device 200B completes the equalization of the monitoring data as described above, the control unit 210 notifies the network device 200A of the completion of the equalization via the equalization cable 500 (step S603). The control unit 210 of the network device 200 </ b> A updates the monitoring data flag transferred in S <b> 130 of FIG. 5A to the second value when the notification is received. As a result of the above operation, the monitoring data buffer 2622 of each of the network device 200A and the network device 200B stores the monitoring data A, and the monitoring data A is given a flag indicating equalization. It becomes a state.

  The control unit 210 of the network device 200A restarts the relay processing 2642a when the flag added to the monitoring data stored in the monitoring data buffer 2622 is updated to a value indicating equalization. Each process of S160 and S170 of 5 (A) is executed. In the process of S <b> 160, the control unit 210 reads monitoring data to which a flag indicating equalization has been assigned from the monitoring data buffer 2622. Then, in the process of S170, the network device transmission process shown in FIG. 8 is executed.

  In the network device transmission process shown in FIG. 8, the control unit 210 reads out the monitoring data to which the flag indicating equalization has been added from the monitoring data buffer 2622, as in step SA <b> 100 described above. It is determined whether the own apparatus is operating as an active system (step S701). If the determination result in step S701 is “Yes”, the control unit 210 executes the processing from step S702 onward. Conversely, if the determination result in step S701 is “No”, the control unit 210 performs step S703. Execute the process. As described above, in this operation example, the network device 200A operates as an active system. For this reason, in the network device transmission process executed by the control unit 210 of the network device 200A, the determination result in step S701 is “Yes”, and the processing from step S702 onward is executed. In step S702, the control unit 210 determines whether or not the network device connection bus 60A is normal.

  Since the network device connection bus 60A is normal in this operation example, the determination result in step S702 is “Yes”, and the control unit 210 executes the process in step S703. In step S703, the control unit 210 writes the monitoring data read out in the process of S160 in the communication buffer in the second communication I / F unit 230, and transmits the communication data to the connection destination control device 100A. Through the processing in step S703, the monitoring data A is transferred from the network device 200A to the control device 100A as indicated by the alternate long and short dash line in FIG.

  In the network apparatus 200B, the relay process 2642a is restarted when the notification of equalization completion is transmitted (step S603), and the processes of S160 and S170 of FIG. 5B are executed. In this operation example, since the network device 200B operates as a standby system, in the network device transmission process executed by the control unit 210 of the network device 200B, the determination result of step S701 is “No”, and the processing of step S703 is executed. Through the processing in step S703, the monitoring data A is transferred from the network device 200B to the control device 100B.

  Since the notification can be transmitted and received sufficiently faster than the transmission and reception of the monitoring data, the update of the flag in each of the network device 200A and the network device 200B is executed substantially synchronously, and S160 and S170 These processes are also executed substantially synchronously. For this reason, the transmission of the monitoring data A from the network device 200A to the control device 100A and the transmission of the monitoring data A from the network device 200B to the control device 100B are executed almost synchronously.

  Next, the operation of the control device 100 will be described with reference to FIGS. 9 and 10. When receiving the monitoring data transmitted from the network device connection bus 60A, the first communication I / F unit 120 of the control device 100A writes the received monitoring data in the communication buffer in the first communication I / F unit 120. . Similarly, in the control device 100B, the monitoring data received from the network device connection bus 60B is written in the communication buffer in the first communication I / F unit 120 of the control device 100B.

  The control unit 110 of the control device 100A executes the arithmetic processing 1542a when the monitoring data is written to the communication buffer in the first communication I / F unit 120. As shown in FIG. 9, in the calculation process 1542a, the control unit 110 reads the monitoring data from the communication buffer in the first communication I / F unit 120 (FIG. 9 (A): S200), and calculates the monitoring data. Then, calculation data A based on the calculation result is generated, and the calculation data A is written to the calculation data buffer 1522 (FIG. 9A: S210). The same identifier as that given to the header of the monitoring data that is the basis of the calculation data A is given to the header of the calculation data A. Similarly, the control device 100B executes the processing of S200 and S210 (see FIG. 9B), and the operation data B is stored in the operation data buffer 1522. Specifically, the control unit 110 of the control device 100B executes the arithmetic processing 1542a in response to the writing of the monitoring data to the communication buffer in the first communication I / F unit 120. Similarly to the header of the calculation data A, the identifier assigned to the header of the monitoring data that is the basis of the calculation data B is also assigned to the header of the calculation data B generated by the control device 100B. For this reason, the same identifier is given to the headers of both the calculation data A and the calculation data B generated from one monitoring data. Note that when writing calculation data to the calculation data buffer 1522, the control unit 110 sets a first value (for example, not equalized) to a flag indicating whether or not equalization has been performed. , 0) is set, a flag having the first value set is added to the calculation data and written to the calculation data buffer 1522.

  In the control device 100A, the control unit 110 executes the equalization process 1542b triggered by the writing of the calculation data to which the flag indicating that the equalization has not been performed is added to the calculation data buffer 1522. FIG. 10 is a flowchart showing the flow of the equalization process 1542b. As shown in FIG. 10, in the equalization process 1542b, the control unit 110 first determines whether or not the own apparatus is operating as an active system (step SA200). Specifically, the control unit 110 refers to the operation / standby flag stored in the volatile storage unit 152, and if the value of the flag indicates a value indicating the active system, the control device 110 operates as the active system. It is determined that If the determination result in step SA200 is “Yes”, the control unit 110 executes the process in step SA210. Conversely, if the determination result in step SA200 is “No”, the control unit 110 performs the process in step SA220. Execute the process. As described above, in this operation example, the control device 100A operates as an active system. For this reason, in the equalization process 1542b executed by the control unit 110 of the control device 100A, the determination result in step SA200 is “Yes”, and the process in step SA210 is executed.

  In step SA210, the control unit 110 reads out the calculation data to which the flag indicating that the equalization has not been performed is added from the calculation data buffer 1522 (FIG. 9A: S220), and the calculation data is read from the second communication I / F The data is transferred to the connected control device via the unit 130 (FIG. 9A: S230). As described above, the calculation data A is stored in the calculation data buffer 1522 of the control device 100A as calculation data to which a flag indicating that equalization has not been performed is added. For this reason, in this operation example, the operation data A is transferred from the control device 100A to the control device 100B via the equalization cable 400.

  In the control device 100B, the control unit 110 executes the equalization process 1542b when the second communication I / F unit 130 receives data transmitted via the equalization cable 400. In the equalization process 1542b executed by the control unit 110 of the control device 100B, the above-described determination in step SA200 is performed. In this operation example, since the control device 100B operates as a standby system, the determination result in step SA200 of the equalization processing 1542b executed by the control unit 110 of the control device 100B is “No”, and the processing in step SA220 is performed. Executed.

  In step SA220, equalization of the operation data is executed. More specifically, in step SA220, the control unit 110 acquires the calculation data received by the second communication I / F unit 130 from the second communication I / F unit 130 (FIG. 9B: S240). ), The corresponding calculation data stored in the calculation data buffer 1522 is overwritten with the calculation data (the calculation data acquired in S240 of FIG. 9B and the identifier assigned to the header) (FIG. 9B). 9 (B): S250), the flag assigned to the calculation data is rewritten to a second value (for example, 1) indicating that the equalization has been completed. As a result, the calculation data stored in the calculation data buffer 1522 of the control device 100B is updated from the calculation data B to the calculation data A.

  When the control unit 110 of the control device 100B completes the equalization of the monitoring data as described above, the control device 100B notifies the control device 100A of the completion of the equalization via the equalization cable 400 (step SA230). The control unit 110 of the control device 100A updates the calculation data flag transferred in S230 of FIG. 9A to the second value upon receiving the notification. As a result of the above operation, the calculation data A is stored in the calculation data buffer 1522 of each of the control device 100A and the control device 100B, and a flag indicating equalization is given to the calculation data A. It becomes a state.

  The control unit 110 of the control device 100A restarts the arithmetic processing 1542a in response to the flag added to the arithmetic data stored in the arithmetic data buffer 1522 being updated to a value indicating equalization. Each process of S260 and S270 of 9 (A) is executed. In the process of S260, the control unit 110 reads out the calculation data to which the flag indicating equalization has been assigned from the calculation data buffer 1522. In the process of S270, information indicating the control target device that is the transmission destination is added to the calculation data and written to the communication buffer in the first communication I / F unit 120.

The arithmetic data written in the communication buffer in the first communication I / F unit 120 in this way is in the reverse order of the same communication path as the monitoring data (that is, the control device 100A → the network device connection bus 60A → the network device 200A → IO). Network 30-> control target device), and reaches the destination of the calculation data. The controlled device executes processing according to the calculation data. Thereby, the operation control of the device to be controlled is realized.
The above is the operation when the network device connection bus 60A is normal.

(B-2: Operation when the network device connection bus 60A is not normal)
Next, as shown in FIG. 11, an operation when the network device connection bus 60A is not normal (that is, the network device connection bus 60A is disconnected) will be described. In this case, the determination result in step S702 of the network device transmission process (see FIG. 8) executed by the network device 200A is “No”. Since the determination result in step S702 is “No”, the control unit 210 of the network device 200A writes the monitoring data read in the process of S160 to the communication buffer in the third communication I / F unit 240, and connects to the network of the connection destination. It transmits to the apparatus 200B (step S704). In step S704, the control unit 210 does not rewrite information indicating the transmission destination of the monitoring data header. Therefore, the information indicating the transmission destination of the header of the monitoring data transferred from the network device 200A to the network device 200B via the equalization cable 500 remains the information indicating the control device 100A.

  As described above, the control unit 210 of the network device 200B executes the equalization / transfer processing 2642b when the monitoring data is written in the communication buffer in the third communication I / F unit 240. In the present operation example, since the network device 200B operates as a standby system, the determination result in step SA100 is “No”, and the control unit 210 executes the network device reception process in step SA120. Here, since the information indicating the transmission destination of the header of the monitoring data received via the equalization cable 500 is the information indicating the control device 100A instead of the own device, the determination result in step S601 of the network device reception process shown in FIG. Becomes “No”, and the control unit 210 executes the process of step S604. In step S604, the control unit 210 reads the monitoring data stored in the communication buffer in the third communication I / F unit 240 (FIG. 5: S140), and passes the monitoring data through the fourth communication I / F unit 250. The data is transferred to the connection destination control device 100A (FIG. 5B: S180). As a result of this operation, the monitoring data transmitted from the IO slave device to the control device 100A is transmitted to the network device 200A, the equalization cable 500, the network device 200B, and the redundant connection bus 600 as shown by the one-dot chain line in FIG. And transmitted to the control device 100A.

With the above operation example, the monitoring data A is transmitted from the network device 200A to the control device 100A, and the monitoring data A is also transmitted from the network device 200B to the control device 100B.
The above is the operation when the network device connection bus 60A is not normal.

  In the present embodiment, even if the network device connection bus 60A that connects the active control device (ie, the control device 100A) and the active network device (ie, the network device 200A) is disconnected, the IO Since the monitoring data transmitted from the slave device to the control device 100A is transmitted to the control device 100A via the network device 200A, the equalization cable 500, the network device 200B, and the redundant connection bus 600, the control device There is no need to switch the active / standby system for 100. Therefore, according to the present embodiment, the frequency of switching between the active system and the standby system can be reduced as compared with the conventional redundant control system 3 (see FIG. 19).

  In addition, in the conventional redundant control system 3 shown in FIG. 19, since the control device (that is, the control device 10A and the control device 10B) performs equalization of the monitoring data, when the data amount of the monitoring data increases, Due to the equalization, the processing load of the control device is increased, and there is a possibility that the high-speed execution of the original calculation may be hindered. On the other hand, in this embodiment, the equalization of the monitoring data is executed by the network device 200A and the network device 200B by communication via the equalization cable 500. Therefore, even if the amount of monitoring data transferred to the control device 100A and the control device 100B increases due to an increase in the number of IO slave devices connected to the IO network 30, the control device 100A and the control device 100B Such processing load is not increased by the equalization, and there is no trouble in executing the original calculation.

Second Embodiment
Since the configuration of the redundant control system 1 of the present embodiment is the same as that of the redundant control system 1 of the first embodiment, the same components are denoted by the same reference numerals, and in the following description, FIGS. (However, FIG. 4 and FIG. 8 are excluded). The difference between the redundant control system 1 of the first embodiment and the redundant control system 1 of the second embodiment is that the control device 100 has a data received list in the volatile storage unit 262 and the network device transmission. The processing content of the processing (FIG. 5: S170) and the processing content of the control device reception processing (FIG. 9: S200). These will be described below.

  FIG. 12 is a flowchart showing the flow of the network device transmission process of the present embodiment. The control unit 210 of the network device 200A performs the network device transmission process in response to the completion of the process of reading the monitoring data to which the flag indicating equalization is given from the monitoring data buffer 2622 (FIG. 5: S160). Start. The control unit 210 writes the monitoring data in the communication buffer in the second communication I / F unit 230 and transmits it to the control device 100A (step S1201). After the processing of step S1201 is completed, the control unit 210 writes the same monitoring data as the monitoring data written in the communication buffer in the second communication I / F unit 230 to the communication buffer in the third communication I / F unit 240, The data is transmitted to the network device 200B (step S1202).

  In the network device transmission process of the first embodiment, monitoring data is transmitted to either the control device 100A or the network device 200B depending on whether the network device connection bus 60A is normal. In the network device transmission process, monitoring data is transmitted to both the control device 100A and the network device 200B regardless of whether the network device connection bus 60A is normal. Therefore, if disconnection has not occurred in the network device connection bus 60A, the control device 100A receives two pieces of monitoring data having the same contents.

  FIG. 13 is a flowchart illustrating a flow of control device reception processing executed by the control device 100. When the first communication I / F unit 120 or the third communication I / F unit 140 receives the monitoring data, the control unit 110 of the control device 100A starts the control device reception process. In this control device reception process, the control unit 110 of the control device 100A refers to the data received list stored in the volatile storage unit 262 of the control device 100A, and the received data is registered in the data received list. It is determined whether or not (step S1301). The data received list is information indicating the transmission source of the monitoring data given to the header of the monitoring data and an identifier uniquely indicating the monitoring data (for example, a time stamp when the IO slave device generates the monitoring data) And a sequence number of the monitoring data).

  If the determination result in step S1301 is “No”, the control device 100A refers to the header of the received monitoring data and registers information related to the monitoring data in the data received list (step S1302). Then, the control device 100A executes a reception process that performs a calculation related to the monitoring data (step S1303). On the other hand, if the determination result in step S1301 is “Yes”, the control device 100A discards the received monitoring data (step S1304).

  FIG. 14 is a diagram illustrating a flow of transmission of monitoring data transmitted from the IO slave device to the control device 100A when the network device connection bus 60A is normal. In FIG. 14, the flow of the monitoring data is indicated by a one-dot chain line. The monitoring data addressed to the control device 100A generated by the IO slave device (not shown) is equalized from the first transmission path transmitted from the network device 200A to the control device 100A via the network device connection bus 60A and from the network device 200A. The data is transmitted through both the cable 500, the network device 200B, and the second transmission path transmitted to the control device 100A via the redundant connection bus 600. The control unit 110 of the control device 100A refers to the data received list and discards the received monitoring data. In the present embodiment, the monitoring data via the first transmission path reaches the control device 100A earlier by the amount not passing through the network device 200B, and the control device 100A triggers the reception of the monitoring data. The information indicating the transmission source and the identifier uniquely indicating the monitoring data are registered in the data received list. When the control device 100A receives the monitoring data transmitted along the second transmission path, the control device 100A discards the monitoring data, and the calculation based on the same monitoring data is not performed repeatedly. When the network device connection bus 60A is disconnected, the same monitoring data transmission flow as that in FIG. Similar to the redundant control system 1 of the first embodiment, the redundant control system 1 of the present embodiment also has a network device connection bus (in this embodiment) that connects the active control device 100 and the active network device 200. By disconnecting the network device connection bus 60A), there is no need to switch the active system / standby system.

  Also in the present embodiment, the same effect as in the first embodiment can be obtained by disconnecting the network device connection bus. Furthermore, unlike the first embodiment, in this embodiment, the processing load on the active network device 200 is reduced by the amount that the determination as to whether the connection destination network device connection bus is normal is not performed on the network device 200 side. Is done. On the other hand, in the present embodiment, since it is necessary to determine whether or not the received monitoring data has been received, the processing load of the active control device 100 is increased compared to the first embodiment. Therefore, when priority is given to reducing the processing load of the network device 200, the second embodiment may be adopted, and vice versa, the first embodiment may be adopted.

<Modification>
Although the first and second embodiments of the present invention have been described above, it goes without saying that the following modifications may be added to these embodiments.
(1) In each of the embodiments described above, a push in which monitoring data is transmitted and stored via the equalization cable 500 from the active network device 200 of the network devices 200A and 200B to the standby network device 200. The case where the equalization of the monitoring data is realized by the type of data communication has been described. However, the monitoring data is acquired by pull-type data communication that causes the standby network device 200 to execute processing for acquiring the monitoring data from the active network device 200 via the equalization cable 500 and updating the monitoring data of the own device. Equalization may be realized. Similarly, the control device 100A and the control device 100B may realize equalization of operation data by pull-type data communication.

(2) In each of the above embodiments, the application example of the present invention to the gateway device that transfers the monitoring data collected from the IO slave device to the control device 100 has been described. However, the application target of the present invention is not limited to the gateway device, and may be another type of relay device such as a router, a repeater, or a switching hub. Further, the network connected to the relay device of the present invention is not limited to a control network such as an IO network or a serial bus, but is a general information system that mediates data communication according to a general-purpose communication protocol such as TCP. It may be a network. In short, it is connected to a control device that collects monitoring data and executes operations using the monitoring data, and a network connected to a device that outputs the monitoring data, and controls the data received via the network. The present invention can be applied to any relay device that transfers data to the device.

(3) A mode in which a network device (relay device) and a control device included in the communication system of each of the above embodiments are provided alone (that is, manufactured and sold) may be employed. The network device or control device is replaced with the network device or control device in the conventional redundant control system, and the first equalization cable serving as the communication device between relay devices and the communication device between the control devices are used. By connecting the network device and the control device as shown in FIG. 1 with the second equalization cable and two redundant connection buses, the conventional redundant control system functions as the communication system of each of the above embodiments. It is because it becomes possible to make it.

(4) In each of the above-described embodiments, the relay processing 2642a and the equalization / transfer processing 2642b that clearly show the features of the present invention are realized by software. However, each of the relay unit that executes the relay process 2642a and the equalization / transfer unit that executes the equalization / transfer process 2642b is configured by an electronic circuit, and these electronic circuits are combined to form the network device 200 of each of the above embodiments. May be configured. Similarly, each of the arithmetic means and the equalization means for executing the respective processing of the arithmetic processing 1542a and the equalization processing 1542b that clearly show the features of the present invention is constituted by an electronic circuit, and these electronic circuits are combined to You may comprise the control apparatus 100 of embodiment. In each of the above embodiments, the equalization cable is used as the communication means between the control devices and the communication means between the relay devices. However, a wireless communication means such as a wireless LAN interface may be used as each of the communication means. The same applies to the connection bus. Further, when the network device 200A and the network device 200B are mounted in one housing, a bus connected to both devices may be used as a communication device between relay devices. The same applies to the inter-control device communication means.

(5) In each of the above embodiments, the monitoring data received via the connected network device 200 is used regardless of whether each of the control device 100A and the control device 100B is an active system or a standby system. Thus, the case where the calculation for device control is performed (that is, the application example of the present invention to the hot standby control system) has been described. However, the application target of the present invention is not limited to a hot standby control system, and the present invention may be applied to a warm standby control system. The warm standby control system is the same as the hot standby control system in that one of the redundant control devices becomes the active system and executes the above calculation, and the other becomes the standby system to prepare for failure of the active system. However, a difference is that the above calculation is not executed in the standby control device. In the above embodiment, the standby network device also writes the monitoring data received by the first communication I / F unit 220 into the monitoring data buffer 2622 (FIG. 5B: each processing of S100 and S110). However, this processing may be omitted in the standby network device. This is because the monitoring data written by the monitoring data buffer 2622 by the processes of S100 and S110 of FIG. 5B is overwritten by the process of step SA120 of the equalization / transfer process 2642b. Similarly, in the standby control device, the processing (FIG. 9B: each processing of S200 and S210) of writing the arithmetic data that has been subjected to the arithmetic processing 1542a into the arithmetic data buffer 1522 may be omitted. This is because the calculation data written by the calculation data buffer 1522 by the processes of S200 and S210 in FIG. 9B is overwritten by the process of step SA220 of the equalization process 1542b.

(6) In the first embodiment, the network device 200 has determination means for determining whether or not the network device connection bus connected to the own device is normal. You may have the said determination means. By providing the determination unit in the control device 100, the processing load on the control device 100 increases, but the processing load on the network device 200 can be reduced. Therefore, the aspect in which the determination unit is provided in the control device 100 is effective when it is desired to reduce the processing load of the network device 200. Further, both the network device 200 and the control device 100 may have a determination unit. In this case, it is effective in that determination can be performed even if one of the determination units of the network device 200 and the control device 100 is out of order. In the aspect in which the determination unit is provided in the control device 100, the active control device 100 receives the determination result data indicating the determination result of the determination unit via the redundant connection bus. The standby network device 200 may execute the process of transmitting the determination result data received via the redundant connection bus via the equalization cable 500. The network device 200 may be transmitted. Further, the active control device 100 executes a process of transmitting the determination result data to the standby control device 100 via the equalization cable 400, and the standby control device 100 has the equalization cable 400. The determination result data received via the network system 200 is transmitted to the active network device 200 via the redundant connection bus (or the active network device 200 via the standby network device 200 and the equalization cable 500). Processing to be transmitted).

(7) In the first embodiment, the network device 200 has the determination means for determining whether the network device connection bus connected to the own device is normal. A determination device different from the network device 200 may be provided, and the determination device may serve as the determination unit. This aspect is effective when the processing capacity of both the control device 100 and the network device 200 is not sufficient.

(8) In the first embodiment, the network device connection bus (that is, the network device) that connects the active control device 100 (that is, the control device 100A) and the active network device 200 (that is, the network device 200A). When the connection bus 60A) is disconnected, the monitoring data is transmitted to the active control device 100 via the active network device 200, the equalization cable 500, the standby network device 200, and the redundant connection bus 600. However, as indicated by the alternate long and short dash line in FIG. 15, the monitoring data is transferred to the active control device via the active network device 200, the redundant connection bus 700, the standby control device 100, and the equalization cable 400. 100 may be transmitted. In order to realize this aspect, the control unit 210 of the network device 200A executes the process of transferring the monitoring data to the control device 100B via the redundant connection bus 700 when the disconnection of the network device connection bus 60A is detected. Further, the control unit 110 of the control device 100B is caused to execute processing for transferring the monitoring data received from the network device 200A via the redundant connection bus 700 to the control device 100A via the equalization cable 400. do it. This aspect is effective not only when the equalization cable 500 is cut but also when the equalization cable 500 does not exist. This aspect is applicable to the second embodiment, and is also effective when the equalization cable 500 is cut or does not exist. If the equalization cable 500 does not exist, for example, the control device 100 may be made to equalize the monitoring data as in the conventional redundancy control system 3.

(9) In the second embodiment, the data received list stored in the volatile storage unit 152 by the control device 100 includes information indicating the transmission source of the monitoring data attached to the header of the monitoring data and the monitoring Although an identifier uniquely indicating data is registered, any data received list may be used as long as filtering processing for preventing the same monitoring data as the already received monitoring data from being received again can be performed. For example, the filtering process may be executed by storing the entire received monitoring data. In this case, a more accurate filtering process can be executed as compared with the second embodiment.

(10) As shown in FIG. 16, the equalization cable 400 may be omitted. In the redundancy control system 2 of FIG. 16, the components other than the equalization cable 400 are the same as those in the redundancy control system 1 of the first embodiment, and therefore the same components are denoted by the same reference numerals. The redundancy control system 2 is different from the redundancy control system 1 only in that the equalization cable 400 is not provided. The equalization of the operation data may be performed by communication via the network device connection bus 60A, the network device 200A, the equalization cable 500, the network device 200B, and the network device connection bus 60B, for example. .

  FIGS. 17 and 18 are diagrams showing a flow of monitoring data transmitted from the IO slave device to the control device 100A in the redundant control system 2 of this aspect. As shown in FIG. 17, when the network device connection bus 60A is normal, the monitoring data is transmitted to the control device 100A via the IO network 30, the network device 200A, and the network device connection bus 60A. When the network device connection bus 60A is disconnected, as shown in FIG. 18, the monitoring data is transmitted via the IO network 30, the network device 200A, the equalization cable 500, the network device 200B, and the redundant connection bus 600. It is transmitted to the control device 100A. In addition, as in the second embodiment, monitoring data is transmitted from the network device 200A to both the network device connection bus 60A and the equalization cable 500 regardless of whether the network device connection bus 60A is normal. In this case, it is needless to say that it is necessary to store the data received list in the control device 100A.

(11) In the above embodiments, the monitoring data received from the IO network 30 is equalized in the active and standby network devices 200, and the equalized monitoring data is transferred to the active control device 100. Explained. However, after the monitoring data received from the IO network 30 is transferred to the active control device 100, the monitoring data is transferred to the standby network device 200 via the equalization cable 500 in order to equalize the monitoring data. It is also possible to cause the active network device 200 to execute the process of transferring to the network. Further, only when the monitoring data cannot be transferred to the active control device 100, the active network device 200 executes the process of transferring the monitoring data to the standby network device 200 via the equalization cable 500. In the standby network device 200, the monitoring data received via the equalization cable 500 is equalized with the monitoring data received via the IO network 30, and the monitoring is performed via the redundant connection bus. Processing for transferring data to the active control device 100 may be executed. In the first embodiment, it is determined whether or not communication with the active control device 100 is possible. When it is determined that communication is possible, the monitoring data is transferred to the active control device 100. When the process is impossible, the active network apparatus 200 is caused to execute a process of transferring the monitoring data to the standby network apparatus 200 via the equalization cable 500. However, the above determination is omitted and the monitoring data is transferred to the active control device 100. If the transfer fails, the monitoring data is transferred to the standby network device 200 via the equalization cable 500. The active network device 200 may execute the processing to be performed.

(12) In each of the above embodiments, the case where the network to which the network apparatus 200 is connected is the IO network 30 has been described. However, the network may be a control network to which another controller is connected. A network including both may be used. In such an aspect, data to be transferred to the control device 100 by the network device 200 is not limited to monitoring data transmitted from an IO slave device such as a sensor, and arithmetic data transmitted from other controllers is also transferred. May be eligible. When calculation data transmitted from another controller is to be transferred by the network device 200, the control device 100 generates new calculation data based on the calculation data, and the control target device is generated according to the new calculation data. Is controlled.

1, 2, 3 ... Redundant control system, 10A, 10B, 100, 100A, 100B ... Control device, 20A, 20B, 200, 200A, 200B ... Network device, 110, 210 ... Control unit, 120, 220 ... First Communication I / F unit, 130, 230 ... Second communication I / F unit, 140, 240 ... Third communication I / F unit, 250 ... Fourth communication I / F unit, 150, 260 ... Storage unit, 152, 262 ... volatile storage unit, 1522, 2622 ... monitoring data buffer, 154, 264 ... non-volatile storage unit, 1542 ... control program, 2642 ... relay control program, 1542a ... arithmetic processing, 2642a ... relay processing, 1542b ... equalization processing 2642b ... Equalization / transfer processing, 160, 270 ... Bus, 30 ... IO network, 30 '... Network, 40, 400, 50 ... equalization cable, 60A, 60B ... network device connection bus, 600, 700 ... redundant connection bus.

Claims (14)

In a control system that collects monitoring data from devices connected to the network and performs control based on the monitoring data,
First and second control devices, one of which is an active system and the other is a standby system;
It is connected to the network and connected to the first control device, and if the first control device is an active system, it becomes an active system, and if the first control device is a standby system, it becomes a standby system. A first relay device;
Connected to the network and connected to the second control device. If the second control device is an active system, it becomes an active system, and if the second control device is a standby system, it becomes a standby system. A second relay device;
Redundant communication means for mediating communication between the first control device and the second relay device and mediating communication between the second control device and the first relay device;
Inter-relay device communication means for mediating communication between the first relay device and the second relay device;
Have
The active relay device is
Of the first processing for transferring the monitoring data received via the network to the active control device and the second processing for transferring the monitoring data to the standby relay device via the inter-relay communication means Performing at least the first process;
The standby relay device is:
Transfer monitoring data received via the inter-relay device communication means to the active control device via the redundant communication means,
The active control device is:
The control system characterized in that the control is performed based on either monitoring data received from the active relay device or monitoring data received from the standby relay device via the redundant communication means.   2. The control according to claim 1, wherein each of the first and second relay apparatuses performs equalization of monitoring data received from the network by communication via the inter-relay apparatus communication unit. system. The control system according to claim 1, wherein the active relay device executes the second process when monitoring data cannot be transferred by the first process. The active relay device executes both the first process and the second process,
Whether the active control device has already received each of the monitoring data transferred from the connected relay device and the monitoring data transferred from the standby relay device via the redundant communication means. The received control data is discarded if it has been received, and the control is executed based on the received monitor data if not received. 2. The control system according to 2. Inter-control device communication means for mediating communication between the first and second control devices;
The operating control device generates calculation data based on the received monitoring data,
Each of said 1st and 2nd control apparatus equalizes the said arithmetic data by communication via the said inter-control apparatus communication means. Any one of Claims 1-4 characterized by the above-mentioned. The control system according to claim 1. In a control system that collects monitoring data from devices connected to the network and performs control based on the monitoring data,
First and second control devices, one of which is an active system and the other is a standby system;
It is connected to the network and connected to the first control device, and if the first control device is an active system, it becomes an active system, and if the first control device is a standby system, it becomes a standby system. A first relay device;
Connected to the network and connected to the second control device. If the second control device is an active system, it becomes an active system, and if the second control device is a standby system, it becomes a standby system. A second relay device;
Redundant communication means for mediating communication between the first control device and the second relay device and mediating communication between the second control device and the first relay device;
Communication means between control devices that mediates communication between the first control device and the second control device;
Have
The active relay device is
Of the first process of transferring the monitoring data received via the network to the control device of the connection destination and the second process of transferring the monitoring data to the standby control device via the redundant communication means, Performing at least the first process;
The standby control device includes:
Transfer monitoring data received from the active relay device via the redundant control communication means to the active control device via the inter-control device communication means,
The active control device is:
A control system that performs the control based on any one of monitoring data received from the active relay device and monitoring data received from the standby control device via the inter-control device communication means. . The operating control device generates calculation data based on the received monitoring data,
The control system according to claim 6, wherein each of the first and second control devices equalizes the calculation data by communication via the inter-control device communication unit.   The control system according to claim 6 or 7, wherein the active relay device executes the second process when monitoring data cannot be transferred by the first process. The active relay device executes both the first process and the second process,
The active control device has already received each of the monitoring data transferred from the connected relay device and the monitoring data transferred from the standby control device via the inter-control device communication means. The received control data is discarded if received or not, while the control is executed based on the received monitor data if not received. Item 8. The control system according to Item 7. Inter-relay device communication means for mediating communication between the first and second relay devices;
Each of said 1st and 2nd relay apparatus equalizes the monitoring data received from the said network by communication via the said inter-relay apparatus communication means. The control system according to claim 1. Connected to one of the first and second control devices, one of which is the active system and one of which is the standby system, via a communication device between control device relay devices, and a device for transmitting monitoring data In a relay device connected to a connected network,
Connected to the other of the first and second control devices via the redundant communication means, and connected to the other relay device connected to the other control device via the relay device communication means,
First processing means for transferring monitoring data received via the network to a connection destination of the communication means between the control device relay devices;
Second processing means for transferring monitoring data received via the network to a connection destination of the inter-relay apparatus communication means;
And third processing means for transferring the monitoring data received via the inter-relay device communication means to the other control device via the redundant communication means,
When the connection destination of the communication device between the control device relay devices is an active system, a transfer is executed by at least the first processing device among the first processing device and the second processing device, and a standby system If it is, the transfer is performed by the third processing means. Connected to one of the first and second control devices, one of which is the active system and one of which is the standby system, via a communication device between control device relay devices, and a device for transmitting monitoring data In a relay device connected to a connected network,
Connected to the other of the first and second control devices via redundant communication means;
First processing means for transferring monitoring data received via the network to a connection destination of the communication means between the control device relay devices;
And second processing means for transferring the monitoring data received via the network to the other control device via the redundant communication means,
When the connection destination of the communication device between control device relay devices is an active system, at least transfer by the first processing device is performed. In a control device in a control system including two control devices in which one is an active system and the other is a standby system,
Connected to one of the two relay devices connected to the network to which the device for transmitting the monitoring data is connected, via the communication device between the control device relay devices, and connected to the other via the redundant communication device,
First processing means for performing the control based on monitoring data received from a connection destination of the communication means between the control device relay devices;
Second processing means for performing the control based on monitoring data received from a connection destination of the redundant communication means,
In the case of an active system, the control is performed by one of the first processing unit and the second processing unit. In a control device in a control system that includes two control devices connected to each other via communication means between the control devices while one side becomes an active system and performs control, and the other becomes a standby system.
Connected to one of the two relay devices connected to the network to which the device for transmitting the monitoring data is connected, via the communication device between the control device relay devices, and connected to the other via the redundant communication device,
First processing means for performing the control based on monitoring data received from a connection destination of the communication means between the control device relay devices;
Second processing means for performing the control based on monitoring data received from a connection destination of the inter-control device communication means;
And third processing means for transferring the monitoring data received from the connection destination of the redundant communication means to the other control device via the inter-control device communication means,
When it is an active system, the control is performed by one of the first processing means and the second processing means, and when it is a standby system, the third process is performed. A control device that performs transfer by means.

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