JP4966927B2 - Plant monitoring / control system and communication path detouring method - Google Patents

Description

  The present invention relates to a plant monitoring / control system including a plurality of devices that monitor or control the operation of a plant, and a communication path detouring method in a communication network that interconnects the devices.

  A plant monitoring / control system that monitors and controls the operation of plants such as power plants, factories, and water and sewage treatment plants is required to have high reliability and high availability such as continuous operation over a long period of time. Therefore, the monitoring devices and control devices constituting the plant monitoring / control system are often multiplexed, and the communication paths connecting these monitoring devices and control devices are also multiplexed (see, for example, Patent Document 1).

In such a multiplexed system, when a failure occurs in a communication channel in use, a technique of switching to use a communication channel without a failure has been put into practical use (for example, see Patent Document 2). ). In recent years, since the routing technology in communication networks has advanced, it has become possible to more easily configure a detour communication path that detours around a fault location (see, for example, Patent Document 3).
JP 9-442203 A Japanese Patent Laid-Open No. 2-7744 JP 2007-116751 A

  By the way, when looking at the current state of the plant monitoring / control system, not only is the information communication path used for the monitoring / control multiplexed, but also the computer for data processing and the monitoring are connected to the multiplexed communication path. A computer for data display is often connected. In addition, many of these computers are connected to a design / office network outside the plant monitoring and control system, and send and receive information to and from a personal computer for design and a server for business processing. Can do.

  Therefore, consider a communication network that uses such a design / office network as a redundant communication channel for multiplexed communication channels unique to the plant monitoring / control system. Since the communication network has an increased multiplicity of communication channels as compared to a unique communication channel of the plant monitoring / control system, the reliability of communication is improved. However, in this case, not all of the monitoring devices and control devices are connected to the design / office network, so the multiplicity of communication channels has not increased in a strict sense. Here, a multiplex communication path in a strict sense is a multiplex communication path in which a device included in the system is equally connected to any of the multiplex communication paths. Say.

  Incidentally, in the multiplex systems targeted by Patent Documents 1 to 3, a multiplex communication path in a strict sense is assumed. Therefore, the multiplicity of the communication path is not uniform for some or a majority of devices configured when an external communication network such as design / office work is added to the multiple communication path unique to the plant monitoring / control system. For multiplex communication networks, the switching of communication paths and the detour routing technique for fault locations disclosed in Patent Documents 1 to 3 cannot be applied as they are.

  In view of the above-mentioned problems of the prior art, the object of the present invention is to provide redundant communication that causes loss of multiplicity in a strict sense in a unique communication path of a plant monitoring / control system having a predetermined multiplicity. Even if a route is added, a plant monitoring / control system and a communication route capable of forming a detour route for detouring a fault occurring in a system-specific communication route via the spare redundant communication route It is to provide a detour method.

  In order to achieve the above object, in the present invention, a plant monitoring / control system includes a plurality of devices that monitor or control the operation of the plant, and a first communication network unique to the system that interconnects the plurality of devices. And a configuration of a communication network in which at least two of the plurality of devices are connected to a second communication network that is redundant for the first communication network. To do.

  In such a configuration, a device connected to both the first and second communication networks is caused to function as a routing device. That is, the routing device generates a communication path communication confirmation table indicating whether or not communication is possible by transmitting and receiving a survival notification frame to and from other devices connected to the first communication network at a predetermined time period. When a communication frame not destined for the own device is received, whether or not communication from the own device to the destination device is possible via the first communication network with reference to the communication path communication confirmation table If it is determined that communication is not possible, the received communication frame is transmitted to another routing device different from the own device connected to the second communication network via the second communication network. To do.

  By the operation of the routing device as described above, even if communication between devices via the first communication network is impossible, a part of the communication route is bypassed to the second communication network. , The communication becomes possible.

  According to the present invention, even if a redundant redundant communication path that causes loss of multiplicity in a strict sense is added to a specific communication path of a plant monitoring / control system having a predetermined multiplicity. It is possible to provide a plant monitoring / control system and a communication path detouring method capable of forming a detour path for detouring a fault occurring in a system-specific communication path through the redundant redundant communication path. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an example of a configuration of a plant monitoring / control system according to an embodiment of the present invention. As shown in FIG. 1, a plant monitoring / control system 10 includes plant monitoring / control devices 21, 22, 23, operation monitoring HMI (Human Machine Interface) devices 24, 25, system management server devices 28, 29, and a storage device 27. And so on. These devices are connected to each other by duplex communication paths 13 and 14 so that they can communicate with each other. The plant monitoring / control devices 21 and 22, the operation monitoring HMI devices 24 and 25, and the system management server devices 28 and 29 each have a double configuration. The plant monitoring / control devices 21 and 22 are connected to each other by a communication path 15 for double operation.

  Here, the plant monitoring / control devices 21, 22, and 23 are configured to include various sensors and actuators in addition to the control computer, and the control computer detects the operation status of the plant via the sensors. In addition, the operation of the plant is controlled via the actuator. The operation monitoring HMI devices 24 and 25 are configured to include a computer, a keyboard, a control console, a display device, and the like, and display the operation status of the plant on the display device in a form that can be easily recognized by the operator. Various operation instruction information of the operator is accepted. The system management server devices 28 and 29 are constituted by general-purpose computers, and perform schedule control of plant operation, arithmetic processing on various data acquired from the plant monitoring / control devices 21, 22, and 23. Further, the system management server devices 28 and 29 are connected to the shared storage device 27 via the dedicated communication path 12.

  On the other hand, outside the plant monitoring / control system 10, for example, a communication path 11 which is a communication network for design and office work is provided in the same premises as the plant. The communication path 11 is connected to a design / office personal computer 26, a design / office server device 31, and the like. Further, operation monitoring HMI devices 24 and 25 and system management server devices 28 and 29 in the plant monitoring / control system 10 are connected to the communication path 11. Therefore, the manager of the design or office work may, for example, browse the data on the operation status of the plant or the data obtained by the system management server devices 28 and 29 through the design / office personal computer 26 or the like. It becomes possible.

  In such a configuration, the communication path 11 is a communication network for design and office work, and thus is an open communication network compared to the communication paths 13 and 14 in the plant monitoring / control system 10. Therefore, the communication path 11 is likely to cause a problem in terms of information security. However, for example, if the information security problem in the communication path 11 is cleared by setting an appropriate firewall or the like, the communication path 11 is It can be used as a spare redundant communication path for the communication paths 13 and 14 in the plant monitoring / control system 10.

  In the above description, the number and multiplicity of plant monitoring / control devices 21, 22, and 23, the number and multiplicity of operation monitoring HMI devices 24 and 25, the number and multiplicity of system management server devices 28 and 29, etc. The number is not limited to that shown in FIG. Further, the multiplicity of the communication paths 13 and 14 is not limited to double, and may be single. Further, the number of the design / office personal computer 26 and the design / office server device 31 are not particularly limited since they are not substantially involved in the present invention.

  Hereinafter, in the present embodiment, when a failure occurs in a part of the communication paths 13 and 14 and communication between the devices connected to the communication paths 13 and 14 becomes impossible, the communication path is detoured to the communication path 11. A method for performing communication will be described in detail.

  FIG. 2 is a diagram illustrating an example of a configuration of a communication path priority table for each device included in the plant monitoring / control system 10. As shown in FIG. 2, the communication channel priority table indicates which communication route is used when there are a plurality of communication channels when each device included in the plant monitoring / control system 10 communicates with another device. It is a table that defines whether to use it preferentially. For example, according to the communication path priority table in the example of FIG. 2, when the plant monitoring / control device 21 communicates with the plant monitoring / control device 22, the communication path 15 is used with the highest priority, and due to a failure or the like. When the communication path 15 cannot be used, the next priority communication path 13 is used. This situation is the same for other devices.

  In the following description, for each of the devices 21 to 25 and 27 to 29 included in the plant monitoring / control system 10, when it is not necessary to specify the type of the device, the description of the name is omitted. It is simply described as the device 21, the device 22, and the like. In addition, these apparatuses are substantially configured to include a computer or a data processing circuit similar to a computer, and the function is realized by the operation of the computer or the data processing circuit.

  FIG. 3 is a diagram showing an example of a routing device definition table for each communication path included in the plant monitoring / control system 10. Here, the routing device is a function of bypassing a part of the communication path to the communication path 11 outside the plant monitoring / control system 10 when communication is not possible between the devices included in the plant monitoring / control system 10. It is an apparatus having. Accordingly, the routing device is a device connected to any one of the communication channels 12, 13, 14, and 15 inside the plant monitoring / control system 10 and also connected to the external communication channel 11. Chosen from. In this case, all devices that satisfy the condition may be used as routing devices, or some devices (however, at least two devices) may be selected from the corresponding devices as routing devices.

  In the configuration of this embodiment (see FIG. 1), the devices 24, 25, 28, and 29 are connected to the internal communication paths 13 and 14 of the plant monitoring / control system 10 and are connected to the external communication path 11. Therefore, it can be a routing device. Therefore, the routing device definition table is as shown in FIG.

  Next, the communication path communication confirmation table will be described with reference to FIGS. Here, FIG. 4 is a diagram showing an example of the communication path communication confirmation table of the devices 24 and 28 when there is no failure in the communication path, and FIG. 5 is generated in the communication path inside the plant monitoring / control system 10. FIG. 6 is a diagram showing an example of the location of the fault, and FIG. 6 is a diagram showing an example of a communication path communication confirmation table of the devices 24 and 28 when a fault occurs in the location of the communication path shown in FIG.

  Each of the devices 21 to 25 and 27 to 29 included in the plant monitoring / control system 10 has communication channels 12, 13, and 14 for each of the communication channels 12, 13, 14, 15, and 11 in a predetermined time period. , 15 and 11, a predetermined survival notification frame is transmitted and received between the devices 21 to 25 and 27 to 29 connected thereto. Then, based on the success / failure of the transmission / reception of the survival notification frame, whether or not mutual communication is possible is confirmed, and a communication path communication confirmation table is generated.

  As shown in FIG. 4, when there is no failure in any communication path, for example, in the communication path communication confirmation table of the devices 24 and 28, for each communication path 12, 13, 14, and 11, A mark ◯ indicating that the transmission / reception frame has been successfully transmitted / received to / from the communication partner apparatuses 21 to 25 and 27 to 29 connected via the communication paths 12, 13, 14, and 11 is added.

  Here, it is assumed that each communication path 12, 13, 14, 15, 11 is a communication path of one segment, and the survival notification frame sent to the communication path of a certain segment is sent to the communication path of another segment. Shall not be forwarded. In addition, the devices 24 and 28 transmit and receive a survival notification frame to and from the device 26 (design / office PC) and the device 31 (design / office server device) not included in the plant monitoring / control system 10. Absent. In addition, the existence notification frame is not transmitted / received to / from apparatuses temporarily connected to the communication paths 12, 13, 14, and 15 for system maintenance and the like.

  Next, as illustrated in FIG. 5, it is assumed that a failure 41 has occurred in the communication paths 13 and 14 between the device 22 and the device 23. In this case, the device 24 cannot communicate with the devices 23, 28, and 29 via the communication paths 13 and 14. In addition, the device 28 cannot communicate with the devices 21, 22, 24, and 25 via the communication paths 13 and 14. Therefore, the communication path communication confirmation table of the devices 24 and 28 is as shown in FIG. In FIG. 6, a cross indicates that transmission / reception of the survival notification frame has failed and communication is impossible.

  The process of transmitting / receiving the survival notification frame and generating the communication path communication confirmation table will be separately described in detail as a communication path monitoring process with reference to FIG.

  Next, the communication path detour information table will be described with reference to FIGS. 7 is a diagram illustrating an example of the communication path detour information table of the devices 24 and 28, FIG. 8 is a diagram illustrating an example of the communication path communication confirmation table of the devices 21 and 23, and FIG. It is the figure which showed the example of the communication path detour information table of 21 and 23. FIG.

  The communication path detour information table is a communication path outside the plant monitoring / control system 10 (FIG. 5) when a communication frame is transmitted to a communication partner apparatus marked with an X in the communication path communication confirmation table. In this example, the table stores information for identifying a routing device used when detouring to the communication path 11).

  Incidentally, the communication path detour information table corresponding to the communication path communication confirmation table of the devices 24 and 28 shown in FIG. 6 is as shown in FIG. Also, the communication path detour information table corresponding to the communication path communication confirmation table shown in FIG. 8 is as shown in FIG.

  As described above, the communication path detour information table of each of the devices 21 to 25 and 27 to 29 is marked with “X” in the communication path communication confirmation table of the devices 21 to 25 and 27 to 29, and the devices 21 to 25 and 27 to 29 thereof. Are replaced by the device numbers of the routing devices (devices 24, 25, 28, 29) that can communicate via the respective communication paths 12, 13, 14, 15.

  Such a communication path detour information table represents the following two things. First, when the communication partner column of each communication channel 12, 13, 14, 15 is not marked with a circle and a device number is stored, communication is made with that communication partner via the communication channel. Secondly, when transmitting a communication frame to the communication partner, the communication frame is transmitted via a device (routing device) having the device number stored in the column. It is necessary to do.

  That is, the communication path detour information table of the device 21 (23) shown in FIG. 9 is transmitted from the device 21 (23) to the devices 23, 28, 29 (21, 22, 24, 25) via the communication paths 13, 14. When communication frames are transmitted to the devices 23, 28, 29 (21, 22, 24, 25), the device 24 (28), which is a routing device, is transmitted to the devices 23, 28, 29 (21, 22, 24, 25). It means that it is necessary to send via.

  As shown in FIG. 7, when the transmission source device (devices 24 and 28) is a routing device and communication with the destination device via the communication paths 13 and 14 is impossible, it passes through. The routing device is its own device (devices 24 and 28) itself.

  Next, the configuration of the normal device, the detour information management device, and the routing device will be described with reference to FIGS. 10 and 11. 10 is a diagram illustrating an example of the configuration of the communication processing unit in the normal device and the detour information concentration processing unit in the detour information management device, and FIG. 11 is a detour in the communication processing unit and the detour information management device in the routing device. It is the figure which showed the example of the structure of the information intensive processing part.

  The detour information management device 30 referred to here is one device selected from the devices 21 to 25 and 27 to 29, and the communication path communication confirmation from each of the devices 21 to 25 and 27 to 29 (normal device 20). The table 211 is collected, a communication path detour information table 212 and a routing table to be described later are generated, the generated communication path detour information table 212 is returned to each of the devices 21 to 25 and 27 to 29, and the routing table 215 is This is a device having a function of transmitting to the routing device 40. The detour information management device 30 may be the routing device 40. The normal device 20 is a device that is neither the detour information management device 30 nor the routing device 40 among the devices 21 to 25 and 27 to 29. However, the following functions of the normal device 20 are included in the detour information management device 30 and the routing device 40 as well.

  As illustrated in FIG. 10, the communication processing unit 200 of the normal device 20 includes functional blocks such as a communication path monitoring processing unit 201, a data transmission / reception processing unit 202, and a communication path detour information updating unit 203. Further, the detour information central processing unit 300a of the detour information management device 30 includes functional blocks such as a communication path detour information generation unit 301. The function of such a functional block is realized by a CPU (Central Processing Unit) included in each of the normal device 20 and the detour information management device 30 executing a predetermined program stored in the storage device.

  Here, the normal apparatus 20 generates the communication path communication confirmation table 211 of the own apparatus by performing transmission / reception of a survival notification frame with other normal apparatuses 20 according to the processing flow of the communication path monitoring processing unit 201. . A detailed processing flow of the communication path monitoring processing unit 201 will be described separately with reference to FIG.

  On the other hand, the detour information management device 30 confirms the communication path communication from the normal device 20 (including the case of the routing device 40) included in the plant monitoring / control system 10 according to the processing flow of the communication path detour information generation unit 301. The table 211 is collected, a communication path detour information table 212 for each normal device 20 is generated based on the collected communication path communication confirmation table 211, and the generated communication path detour information table 212 is transmitted to each normal device 20. A detailed processing flow of the communication path detour information generation unit 301 will be described separately with reference to FIG.

  Further, the normal device 20 receives the communication path detour information table 212 transmitted from the detour information management device 30 according to the processing flow of the communication path detour information update unit 203, and updates the communication path detour information table 212 of the own device. To do. A detailed processing flow of the communication path detour information update unit 203 will be described separately with reference to FIG.

  Further, the normal apparatus 20 refers to the communication path detour information table 212 and the communication path priority table 213 as processing of the data transmission / reception processing unit 202, and executes transmission / reception of a communication frame instructed by a higher-level communication application program. . The detailed processing flow of the data transmission / reception processing unit 202 will be described separately with reference to FIG.

  Next, as illustrated in FIG. 11, the communication processing unit 400 of the routing device 40 includes functions such as a communication path monitoring processing unit 201, a data transmission / reception processing unit 202, a communication path detour information update unit 203, and a frame detour transmission processing unit 204. Consists of blocks. Further, the detour information central processing unit 300 of the detour information management device 30 includes functional blocks such as the communication path detour information generation unit 301. The function of such a functional block is realized by a CPU (Central Processing Unit) included in each of the routing device 40 and the detour information management device 30 executing a predetermined program stored in the storage device.

  The configuration of the detour information concentration processing unit 300 generates a routing table 215 in the function of the communication path detour information generation unit 301 in the detour information concentration processing unit 300a of FIG. 10 and transmits the generated routing table 215 to the routing device 40. It corresponds to the one that the function to do is added. Further, the configuration of the communication processing unit 400 corresponds to a configuration in which a frame bypass transmission processing unit 204 is added to the configuration of the communication processing unit 200 of FIG.

  Here, the routing device 40 receives and stores the routing table 215 transmitted from the detour information management device 30 according to the processing flow of the frame detour transmission processing unit 204, and appropriately stores the received routing table 215. Then, the communication frame transmitted to the own apparatus is not routed to the communication path outside the plant monitoring / control system 10 (communication path 11 in the example of FIG. 1). A detailed processing flow of the frame bypass transmission processing unit 204 will be described separately with reference to FIG.

  Next, the configuration of the routing table will be described with reference to FIG. FIG. 12 is a diagram showing an example of the configuration of the routing table of the device 24. As shown in FIG. 12, the routing table communicates from the device (for example, device 24) via the communication path outside the plant monitoring / control system 10 (communication path 11 in the example of FIG. 1). It is a table showing whether or not communication with other devices 21 to 25, 28, 29 is possible using other routing devices (devices 25, 28, 29) connected to the road as relay devices. In FIG. 12, ◯ indicates that communication is possible, and x indicates that communication is not possible.

  The routing table 215 is generated by the communication path detour information generation unit 301 of the detour information management device 30. As can be seen from the configuration of the routing table 215 shown in FIG. It is easily generated from the confirmation table 211 and the routing device definition table 214.

  Hereinafter, with reference to FIGS. 13 to 17, details of processing in the normal device 20, the detour information management device 30, and the routing device 40 will be described.

  FIG. 13 is a diagram illustrating an example of a processing flow of a communication path monitoring process in the normal device 20 (including the case of the routing device 40 and hereinafter simply referred to as the device 20). As illustrated in FIG. 13, the communication path monitoring process (the process of the communication path monitoring processing unit 201) includes a process as a transmission apparatus and a process as a reception apparatus.

  The process as the transmission device of the communication path monitoring process is activated at a predetermined time (for example, 10 seconds) cycle. The device 20 generates a survival notification frame of the device itself (step S11), and broadcasts the generated survival notification frame to all monitored self-connected communication paths (step S12).

  The process as a receiving device of the communication path monitoring process is configured by two processes, one of which is activated by receiving a survival notification frame broadcast from another apparatus 20. That is, when receiving the existence notification frame (step S21), the device 20 acquires a transmission source address from the received existence notification frame (step S22), and resets a transmission source monitoring counter corresponding to the transmission source address (step S22). S23), the existence of the transmission source device is reflected in the communication path communication confirmation table 211 (step S24).

  In addition, other processing as the reception device of the communication path monitoring processing is activated at a predetermined time (for example, 10 seconds) cycle. The device 20 counts up the transmission source monitoring counter each time (step S25), and further determines whether or not the transmission source monitoring counter has exceeded a predetermined upper limit (step S26). As a result of the determination, if the transmission source monitoring counter does not exceed the predetermined upper limit (No in step S26), the processing is terminated without doing anything, but the transmission source monitoring counter exceeds the predetermined upper limit. If yes (Yes in step S26), it means that the existence notification frame has not been received for a predetermined time, and therefore the non-survival of the transmission source device is reflected in the communication path communication confirmation table 211 (step S27).

  FIG. 14 is a diagram illustrating an example of a processing flow of data transmission / reception processing in the apparatus 20. As shown in FIG. 14, the data transmission / reception processing (processing of the data transmission / reception processing unit 202) includes processing as a transmission device and processing as a reception device, and a handshake method is adopted for the data transmission / reception processing. ing. The handshake method is a method in which the transmission device receives a reception confirmation notification from the reception device with respect to transmission data and confirms the successful reception.

  In FIG. 14, the processing as the transmission device of the data transmission / reception processing is determined in advance for a predetermined time period (for example, 1 second, 10 seconds, 1 minute, etc. depending on the purpose) for the purpose of controlling the plant. Cycle). The device 20 first edits data to be transmitted, generates a communication frame (step S31), and sets a serial number in the communication frame (step S32).

  Here, the communication frame is configured by adding a transmission source address, a destination address, a serial number, the number of data, an error check / correction code, and the like to data to be transmitted. The serial number is used as information for identifying the communication frame.

  Next, the apparatus 20 refers to the communication path detour information table 212 and the communication path priority table 213, selects the highest priority communication path among the communication paths to which the destination apparatus is connected (step S33), and selects it. A communication frame is sent to the communication path that has been completed (step S34). At this time, when the communication path detour information table 212 for the selected communication path is referred to and direct communication with the destination apparatus is impossible via the communication path, the apparatus 20 uses the detour information as the detour information. The device number of the routing device 40 stored in the communication path detour information table 212 is added to the communication frame as route information.

  Next, the device 20 waits for a reception confirmation notification from the reception device, and when receiving the reception confirmation notification (Yes in step S35), ends the data transmission process. If the reception confirmation notification is not received even after a predetermined time has elapsed (No in step S35), the communication path priority table 213 is referred to, and if there is a next priority communication path (step (Yes in S36), the communication path is switched to the next priority communication path (step S37), the process returns to step S34, and the communication frame is transmitted to the next priority communication path. If there is no next priority communication path (No in step S36), the data transmission process is terminated.

  In FIG. 14, the processing as the receiving device of the data transmission / reception process is activated by receiving a communication frame of data transmitted from the transmitting device. That is, when receiving a communication frame (step S41), the device 20 checks whether the serial number of the received communication frame (hereinafter referred to as a reception frame) is correct (step S42), and the serial number of the reception frame is correct (step S42). That is, if it is determined that the received frame is the first received frame (Yes in step S42), the received data is edited (step S43), and a reception confirmation notification is transmitted to the transmission source device 20 (step S45). ).

  On the other hand, if it is determined in the serial number check that the serial number is not correct (that is, duplicate communication frames have been received) (No in step S42), the apparatus 20 discards the received frame ( In step S44, a reception confirmation notification is transmitted to the transmission source (step S45). Even if a communication frame is received in duplicate, the reception confirmation notification is transmitted to the transmission source after the communication frame has been successfully received and a communication path error occurs. This is a case where the confirmation notification cannot be received and the same communication frame is retransmitted.

  FIG. 15 is a diagram illustrating an example of a processing flow of communication path detour information generation processing in the detour information management apparatus 30. The communication path detour information generation process (process of the communication path detour information generation unit 301) illustrated in FIG. 15 is performed by the detour information management apparatus 30 based on the communication path communication confirmation table 211 collected from each apparatus 20. This is a process for generating the route detour information table 212. Therefore, this communication path detour information generation processing is repeatedly executed for the number of devices 20 included in the plant monitoring / control system 10 and for each device 20 as many as the number of communication paths to which the devices 20 are connected. .

  The detour information management device 30 first designates the device 20 and communication path to be processed (step S51), and the communication path for the designated device 20 and communication path (hereinafter referred to as the device 20 and the communication path). The communication confirmation table 211 is referred to (step S52), and it is determined whether or not there is a communication disabled device (step S53). If there is no communication-impossible device as a result of the determination (No in step S53), the communication path detour information table 212 does not need to be generated, and the process is terminated as it is.

  On the other hand, when there is a non-communication device in the communication channel communication confirmation table 211 for the designated device 20 and the communication channel (No in step S53), the detour information management device 30 further determines that the device 20 has the communication. It is determined whether or not there is a communication relationship with the disabled device (step S54). As a result of the determination, if there is no communication relationship (No in step S54), there is no need to obtain detour information, and the processing is terminated as it is. If there is a communication relationship (Yes in step S54), the processing from step S55 is executed. It should be noted that the presence / absence of a communication relationship between the devices 20 may be prepared in advance as a table.

  Next, the detour information management device 30 determines whether or not there is a routing device 40 that can communicate with the device 20 in the communication path (step S55), and when there is no routing device 40 that can communicate ( No in step S55), since detour information cannot be obtained, the process is terminated as it is. If there is a routing device 40 capable of communication (Yes in step S55), the routing device 40 capable of communication is designated as device A (step S56).

  Next, the detour information management device 30 refers to the communication path communication confirmation table 211 of the communication path of the apparatus 20 that cannot communicate with the apparatus 20 (step S57), and the routing apparatus that can communicate with the communication impossible apparatus on the communication path. It is determined whether there is 40 (step S58). If there is no communication routing device 40 (No in step S58), the detour information cannot be obtained, and the process is terminated. If there is a routing device 40 capable of communication (Yes in step S58), the routing device 40 capable of communication is designated as device B (step S59).

  Next, the detour information management device 30 determines whether or not there is a communication path with which the devices A and B can communicate (step S60). No), since the detour information cannot be obtained, the process is terminated as it is. If there is a communication path that can be communicated (Yes in step S60), the apparatus A is registered in the communication path detour information table 212 for the apparatus 20 and the communication path as detour information for the non-communication apparatus. (Step S61), and the process ends.

  When the bypass information management apparatus 30 finishes the communication path bypass information generation process for all the communication paths of all the apparatuses 20, the bypass information management apparatus 30 notifies each apparatus 20 that the communication path bypass information table 212 has been updated by the process.

  The detour information management device 30 also generates a routing table 215 for the routing device 40 (see FIG. 11), but since the generation is easy, the illustration of the processing flow is omitted.

  FIG. 16 is a diagram illustrating an example of a processing flow of communication path detour information update processing in the apparatus 20. The communication path detour information update process (process of the communication path detour information update unit 203) is started by receiving an update notification of the communication path detour information table 212 from the detour information management device 30. That is, when receiving an update notification of the communication path detour information table 212 (step S71), the device 20 receives the updated communication path detour information table 212 (step S72), and receives the received communication path detour information table. Based on 212, the communication path detour information table 212 of the own apparatus is updated (step S73).

  FIG. 17 is a diagram illustrating an example of a processing flow of frame bypass transmission processing in the routing device 40. As illustrated in FIG. 17, the frame bypass transmission process (the process of the frame bypass transmission processing unit 204) is realized by the cooperation of the two routing devices 40. However, in FIG. 17, the second routing device 40 that bypasses the communication frame is described as a relay device. This indicates the same thing as the relay device in the routing table shown in FIG.

  In FIG. 17, when receiving the communication frame (step S81), the routing device 40 determines whether or not the destination of the received frame is the own device (step S82), and the destination of the received frame is the own device. In such a case (Yes in step S82), normal reception processing is performed (step S83). Here, the normal reception process is a process of the reception apparatus of the data transmission / reception process shown in FIG. 14 (steps S41 to S45).

  If the destination of the received frame is not the own apparatus (No in step S82), the routing device 40 bypasses the communication path for the communication path of the own apparatus (the communication path used for transmission / reception of the received frame). The information table 212 is referred to (step S84), and it is determined whether or not the detour information for the destination is the own device (step S85).

  As a result of the determination, if the detour information for the destination is not the own device (No in step S85), the routing device 40 does not need to perform detour processing, and thus ends the processing as it is. If the detour information for the destination is the own device (Yes in step S85), the routing device 40 refers to the routing table 215 of the own device (step S86), and performs another routing that can communicate with the destination device. The device 40 (different from its own device) is selected as a relay device (step S87).

  At this time, the routing device 40 and the other routing device 40 designated as the relay device are connected by the communication path 11 (see FIGS. 1 and 5) outside the plant monitoring / control system 10 and can communicate with each other. Suppose there is. Therefore, the routing device 40 transmits the communication frame received in step S81 to the relay device via the other communication path 11 (step S88).

  The relay apparatus receives the communication frame transmitted via the external communication path 11 (step S91), and sends the received communication frame to the communication path where the own apparatus and the destination apparatus can communicate ( Step S92).

  Through the above processing, a communication frame received by the routing device 40 and not destined for the routing device 40 is diverted from the routing device 40 to the external communication path 11 and passes through a relay device that is another routing device 40. The communication frame is transmitted to the destination device 20.

  In the frame bypass transmission process shown in FIG. 17, the routing device 40 refers to its own communication path bypass information table 212 in step S <b> 84, but refers to the communication path communication confirmation table 211 or the routing table 215. You may do it. In that case, instead of the determination in step S85, whether or not communication between the own apparatus and the destination apparatus of the communication frame is determined based on the referenced communication path communication confirmation table 211 or the routing table 215, and communication is impossible. If so, the process proceeds to the next step S86.

  In this case, the communication frame may be diverted to the external communication path 11 by the plurality of routing devices 40 and transmitted to the destination device. Therefore, the destination device may receive the same communication frame multiple times, but the destination device determines the serial number at the time of reception and discards the duplicate communication frame (see steps S42 and S44 in FIG. 14). Absent.

  As described above, according to the present embodiment, when the redundant redundant communication path 11 is added to the plant monitoring / control system 10 having the redundant communication paths 13 and 14 as shown in FIG. When a failure occurs in the unique communication paths 13 and 14, a detour path that can bypass the failure can be formed via the communication path 11. Therefore, the reliability of communication in the plant monitoring / control system 10 is improved.

  That is, according to the present embodiment, in a plant monitoring / control system having multiplexed communication paths, it is possible to easily improve communication reliability by using an existing communication path provided outside the plant monitoring / control system. Is possible.

  In the present embodiment, the survival notification frame is always transmitted and received between the devices, and the communication path detour information table 212 of each device 20 and the routing table of the routing device 40 are generated. Therefore, a detour route when a failure occurs in the system-specific communication channels 13 and 14 is always prepared. That is, as in the prior art (see Patent Documents 1 to 3, etc.), communication is not performed when the communication is performed at the time of communication, and as a result, communication via an alternative route by detour is possible. (Conversely, there is no alternative route) Therefore, the present invention can be applied to a high-reliability system that cannot tolerate the disappearance of an alternative path, or a high-reliability system that always repairs a faulty part and maintains a redundant system while there is an alternative path. Become.

  Next, a modification of the present embodiment will be described with reference to FIGS. Here, FIG. 18 is a diagram showing an example of the configuration of the plant monitoring / control system according to the first modification of the embodiment of the present invention, and FIG. 19 is a second modification of the embodiment of the present invention. It is the figure which showed the example of the structure of the plant monitoring and control system which concerns.

  In the plant monitoring / control system 10 shown in FIG. 1, the communication paths 11 to 15 are configured by a one-segment communication path in the bus format, but in the plant monitoring / control system 10 a shown in FIG. The segment communication paths 11 to 15 include switches or hubs 11a to 15a. In this case, the entire communication path looks like a mesh-structured communication network, but in this embodiment, the transmission / reception of the survival notification frame is limited to devices within one frame. This modification can be applied without any problem.

  Further, as shown in FIG. 19, the spare redundant path outside the plant monitoring / control system 10b is not a one-frame communication path, but may be a large-scale LAN (Local Area Network), the Internet 50, or the like. . In this case, since transmission / reception of the survival notification frame for monitoring the external communication path is limited to devices included in the plant monitoring / control system 10b, no particular problem occurs. In this case, however, the survival notification frame cannot be transmitted by broadcast, and the destination must be specified by multicast or the like.

  In FIG. 19, the internal communication path of the plant monitoring / control system 10b is configured to include the hubs 12b to 15b, but the bus-type communication paths 11 to 15 as shown in FIG. May be.

  Furthermore, when supplementing the embodiment described above and its modification, the communication frame and the transmission / reception protocol of each communication path may be different. In that case, it is assumed that each device appropriately converts communication frames and protocols between the respective communication paths.

The figure which showed the example of the structure of the plant monitoring and control system which concerns on embodiment of this invention. The figure which showed the example of the structure of the communication path priority table with respect to each apparatus contained in the plant monitoring and control system which concerns on embodiment of this invention. The figure which showed the example of the routing apparatus definition table with respect to each communication path contained in the plant monitoring and control system which concerns on embodiment of this invention. The figure which showed the example of the communication channel communication confirmation table of the apparatuses 24 and 28 when there is no failure in a communication channel. The figure which showed the example of the position of the failure which arose in the communication path inside a plant monitoring and control system. The figure which showed the example of the communication path communication confirmation table of the apparatuses 24 and 28 when a failure arises in the location of the communication path shown in FIG. The figure which showed the example of the communication path detour information table of the apparatuses 24 and 28. FIG. The figure which showed the example of the communication path communication confirmation table of the apparatuses 21 and 23. FIG. The figure which showed the example of the communication path detour information table of the apparatuses 21 and 23. FIG. The figure which showed the example of a structure of the communication process part in a normal apparatus, and the detour information concentration process part in a detour information management apparatus. The figure which showed the example of a structure of the communication process part in a routing apparatus, and the detour information concentration process part in a detour information management apparatus. The figure which showed the example of the structure of the routing table of the apparatus 24. FIG. The figure which showed the example of the processing flow of the communication path monitoring process in a normal apparatus. The figure which showed the example of the processing flow of the data transmission / reception process in the normal apparatus. The figure which showed the example of the processing flow of the communication path detour information generation process in the detour information management apparatus. The figure which showed the example of the processing flow of the communication path detour information update process in a normal apparatus. The figure which showed the example of the processing flow of the frame detour transmission process in a routing apparatus. The figure which showed the example of the structure of the plant monitoring and control system which concerns on the 1st modification of embodiment of this invention. The figure which showed the example of the structure of the plant monitoring and control system which concerns on the 2nd modification of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Plant monitoring / control system 11, 12, 13, 14, 15 Communication path 20 Normal apparatus 21, 22, 23 Plant monitoring / control apparatus 24, 25 Operation monitoring HMI apparatus 26 Design / office personal computer 27 Storage apparatus 28, 29 System Management server device 30 Detour information management device 31 Design / office server device 40 Routing device 50 Internet 200 Communication processing unit 201 Communication path monitoring processing unit 202 Data transmission / reception processing unit 203 Communication path detour information update unit 204 Frame detour transmission processing unit 211 Communication Route communication confirmation table 212 Communication path detour information table 213 Communication path priority table 214 Routing device definition table 215 Routing table 300 Detour information concentration processing section 301 Communication path detour information generation section 400 Communication processing section

Claims (12)

A plant monitoring / control system configured to include a plurality of devices that monitor or control the operation of the plant, and a first communication network that interconnects the plurality of devices,
At least two of the plurality of devices are
Connected to a second communication network different from the first communication network;
When communication between devices connected to the first communication network becomes impossible, a part of the communication path in the first communication network that connects the devices that cannot communicate with each other is connected to the first communication network. Function as a routing device that bypasses the communication network
The device functioning as the routing device is:
As a result of confirming whether communication is possible or not by transmitting / receiving a survival notification frame between the own device and another device connected to the first communication network via the first communication network at predetermined time intervals. Create a communication channel confirmation table based on
When the destination of the communication frame received via the first communication network is not the own device but another device connected to the first communication network, the communication path communication for the own device is performed. Referring to the confirmation table, it is determined whether or not the own device and the destination device can communicate with each other via the first communication network,
As a result of the determination, if it is determined that communication is impossible, the received communication frame is bypassed via the second communication network to another routing device connected to the second communication network. Send
The other routing device that has received the bypassed communication frame,
The plant monitoring / control system, wherein the received communication frame is transmitted to the destination device via the first communication network. The routing device
A routing table configured to include destination information of another routing device different from the own device, and the communication path communication confirmation table for each of the other routing devices,
When detouring the communication frame received via the first communication network via the second communication network,
With reference to the communication path communication confirmation table for the other routing device, a routing device capable of communicating between the other routing device and a destination device in the first communication network of the communication frame is selected. ,
The plant monitoring / control system according to claim 1, wherein the communication frame is detoured and transmitted to the selected routing device via the second communication network. Among the devices connected to the first communication network, one specific device is a detour information management device,
The detour information management device includes:
From each of the routing devices, obtain the communication path communication confirmation table created by the respective routing device,
Based on the acquired communication path communication confirmation table, generate the routing table for each of the routing devices,
The plant monitoring / control system according to claim 2, wherein the generated routing table is transmitted to each of the routing devices. The detour information management device includes:
From each device connected to the first communication network, obtain the communication path communication confirmation table created by the respective device,
When there is a communication destination device that cannot communicate in the acquired communication path communication confirmation table, destination information of the routing device that is routed to bypass communication with the communication destination via the communication network of 2 A communication path detour information table configured to include,
The plant monitoring / control system according to claim 3, wherein the generated communication path detour information table is transmitted to each of the devices. The plant monitoring / control system according to claim 1, wherein the first communication network includes a single-segment communication path. The first communication network is composed of a plurality of communication channels of a single segment,
The plant monitoring / control system according to claim 1, wherein at least some of the devices connected to the first communication network are connected in parallel to each of the plurality of communication paths. At least two of the plurality of devices in the plant monitoring / control system configured to include a plurality of devices that monitor or control the operation of the plant and a first communication network that interconnects the plurality of devices. In a configuration in which two devices are further connected to a second communication network different from the first communication network, the at least two devices connected to the second communication network function as routing devices,
When communication between devices connected to the first communication network becomes impossible, a part of a communication path in the first communication network that connects devices that are disabled to communicate with each other, A method of detouring a communication path for detouring to the second communication network via a routing device,
The routing device
As a result of confirming whether communication is possible or not by transmitting / receiving a survival notification frame between the own device and another device connected to the first communication network via the first communication network at predetermined time intervals. Create a communication channel confirmation table based on
If the destination of the communication frame received via the first communication network is not the own device but another device connected to the first communication network, the communication path communication for the own device is performed. Referring to the confirmation table, it is determined whether or not the own device and the destination device can communicate with each other via the first communication network,
As a result of the determination, if it is determined that communication is impossible, the received communication frame is bypassed via the second communication network to another routing device connected to the second communication network. Send
The other routing device that has received the bypassed communication frame,
A communication path detouring method comprising: transmitting the received communication frame to the destination device via the first communication network. The routing device
A routing table configured to include destination information of another routing device different from the own device, and the communication path communication confirmation table for each of the other routing devices,
When detouring the communication frame received via the first communication network via the second communication network,
With reference to the communication path communication confirmation table for the other routing device, a routing device capable of communicating between the other routing device and a destination device in the first communication network of the communication frame is selected. ,
The communication path detouring method according to claim 7, wherein the communication frame is detoured and transmitted to the selected routing device via the second communication network. Among the devices connected to the first communication network, one specific device is a detour information management device,
The detour information management device includes:
From each of the routing devices, obtain the communication path communication confirmation table created by the respective routing device,
Based on the acquired communication path communication confirmation table, generate the routing table for each of the routing devices,
The communication path detouring method according to claim 8, wherein the generated routing table is transmitted to each of the routing devices. The detour information management device includes:
From each device connected to the first communication network, obtain the communication path communication confirmation table created by the respective device,
When there is a communication destination device that cannot communicate in the acquired communication path communication confirmation table, destination information of the routing device that is routed to bypass communication with the communication destination via the communication network of 2 A communication path detour information table configured to include,
The communication path detouring method according to claim 9, wherein the generated communication path detour information table is transmitted to each of the devices. The communication path detouring method according to claim 7, wherein the first communication network includes a single-segment communication path. The first communication network is composed of a plurality of communication channels of a single segment,
The communication path detouring method according to claim 7, wherein at least some of the devices connected to the first communication network are connected in parallel to each of the plurality of communication paths.

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