JP2014003364A - Communication device and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication device and a communication method that can continue transmission processing of instruction information in a state in which a master control device cannot execute a master program to perform transmission processing of the instruction information instructing control processing of a control object device.SOLUTION: A communication device according to an embodiment is any one of a plurality of communication devices which perform control processing according to instruction information and are connected via a communication network to a master control device which includes a first execution unit for executing a first program to perform transmission processing of the instruction information instructing control processing of a control object device and a second execution unit for executing a second program to accelerate transmission processing by alternatively executing part of processing of transmission processing by the first program. The communication device comprises an execution unit. The execution unit executes the first program substituting for the first execution unit in a state in which the first execution unit cannot execute the first program.

Description

  Embodiments described herein relate generally to a communication device and a communication method.

  Since the technology of a control system in which a control device as a master station and an I / O device as a slave station are connected via a network has been developed, network devices included in the control system have been developed. I / O devices installed on the ground can now be operated as a single control system.

  A general control system transmits an instruction signal instructing control of a field device (control target device) connected to an I / O device from the control device to the I / O device by an operator's operation. To control. For example, when controlling a water-injection valve (field device) that reduces the temperature of a pipe in a power plant, if the temperature sensor detects that the pipe temperature is high and sends the detection result to the control device, The device transmits an instruction signal instructing the I / O device to open the water injection valve, and controls the temperature of the pipe by causing the water injection valve to open.

  In addition, in order to improve the reliability and safety of the control system, by providing a plurality of control devices in the control system, when an abnormality occurs in one control device in the control system, other control devices The abnormality of the one control device is detected, information is acquired from the one control device, and functions as a master station. Thereby, even when an abnormality occurs in one control device, the control of the entire control system can be continued.

JP 2004-341645 A

  By the way, in order to ensure the safe operation of the control system, it is necessary for the user to periodically inspect each device included in the control system. However, a single control device and a plurality of I / Os are required. In a control system including a device, when the control device is arbitrarily stopped for inspection of the control system, the field device cannot be controlled and the operation as the control system cannot be continued. There is. In addition, a control system including a single control device and a plurality of I / O devices should continue to operate as a control system even when the control device fails accidentally or the network is disconnected. There is a problem that cannot be done.

  The communication apparatus according to the embodiment substitutes a first execution unit for executing a first program for executing a transmission process of instruction information for instructing a control process for a control target device and a part of the transmission process by the first program. A plurality of communication devices that are connected to a main control device having a second execution unit that executes a second program for speeding up transmission processing through a communication network and execute control processing according to instruction information Any one of the communication devices includes an execution unit. The execution unit executes the first program instead of the first execution unit when the execution of the first program by the first execution unit becomes an inexecutable state.

FIG. 1 is a block diagram illustrating a configuration of a control system according to the present embodiment. FIG. 2 is a diagram illustrating a memory configuration of the master control device and the remote I / O station included in the control system according to the present embodiment. FIG. 3 is a flowchart showing a flow of processing executed in the master control device provided in the control system according to the present embodiment. FIG. 4 is a flowchart showing a flow of processing executed in the remote I / O station included in the control system according to the present embodiment.

  FIG. 1 is a block diagram illustrating a configuration of a control system according to the present embodiment. FIG. 2 is a diagram illustrating a memory configuration of the master control device and the remote I / O station included in the control system according to the present embodiment. The control system 1 according to the present embodiment includes a single master control device 10 (main control device), a plurality of remote I / O stations 11 (communication devices), an IO module 12, and a field device 13 (control target device). ) And.

  The field device 13 is a device to be controlled that is controlled by the master control device 10 in the control system 1. The IO module 12 connects the field device 13 and the remote I / O station 11.

  In the present embodiment, the master control device 10 includes an MPU (Micro Processing Unit) 101, a memory 102, an LPU (Language Processing Unit) 103, and a network I / F 104. As shown in FIG. 2, the memory 102 detects instruction information for instructing control processing of the field device 13 (for example, when the field device 13 is a water-cooling water injection valve that lowers the temperature of the pipe of the power plant, detected by a temperature sensor). A first storage area 201 for storing a user program including a signal for instructing opening / closing of a water injection valve in accordance with the temperature of the pipe, and the master control device 10 by executing a transmission process of instruction information included in the user program A second storage area 202 for storing a first control program for ensuring the minimum operation of the second control program, and a second control program for accelerating the transmission process by substituting a part of the transmission process by the first control program The third storage area 203 is provided.

  The network I / F 104 connects the master control device 10 to a communication network. The MPU 101 executes the first control program stored in the second storage area 202 and transmits instruction information for instructing control processing of the field device 13 to the field device 13 via the network I / F 104. In the present embodiment, the MPU 101 functions as a first execution unit that executes the first control program. In this embodiment, the master control device 10 uses the MPU 101 as a control element that executes the first control program. However, the master control apparatus 10 is a control element that can execute the first control program faster than the remote I / O station 11. I need it.

  When the first control program is executed by the MPU 101, the LPU 103 executes the second control program stored in the third storage area 203 and substitutes a part of the transmission processing by the first control program. As a result, the LPU 103 increases the speed of control processing executed by the MPU 101. In the present embodiment, the LPU 103 functions as a second execution unit that executes the second control program.

  The remote I / O station 11 is connected to the master control device 10 via a communication network, and executes control processing for the field device 13 in accordance with the instruction information transmitted from the master control device 10. The remote I / O station 11 executes the first control program instead of the MPU 101 of the master control device 10 when the master control device 10 becomes unable to execute the first control program.

  In the present embodiment, the remote I / O station 11 includes an FPGA (Field Programmable Gate Array) 111, a memory 112, and a network I / F 113. As shown in FIG. 2, the memory 112 has a first storage area 204 for storing a user program and a second storage area 205 for storing a first control program.

  The network I / F 113 connects the remote I / O station 11 to the network. The FPGA 111 executes the first control program stored in the second storage area 205 instead of the MPU 101 when the execution of the first control program by the MPU 101 included in the master control device 10 becomes inexecutable. As a result, although the processing speed is lower than when the MPU 101 included in the master control device 10 performs the instruction information transmission process, even if the execution of the first control program by the MPU 101 is disabled, the field device 13 It is possible to continue the transmission process of the instruction information for. In the present embodiment, the FPGA 111 functions as an execution unit that executes the first control program.

  Next, processing executed in the master control device 10 included in the control system 1 according to the present embodiment will be described in detail with reference to FIG. FIG. 3 is a flowchart showing a flow of processing executed in the master control device provided in the control system according to the present embodiment.

  The master control device 10 executes the first control program by the MPU 101 when an abnormality occurs in the master control device 10 or when the master control device 10 is inspected at the initial operation stage when the master control device 10 is activated. When the execution is disabled, the remote I / O station 11 for executing the first control program is selected instead of the MPU 101.

  Specifically, the MPU 101 acquires selection information for a plurality of remote I / O stations 11 connected to the master control device 10 via the network I / F 104 when the master control device 10 is in the initial operation stage. The acquisition signal for transmitting is transmitted to the remote I / O station 11 (step S301). Here, the selection information is information used to select the remote I / O station 11 that executes the first control program on behalf of the MPU 101 when the execution of the first control program by the MPU 101 becomes impossible. . For example, the selection information includes the communication time required for communication between the master control device 10 and the remote I / O station 11, the number of field devices 13 that the remote I / O station 11 executes control processing, and the remote I / O For example, the FPGA 111 provided in the station 11 has a processing capability that can be applied to the execution of the first control program. In the present embodiment, the MPU 101 transmits acquisition signals to a plurality of remote I / O stations 11 using a PING (Packet Internet Groper) function.

  Next, the MPU 101 receives a response signal to the acquisition signal from the remote I / O station 11 via the network I / F 104 (step S302). In the present embodiment, the MPU 101 responds including the number of field devices 13 that the remote I / O station 11 executes control processing and the processing capability that the FPGA 111 provided in the remote I / O station 11 can execute to execute the first control program. Receive a signal.

  When receiving the response signal from the remote I / O station 11, the MPU 101 acquires selection information based on the received response signal and selects the remote I / O station 11 based on the acquired selection information (step S303). . Then, the MPU 101 notifies the selected remote I / O station 11 that it has been selected. In the present embodiment, when the MPU 101 receives a response signal from the remote I / O station 11, the MPU 101 cannot execute the first control program using any of the first to third selection methods described below. In this case, the remote I / O station 11 that executes the first control program instead of the MPU 101 is selected in advance. In the present embodiment, the remote I / O station 11 that executes the first control program is selected in advance when the execution of the first control program by the MPU 101 becomes inexecutable. For example, when the remote I / O station 11 (FPGA 111) determines whether or not the selection condition set in advance is satisfied and determines that the selection condition is satisfied, the first A control program may be executed.

  First, a method for selecting the remote I / O station 11 by the first selection method will be described. When the remote I / O station 11 is selected by the first selection method, the MPU 101 acquires a communication time required for communication between the own apparatus and the remote I / O station 11 based on the received response signal. Specifically, the MPU 101 acquires the time from when the acquisition signal is transmitted by the PING function until the response signal is received as the communication time. Then, the MPU 101 selects the remote I / O station 11 having the shortest acquired communication time from among the plurality of remote I / O stations 11. When the control system 1 is operating normally, the master control device 10 and the remote I / O station 11 may transmit and receive information several times per second. Therefore, the MPU 101 acquires the time required for information transmission / reception between the master control device 10 and the remote I / O station 11 as a communication time, and the remote I / O station 11 with the shortest acquired communication time is When the execution of the first control program by the MPU 101 becomes inexecutable, the remote I / O station 11 to be executed as the first control program is selected instead of the MPU 101. As a result, when the execution of the first control program by the MPU 101 is in an inexecutable state, the remote I / O station 11 capable of detecting the earliest that the execution of the first control program by the MPU 101 has become inexecutable Since the selection can be made, it is possible to shorten the time during which the device functioning as the master control device 10 is absent in the control system 1. In the present embodiment, it is determined whether or not the execution of the first control program by the MPU 101 has become unexecutable depending on whether or not there is a response to various signals transmitted to the master control device 10.

  Next, a method for selecting the remote I / O station 11 by the second selection method will be described. When selecting the remote I / O station 11 by the second selection method, the MPU 101 includes the number of field devices 13 that the remote I / O station 11 executes control processing included in the received response signal (via the IO module 12). The number of field devices 13 connected to each remote I / O station 11) is acquired as selection information. Then, the MPU 101 selects the remote I / O station 11 having the smallest number of field devices 13 acquired as selection information. According to the second selection method, the remote I / O station 11 having the smallest number of field devices 13 connected through the IO module 12 and the smallest processing load due to the execution of the control processing can be selected. When the execution of the first control program becomes inexecutable, it is possible to prevent an increase in processing load on a specific remote I / O station 11 among the plurality of remote I / O stations 11.

  Next, a method for selecting the remote I / O station 11 by the third selection method will be described. When the remote I / O station 11 is selected by the third selection method, the MPU 101 selects the processing capability included in the received response signal so that the FPGA 111 provided in the remote I / O station 11 can be used to execute the first control program. Get as. Then, the MPU 101 selects the remote I / O station 11 having the highest processing capability acquired as selection information (for example, the remote I / O station 11 having a small amount of information exchanged with the field device 13). According to the third selection method, it is possible to select the remote I / O station 11 having a small amount of information exchanged with the field device 13 and having a high processing capacity for executing the first control program. When the execution of the first control program becomes impossible, the remote I / O station 11 that can execute the first control program at a high speed can be selected from the plurality of remote I / O stations 11.

  The MPU 101 determines which of the first to third selection methods is used to select the remote I / O station 11 based on information included in the received response signal. For example, when the received response signal does not include either the number of field devices 13 or the processing capacity that the FPGA 111 is subjected to the execution of the first control program, the MPU 101 uses the first selection method to perform remote I / O. Station 11 is selected. When the received response signal includes the number of field devices 13, the MPU 101 selects the remote I / O station 11 using the second selection method. Further, when the received response signal includes the processing capability that the FPGA 111 can execute to execute the first control program, the MPU 101 selects the remote I / O station 11 using the third selection method. Furthermore, when the received response signal includes both the number of the field devices 13 and the processing capability, the MPU 101 uses a selection method set in advance among the second selection method and the third selection method. The remote I / O station 11 is selected. Further, when the priority order is set in advance in the first to third selection methods, the MPU 101 may select the remote I / O station 11 using a selection method having a higher priority order.

  When the remote I / O station 11 is selected, the MPU 101 executes the first control program stored in the second storage area 202 and is included in the user program stored in the first storage area 201 of the memory 102. Instruction information is transmitted (step S304). When the first control program is executed by the MPU 101, the LPU 103 executes the second control program stored in the third storage area 203 of the memory 102 and substitutes a part of the transmission processing by the first control program. To do.

  Further, the MPU 101 stores memory for the remote I / O station 11 selected in step S303 while the master control device 10 is operating normally (that is, while the first control program is being executed). The user program stored in the first storage area 201 of 102 is divided and transmitted (step S305). In this embodiment, the MPU 101 transmits a user program to the selected remote I / O station 11, but transmits a user program to a plurality of I / O stations 11 included in the control system 1. You can leave it.

  Next, processing executed in the remote I / O station 11 selected in advance as the remote I / O station 11 that executes the first control program on behalf of the master control device 10 will be described in detail with reference to FIG. . FIG. 4 is a flowchart showing a flow of processing executed in the remote I / O station included in the control system according to the present embodiment.

  When notified by the master control device 10 that the FPGA 111 of the remote I / O station 11 has been selected, the user program transmitted from the master control device 10 is stored in the first storage area 204 of the memory 112 and the master It is detected whether or not the execution of the first control program in the control device 10 has become impossible (step S401). In the present embodiment, when notified of selection, the FPGA 111 executes the first control program by the master control device 10 depending on whether there is a response to various signals transmitted to the master control device 10. It detects whether it is in an impossible state. If there is no response to the various signals transmitted to the master control device 10, the FPGA 111 detects that an abnormality has occurred in the master control device 10 or the master control device 10 stops due to inspection and executes the first control program. Is determined to be in an inexecutable state.

  When it is detected that the execution of the first control program by the master control device 10 has become impossible (step S401: Yes), the FPGA 111 transmits another remote I / O station 11 (via the network I / F 113). An acquisition signal for acquiring selection information is transmitted to the remote I / O station 11 to another communication device (step S402). Here, the selection information is information used for selecting the remote I / O station 11 that executes the first control program in place of the MPU 101. For example, the selection information includes the communication time required for communication with another remote I / O station 11, the number of field devices 13 that the other remote I / O station 11 executes control processing, and other remote I / O stations. For example, the FPGA 111 included in the O station 11 has a processing capability that can be applied to the execution of the first control program. In the present embodiment, the FPGA 111 transmits an acquisition signal to another remote I / O station 11 using the PING function.

  Next, the FPGA 111 receives a response signal to the acquisition signal from the other remote I / O station 11 via the network I / F 113 (step S403). In the present embodiment, the FPGA 111 is a process in which the number of field devices 13 that the other remote I / O station 11 executes control processing and the FPGA 111 provided in the other remote I / O station 11 is subjected to the execution of the first control program. A response signal including the capability is received.

  When receiving the response signal from the other remote I / O station 11, the FPGA 111 acquires selection information based on the received response signal and selects the remote I / O station 11 based on the acquired selection information (step). S404). Then, the FPGA 111 notifies the selected remote I / O station 11 that it has been selected. In this embodiment, when the FPGA 111 receives a response signal from the remote I / O station 11, it uses another of the first to third selection methods described above, and then executes another remote control that executes the first control program instead of the MPU 101. I / O station 11 is selected. The details of the first to third selection methods are the same as those of the first to third selection methods in the master control device 10 described above.

  When the remote I / O station 11 is selected, the first control program stored in the second storage area 205 is executed, and the instruction information included in the user program stored in the first storage area 204 is transmitted ( Step S405).

  Further, while the FPGA 111 is operating normally (that is, while the first control program is being executed), the FPGA 111 stores the second I / O station 11 selected in step S404. The user program stored in one storage area 204 is divided and transmitted (step S406).

  As described above, according to the remote I / O station 11 of the present embodiment, when the execution of the first control program by the MPU 101 of the master control device 10 becomes inexecutable, the first control program is executed instead of the MPU 101. As a result, even if the execution of the first control program by the MPU 101 of the master control device 10 is in an inexecutable state, the instruction information transmission process for instructing the control processing of the field device 13 can be continued. Even when the execution of the first control program by the MPU 101 of the control device 10 becomes inexecutable, the operation of the control system 1 can be continued. Moreover, since it is not necessary to provide in the control system 1 the some master control apparatus 10 which executes a master program (a user program, a 1st control program, and a 2nd control program), the cost on equipment can be reduced. . Furthermore, it is possible to prevent an increase in the number of work steps due to the introduction of the master program, and it is possible to simplify the work of detecting a location where an abnormality has occurred.

  The program executed in the master control device 10 and the remote I / O station 11 of the present embodiment is a file in an installable format or an executable format, and is a CD-ROM, flexible disk (FD), CD-R, DVD ( And recorded on a computer-readable recording medium such as a digital versatile disk.

  The program executed by the master control device 10 and the remote I / O station 11 according to the present embodiment is stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. You may do it. Further, the program executed by the master control device 10 and the remote I / O station 11 of the present embodiment may be provided or distributed via a network such as the Internet.

  Further, the program executed in the master control device 10 and the remote I / O station 11 according to the present embodiment may be provided by being incorporated in advance in a ROM (Read Only Memory) or the like.

  Although the embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 Master Control Device 11 Remote I / O Station 12 IO Module 13 Field Device 101 MPU
102,112 Memory 103 LPU
104,113 Network I / F
111 FPGA
201, 204 First storage area 202, 205 Second storage area 203 Third storage area

Claims (7)

The first execution unit that executes a first program for executing a transmission process of instruction information for instructing a control process for a control target device, and the transmission process instead of a part of the transmission process by the first program Any one of a plurality of communication devices connected to a main control device having a second execution unit for executing a second program for speeding up the communication via a communication network and executing the control process according to the instruction information Communication device,
An execution unit that executes the first program instead of the first execution unit when the execution of the first program by the first execution unit becomes an inexecutable state;
A communication device comprising:   The communication device according to claim 1, wherein the execution unit executes the first program when the own device is selected in advance from the plurality of communication devices or when a predetermined selection condition is satisfied. . Next, a transmission unit that transmits to the communication device an acquisition signal for acquiring selection information used to select another communication device that executes the first program instead of the first execution unit;
A receiving unit that receives a response signal to the acquired signal transmitted from the other communication device;
A selection unit that acquires the selection information based on the response signal and selects the other communication device based on the acquired selection information;
The communication apparatus according to claim 2, further comprising:   The selection unit acquires, as the selection information, a communication time required for communication between the own device and the other communication device based on the response signal, and selects the other communication device with the shortest communication time. The communication device according to claim 3 to be selected. The receiving unit receives the response signal including the number of devices to be controlled on which the other communication device executes the control process,
The communication device according to claim 3, wherein the selection unit acquires the number of the control target devices as the selection information and selects the other communication device having the smallest number of the acquired control target devices. The receiving unit receives the response signal including a processing capability of the execution unit included in the other communication device to be executed to execute the first program;
The communication device according to claim 3, wherein the selection unit acquires the processing capability as the selection information and selects the other communication device having the highest acquired processing capability. The first execution unit that executes a first program for executing a transmission process of instruction information for instructing a control process for a control target device, and the transmission process instead of a part of the transmission process by the first program Any one of a plurality of communication devices connected to a main control device having a second execution unit for executing a second program for speeding up the communication via a communication network and executing the control process according to the instruction information A communication method executed by a communication device of
The communication device
A step of executing the first program in place of the first execution unit when the execution unit is unable to execute the first program by the first execution unit;
Including a communication method.

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