TWI674488B - Control system, and relay device - Google Patents

Abstract

In the control system where the control device and the data transmission path have been dualized, even if the amount of data transmitted by the control device increases, it will not cause obstacles to the execution of the original calculation of the control device, and will not cause the operation system / standby. The system switching speed is reduced, and the monitoring data can be equivalent. Each control device of the operation system and the standby system is connected with a first equivalent cable, and each network device of the operation system and the standby system is connected with each other by a second equivalent cable. Each network device is instructed to transmit the monitoring data received from the IO slave device to the control device of the connection target, and at the same time, determine whether communication via the second equalization cable is possible. If the communication is possible, the network devices are equivalently monitored by the communication through the second equivalent cable. If not, the network devices are equivalently transmitted through the second equivalent. The communication of cables is used to equalize monitoring data.

Description

Control system and relay device

The present invention relates to a control system including a control device of an operation system and a standby system, and a relay device thereof.

In industrial facilities such as factories or various workshops, a communication system called a control system is often constructed in order to control various operations. The control system includes a control device that collects monitoring data from a sensor installed in an industrial facility or performs drive control of a motor or the like according to the result of the collection. As such a control device, a DCS (Distributed Control System) or a programmable logic controller is used. Hereinafter, a control target device of a control device such as a motor is referred to as a “control target device”, and a device that is a target of collection of monitoring data of the control device as the sensor described above and a control target device are referred to as “IO auxiliary devices Device. " The IO slave device is connected to a network called an IO network or a serial bus. The control device is connected to the IO network through a network device such as a relay device. An example of this relay device is a gateway device. In the following, the programmable logic controller is referred to as "PLC". In a general FA (Factory Automation) system, PLC is often used as a control device, and DCS is often used as a control device in plant equipment that requires high reliability. This is because DCS is more reliable than PLC.

In such a control system, in order to avoid a failure in operation due to a failure of a control device, etc., it is common to double a control device and a data transmission path of monitoring data. The so-called dual control device is provided with two control devices so that one of them is an operation system and the other is a standby system. Each of these two control devices collects monitoring data, and uses the collected monitoring data, or uses the collected monitoring data and past calculation results to perform predetermined calculations required for machine control. The control device of the operation system performs control based on the calculation result, and the control device of the standby system stops the control device of the preventive operation system. Then, the control system of the standby system operates as the operation system when the operation system is stopped or has been stopped, and the machine control is continued. Here, specific examples of the stopping of the control system as the operation system include consideration of unexpected stoppages due to the occurrence of certain malfunctions or failures, or planned stoppages due to warranty repairs, and the like. The control system of the standby system is prepared to prevent both types of stop. The duplication of the data transmission path is, for example, a data transmission path from an IO slave device to one of the control devices that has been doubled, and a data transmission path to the other is separately provided. Hereinafter, a control system in which both the control device and the data transmission path are doubled is referred to as a "redundant control system".

FIG. 18 is a diagram showing a configuration example of a redundant control system. The system shown in FIG. 18 is a system that will detect various kinds of sensors installed in industrial facilities. The monitoring data output by the IO auxiliary machine devices S1 to Sn is collected, and based on these monitoring data, or using the monitoring data and past calculation results, a predetermined calculation is performed, and motors, etc. are performed according to the calculation results Control system for actuation control. In addition, n is a natural number of 2 or more. This control system includes two control devices of the control device 10A and the control device 10B, and two network devices of the network device 20A and the network device 20B. In the system shown in FIG. 18, one of the control device 10A and the control device 10B becomes the operation system, and the other becomes the standby system to prevent the stop of the operation system. The control device 10A and the control device 10B are connected to a monitoring system 50 necessary for monitoring the operation state and the like of the control device 10A and the control device 10B. The control device 10A is connected to the IO network 30A through the network device 20A, and the control device 10B is connected to the IO network 30B through the network device 20B. Each of the IO slave devices S1 to Sn is connected to both the IO network 30A and the IO network 30B.

In the system shown in FIG. 18, each of the control device 10A and the control device 10B is connected by an equalization cable 40 for status monitoring of the other party. As mentioned above, the control system of the standby system is used to prevent the control system of the operation system due to an unexpected stop due to a failure or a planned stop due to warranty repairs, etc., but the following is only an example of a stop due to a failure. To explain. Each of the control device 10A and the control device 10B sends the presence or absence of a failure, that is, the status data indicating the state of the own device to the other party through the equalization cable 40. For example, when the control device 10A is an operation system, the control is a standby system. The device 10B refers to the status data transmitted from the control device 10A through the equalization cable 40 to monitor the occurrence of a failure of the control device 10A. Then, the control device 10B detects the failure of the control device 10A based on the status data received through the equalization cable 40, and then becomes the operation system and starts to operate. On the other hand, the fact that the control device 10A starts the operation of the control device 10B after it has become the operation system is detected by the communication of the equalization cable 40, and then it becomes the standby system and operates.

In the redundant control system, even if the control system of the operation system fails, the operation system / standby system is switched, and data collection and follow-up from each of the IO auxiliary machine devices S1 to Sn are continued. The calculations that should be based on the results of the collection and the controls that follow the results of the calculations. However, only the switching between the operation system and the standby system is performed, and before and after the switching, there may be a problem such as a sudden change in the calculation result. This is because the monitoring data sent from each of the IO slave device devices S1 to Sn to the control device 10A and the control device 10B are not necessarily completely the same.

In order to avoid such a bad situation, in a redundant control system, each control device is generally executed, and the monitoring data sent from each IO auxiliary device S1 to Sn to each control device is equivalent. Or equalization of calculation results. The equivalent of monitoring data means that the control device of the operation system sends the monitoring data received via the network device to the control device of the standby system through the equalization cable 40, and overwrites the monitoring data with the monitoring data. Monitoring data received by the standby control device via the network. In addition, the so-called equalization of calculation results is expressed as The data of the calculation results in the operation system are transmitted to the control system of the standby system through the equalization cable 40, and the calculation results in the standby system are overwritten with the data. An example of such a redundant control system and equivalent prior art is a technique disclosed in Patent Document 1 or Patent Document 2.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-12094

[Patent Document 2] Japanese Patent Laid-Open No. 2013-152631

In recent years, with the diversification or increase of the number of IO auxiliary device devices included in the control system and the increase in the data transmission speed in the IO network, the monitoring data sent to the control device via the network device per unit time The amount of data has also increased significantly. Once the amount of monitoring data received by the control device via the network device increases, the processing load for the equalization processing of these monitoring data will increase, and the original role of the control device is the calculation required for machine control It is sometimes difficult to allocate sufficient resources for the execution of the machine or the machine control corresponding to the result of the calculation. Moreover, in recent years, the demand for connecting a plurality of network devices to one control device has been increasing, but the same problem occurs when the number of network devices connected to the control device increases. Especially if the amount of monitoring data per unit time received by the control device via the network device increases, it will also cause When a failure occurs in the operation system, the operation system / standby system cannot be switched quickly. As described above, if the equalization of the monitoring data received by the control device via the network device is not completed, it is impossible to avoid a sudden change in the calculation result and to switch between the operation system and the standby system.

The present invention has been developed in view of the problems described above, and an object thereof is to provide a control system for a redundant control system that controls the control device even if the amount of monitoring data transmitted to each control device via a network increases. A technique that does not cause any obstacles to the execution of the original calculations, and does not reduce the switching speed of the operation system / standby system, and enables the equalization of monitoring data.

In order to solve the above problem, the present invention provides a control system that collects monitoring data from one or a plurality of devices connected to the first and second networks, and performs control based on the monitoring data. The control system includes: The following first and second control devices and first and second relay devices. The first control device and the second control device are connected by a communication means between the control devices. The communication means between the control devices is, for example, an equivalent cable, and communication between the first control device and the second control device is performed. One of the first and second control devices is an operation system and performs pre-control, and the other system is a standby system. Specific examples of the first and second relay devices include the aforementioned network devices. The first relay device is connected to the first control device and the first network, and the second relay device is connected to the second control device and the second network. The first and second relay devices are connected Communication means to the relay device. The communication means between the relay devices is, for example, an equalization cable, which mediates communication between the first relay device and the second relay device. The first and second relay devices are provided with a judging means for judging whether communication via the communication means between the relay devices is feasible. Each of the first and second relay devices transmits the monitoring data received from one or more devices to the control device of the connection target, and when it is determined by the determination means that it is communicable, it is borrowed. The communication data through the communication means of the relay device is used to equalize the monitoring data. On the other hand, when it is determined that communication cannot be performed by the determination means, the first and second relay devices perform the equalization of the monitoring data by communication through the communication means between the control devices.

In the control system of the present invention, the equalization of the monitoring data transmitted from each device to the first and second control devices is performed by the first and second relay devices. Therefore, even if the amount of data of the monitoring data increases, the processing load of each of the first and second control devices will not be excessively increased due to the equivalentization of the monitoring data. The execution of one's previous calculus will not cause any obstacles. In addition, for each of the first and second control devices, data equivalent to the first and second relay devices is given. Therefore, when one of the first and second control devices becomes the operation system and functions, and the other becomes the standby system and functions, and it is not necessary to switch the operation system / standby system due to the stop of the operation system. Waiting for the equivalentization of the monitoring data is completed, and the operation system / standby system can be switched quickly.

In the conventional redundant control system shown in FIG. 18, the equivalent of connecting the control device 10A and the control device 10B to each other once occurred If the cable 40 is cut, the monitoring data cannot be equalized at all. On the other hand, in the control system of the present invention, the communication means that mediates the data communication required for the equalization of the monitoring data is doubled by the communication means between the control devices and the communication means between the relay devices. As long as communication through any of them is feasible, the monitoring data can be equivalent without any problem. In addition, the first and second control devices can also be processed to determine whether communication through the communication means between the control devices is feasible. If possible, the status data indicating the failure of the self-device is performed through the communication means between the control devices. Send messages to monitor the other party for failures. If it is not possible, send status data to monitor the other party for failures through communication between relay devices. The relay device pair included in the control system of the present invention, that is, the relay device pair formed by the first and second relay devices that communicate through the communication means between the relay devices is of course not limited to One or plural. Specifically, it can be thought of as having: a plurality of first relay devices, each of which is connected to a plurality of first networks each having a different device connected thereto and connected to a first control device; and a plurality of second devices The relay device is a plurality of second relay devices that are paired with each of the plurality of first relay devices, respectively, and are respectively connected to the plurality of second networks connected to the above devices and are respectively connected to the second Control device; the plurality of first relay devices and the plurality of second relay devices are paired with each other to communicate through the means of communication between the relay devices.

Here, the specific implementation method of the equivalentization of the monitoring data by the communication means between the relay devices can consider various aspects. From one of the first relay device and the second relay device to the other Send monitoring data to cause the relay device of the other party to perform the process of overwriting the monitoring data received via the network with the monitoring data received through the communication means between the relay devices, that is, replacing the former monitoring data Become the processing mode of the latter monitoring data. For example, from one relay device connected to the control device of the operating system, the monitoring data is sent to the other relay device, so that the other relay device will receive the monitoring data via the network to pass The monitoring data received by the communication means between the relay devices or the communication means between the control devices is overwritten.

In another ideal aspect, considering each of the first and second relay devices, the following first and second processing means are provided. The first processing means is used to transmit the monitoring data received from the network of the connection target to the relay device of the other party. To explain in more detail, the first processing means is to transmit the monitoring data to the relay device of the other party through the communication means between the relay devices when it is judged as communicable by the above-mentioned judgment means. It sends monitoring data to the relay device of the other party through the communication means between the control devices. The second processing means is to confirm whether it can communicate with the device that is the source of the monitoring data received from the relay device of the other party. If it is impossible to communicate, the monitoring data that should have been received from the device is used to The monitoring data received from the relay device of the other party is supplemented. In the previous redundant control system, if the network connected to the relay device transmitting monitoring data to the control device of the operating system fails, or the IO host required by each machine to connect to the network fails, In both cases, it is necessary to switch between the operation system and the standby system. On the other hand, if it is based on this aspect, there is no need to Switching between the operation system and the standby system can reduce the frequency of switching between the operation system and the standby system. This point will be described in detail in the fourth embodiment of the present invention.

In a more desirable aspect, a third network is connected to either of the first and second relay devices. Then, the relay device connected to the third network collects monitoring data from the device connected to the third network, transmits the collected monitoring data to the control device of the connection destination, and transmits it to another control device. One relay device is equivalent. The details will be described in detail in the description of the third embodiment of the present invention, but various problems arise when connecting the relay device of the conventional redundant control system shown in FIG. The ground adopts this connection form. On the other hand, according to this aspect, the relay device can be easily connected to a network that has not been duplicated.

In another ideal aspect, it is characterized in that the first and second relay devices of the preamble are provided with: load measurement means for measuring a processing load imposed on the control device connected to the target; first and The second relay device is a processing load measured by the load measurement means that is greater than a predetermined threshold and judged to be communicable by the determination means, and then monitors the data by communicating through the communication means between the relay devices. Value, in other cases, the monitoring data is equalized through communication between control devices. According to such an aspect, while the processing load is distributed to each of the first and second control devices, the data communication required for the equalization of the monitoring data can be doubled.

In order to solve the above problem, the present invention is connected One of them is one of the first and second control devices that are controlled by the operation system and the other is the standby system. At the same time, it is connected to the first network connected to one or more devices that send monitoring data. The monitoring data sent by the preamble 1 or multiple devices is transmitted to the relay device of the control device connected to the target, and the following communication interface and control section are provided. The communication interface is connected to other relay devices through communication means between the relay devices. The other relay device is connected to the other one of the second network and the first and second control devices connected to the one or more devices. The control unit is, for example, a CPU (Central Processing Unit). This control unit executes the following relay processing, determination processing, and equalization processing. Relay processing is processing in which the monitoring data received from one or more devices via the first network is transmitted to the control device of the connection target. The determination processing is processing for determining whether communication can be performed through communication means between the relay devices. Then, the equalization processing is performed when the communication is determined to be communicable in the determination processing by performing communication required to equalize the monitoring data through the communication means between the relay devices. The communication is processed through the communication means between the control devices. In the redundant control system, the relay device that connects the control device and the data transmission path, that is, the network device 20A and the network device 20B in the system example shown in FIG. 18 are replaced with the ones in the present invention. The relay device can make the existing redundant control system function as the control system of the present invention.

In addition, as another aspect required for solving the above-mentioned problem, an aspect of providing a program that makes a general computer such as a CPU into the above-mentioned relay device to function is considered. This is because by following this procedure By operating a general computer, the computer can function as a relay device of the present invention. In addition, the specific patterns provided by the above-mentioned programs can be considered: the patterns distributed by downloading through electrical communication lines such as the Internet, or written to CD-ROM (Compact Disk-Read Only Memory) or flash ROMs and other computer-readable recording media and scattered.

As described above, according to the present invention, in a redundant control system, even if the amount of monitoring data transmitted to each control device via the network increases, there will be no obstacle to the execution of the original calculations of the control device. In addition, the switching speed of the operation system and the standby system is not reduced, and the monitoring data can be equivalentized.

1A, 1C, 1D‧‧‧communication system

10A, 10B, 100A, 100B, 100A ′, 100B′‧‧‧ Control device

20A, 20B, 200A, 200B, 200A ′, 200B ′, 200A ′ ′, 200B ′ ′, 200A ′ ′ ′, 200B ′ ′ ′ ‧‧‧

210‧‧‧Control Department

220‧‧‧Part 1 Communication I / F

230‧‧‧Part 2 Communication I / F

240‧‧‧Part 3 Communication I / F

250‧‧‧Memory Department

252‧‧‧Volatile Memory Department

2522‧‧‧Monitoring Data Buffer

254‧‧‧Non-volatile memory

2542, 2542 ′, 2542′′‧‧‧ Relay Control Program

2542a‧‧‧Relay processing

2542b ‧ ‧ equivalent processing

260‧‧‧Bus

30A, 30B, 30C‧‧‧IO network

40, 400, 400A, 400B‧‧‧ equivalent cables

50‧‧‧ surveillance system

S1 ~ Sn, S1 ′ ~ Sn′‧‧‧IO auxiliary device

[FIG. 1] A diagram showing a configuration example of a communication system 1A of a network device 200 including an example of a relay device of the present invention, that is, a communication system according to a first embodiment of the present invention.

[Fig. 2] A diagram showing a configuration example of the network device 200 included in the communication system 1A.

[FIG. 3] A flowchart of a flow of the equalization process 2542b performed by the control unit 210 of the same network device 200 according to the relay control program 2542.

[Fig. 4] Control unit 210 of the same network device 200 performs relay control An illustration of the action performed by program 2542.

[Fig. 5] An explanatory diagram of effects of the first embodiment.

[Fig. 6] An explanatory diagram of a modification of the first embodiment.

[FIG. 7] An explanatory diagram of another modification of the first embodiment.

[FIG. 8] A diagram showing a configuration example of a network device 200 'according to a second embodiment of the present invention.

[Fig. 9] A diagram showing a schematic configuration and an operation example of a communication system including the network device 200 '.

[FIG. 10] An explanatory diagram of a third embodiment of the present invention.

[FIG. 11] An explanatory diagram of a fourth embodiment of the present invention.

[Fig. 12] A diagram showing a configuration example of a network device 200 '"according to the fourth embodiment.

[Fig. 13] An explanatory diagram of operations performed by the control unit 210 of the same network device 200 'according to the relay control program 2542' '.

[FIG. 14] A flowchart of the flow of the equivalent reception processing 2542b2 performed by the control unit 210 in accordance with the relay control program 2542 '.

[Fig. 15] An explanatory diagram of the effect of the fourth embodiment.

[Fig. 16] An explanatory diagram of the effect of the fourth embodiment.

[Fig. 17] An explanatory diagram of a modification of the fourth embodiment.

[Fig. 18] An illustration of a previous example of the control system.

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

(A: First Embodiment)

FIG. 1 is a diagram showing a configuration example of a communication system 1A according to a first embodiment of the present invention.

This communication system 1A is a control system installed in an industrial facility in the same manner as the system shown in FIG. 18 described above. In FIG. 1, the same components as those in FIG. 18 are denoted by the same reference numerals. Comparing FIG. 1 and FIG. 18, it can be seen that the communication system 1A is different from the previous redundant control system shown in FIG. 18 in the following three points. First, instead of the control device 10A and the control device 10B, a control device 100A and a control device 100B are provided. Secondly, the network device 20A and the network device 20B are replaced with the network device 200A and the network device 200B. Then, thirdly, the network device 200A and the network device 200B are connected by the equalization cable 400.

Each of the network device 200A and the network device 200B is an embodiment of the relay device of the present invention, and the equivalent cable 400 serves as a communication means between relay devices that mediates the communication between the relay devices. Roles. The network device 200A and the network device 200B are gateway devices similar to the network device 20A or the network device 20B in FIG. 18. In the communication system 1A shown in FIG. 1, slave IO slave devices S1 and S2. ． ． The monitoring data sent by each of Sn is transmitted to the control device 100A through the IO network 30A and the network device 200A, and is transmitted to the control device 100B through the IO network 30B and the network device 200B. Each of the control device 100A and the control device 100B is the same as the control device 10A and the control device 10B in FIG. 18, and uses a slave IO slave device. S1, S2. ． ． The monitoring data collected by Sn and the past calculation results are used for calculation, that is, the calculation required for machine control and the memory of the calculation results. The control device 100A and the control device 100B may be a PLC or a DCS.

In the communication system 1A shown in FIG. 1, one of the control device 100A and the control device 100B becomes the operation system and performs control of other equipment based on the calculation result of the above. The other system becomes the standby system to prevent the stop of the operation system. As mentioned above, there are two types of stoppages in the operation system: unexpected stoppages due to certain failures or failures, or planned stoppages due to warranty repairs. Then, when the operation system is stopped, the control system of the standby system will then be operated as the operation system. In addition, the switching between the operation system and the standby system can be realized by the same method as the previous redundant control system.

As described above, in order to avoid a sudden change in calculation results when switching between the operation system and the standby system, it is necessary to equalize the monitoring data and the calculation result. In the conventional redundant control system shown in FIG. 18, the equalization of the monitoring data and the equalization of the calculation results are performed in the control device 10A and the control device 10B. In this embodiment, the equivalent of the calculation results is also executed by the control device 100A and the control device 100B, which is no different from the conventional redundant control system shown in FIG. 18. In more detail, the control device 100A and the control device 100B are operating systems, and use monitoring data received from the connected network device to perform calculations required for machine control. Data indicating the results of the calculations will be shown. , Transmitted to the other party's control via the equalization cable 40 The device equalizes the calculation result. That is, the control device of the standby system overwrites the data of the calculation result from the device with the data received through the equalization cable 40. The difference between the communication system 1A of this embodiment and the conventional redundant control system shown in FIG. 18 is that the equivalent of the monitoring data is performed on the network device 200A and the network device 200B. Hereinafter, the network device 200A and the network device 200B which prominently show the characteristics of this embodiment will be mainly described. In addition, since the network device 200A and the network device 200B have the same configuration, when there is no need to distinguish between the two, they will be referred to as "network device 200".

In this embodiment, the network device 200 is also distinguished into an operating system and a standby system. In more detail, the network device 200 communicates with the control device of its own connection target, and determines whether the control device of the connection target is an operation system. Then, the network device 200 operates as a network device of the operating system if the control device of the connection target is the operation system, and operates as a network device of the standby system if the control device of the connection target is the standby system. . That is, in the present embodiment, among the network devices 200A and 200B, a control device connected to the operation system becomes the operation system, and a control device connected to the standby system becomes the standby system. Then, once the switching between the operation system and the standby system of the control device occurs, the network device 200 also switches the operation system and the standby system in accordance with the switching. In the present embodiment, it is explained that the switching of the operation system / standby system of the network device 200 follows the switching of the operation system / standby system of the control device, but it may also be performed by transmitting equivalent values. Receive and send status data of the cable 400 to monitor the status of the other party, independent of the control device The switching of the operation system / standby system is performed, and the operation system / standby system is switched according to the result of the state monitoring.

FIG. 2 is a block diagram showing a configuration example of the network device 200.

The network device 200, as shown in FIG. 2, includes a control section 210, a first communication interface (hereinafter referred to as "I / F") section 220, a second communication I / F section 230, and a third communication I / F. The unit 240, the memory unit 250, and the bus 260 for receiving and receiving data among these constituent elements.

The control unit 210 is, for example, a CPU. The control unit 210 functions as a control center of the network device 200 by executing the relay control program 2542 stored in the storage unit 250. More correctly, the relay control program 2542 is stored in the non-volatile memory 254. The non-volatile memory section 254 is one of a plurality of constituent elements constituting the memory section 250. Details of processing executed by the control unit 210 in accordance with the relay control program 2542 will be described later. Each of the first communication I / F section 220, the second communication I / F section 230, and the third communication I / F section 240 is, for example, a NIC (Network Interface Card). The roles of these communication I / F sections are as follows.

The first communication I / F section 220 is connected to the IO network. To explain in more detail, the first communication I / F unit 220 of the network device 200A is connected to the IO network 30A, and the first communication I / F unit 220 of the network device 200B is connected to the IO network 30B. The first communication I / F unit 220 performs receiving of data transmitted from the IO network of the connection destination, and transmission of data to the IO network of the connection destination. First communication I / F section 220 It has a communication buffer that accumulates data received from the IO network to which it is connected. In FIG. 2, the illustration of the communication buffer is omitted.

The second communication I / F section 230 is connected to the control device via a communication line. To explain in more detail, the second communication I / F section 230 of the network device 200A is connected to the control device 100A, and the second communication I / F section 230 of the network device 200B is connected to the control device 100B. The second communication I / F unit 230 performs reception of data transmitted from the control device of the connection target, and transmission of data to the control device of the connection target. The second communication I / F section 230 has a communication buffer that stores data transmitted to the control device connected to the target. In FIG. 2, the illustration of the communication buffer is omitted.

The third communication I / F unit 240 has a port connected by an equalization cable, and an equalization cable 400 is connected to the port. The third communication I / F unit 240 performs communication necessary for equalizing the monitoring data with the other network device through the equalization cable 400.

The memory unit 250 includes a volatile memory unit 252 and a non-volatile memory unit 254 as shown in FIG. 2. The volatile memory section 252 is, for example, a RAM (Random Access Memory). The volatile memory section 252 is used as a work area required for execution of the relay control program 2542. The volatile memory unit 252 also functions as a monitoring data buffer 2522 that temporarily stores monitoring data transmitted to the control device. Then, the volatile memory section 252 is further stored, indicating that the network device 200 having the volatile memory section 252 is an operating system. Operation, or the operation / standby flag that operates as a standby system. The non-volatile memory section 254 is, for example, a flash ROM. The non-volatile memory section 254 stores a relay control program 2542 in advance.

The control unit 210 reads the relay control program 2542 from the non-volatile memory unit 254 to the volatile memory unit 252 when the power of the network device 200 is turned on or reset as an opportunity to start its execution. In FIG. 2, the illustration of the power source of the network device 200 is omitted. The control unit 210 that operates in accordance with the relay control program 2542 monitors the operating state of the control device connected to the target and executes the process of setting the operation / standby flag in accordance with the monitoring result. The relay process 2542a and the like Value processing 2542b. The details of the relay process 2542a and the equalization process 2542b are described in detail in the operation example, and the outline is as follows. The equalization process 2542b is a process of equalizing the monitoring data collected from each of the IO slave devices S1 to Sn through communication via the equalization cable 400. FIG. 3 is a flowchart of a flow of the equalization process 2542b. Referring to FIG. 3, it can be seen that the processing content of the equalization process 2542b is different between when the operation is performed as the operation system and when the operation is performed as the standby system. The details of the processing performed by the equalization processing 2542b are described in detail in the description of the operation example. The relay process 2542a is a process of transmitting monitoring data that has been equalized by the equalization process 2542b to a control device connected to the second communication I / F unit 230.

The above is the configuration of the network device 200.

Next, the operation of the network device 200 will be described with reference to FIGS. 3 and 4. In the operation example described below, it is assumed that the control The control device 100A and the network device 200A are operating systems, and the control device 100B and the network device 200B are standby systems. In the operation example described below, a case where the monitoring data buffer 2522 of each of the network device 200A and the network device 200B is empty at the start point of the operation will be described.

Each of the IO auxiliary device devices S1 to Sn generates monitoring data for sampling each of an input signal or an output signal of a sensor and the like, and sends the monitoring data to each of the control device 100A and the control device 100B to the IO network. Each of 30A and IO network 30B performs transmission. The monitoring data sent to the IO auxiliary device devices S1 to Sn is provided with headers including information indicating the transmission target and transmission source of the monitoring data, and identifying elements for non-discriminatory display of the monitoring data. Specific examples of the information indicating the transmission destination of the monitoring data include, for example, the communication address or node number of the machine to which the transmission destination is transmitted. The same goes for information indicating the source of the surveillance data. The monitoring data sent from each of the IO slave devices S1 to Sn is transmitted to each of the network device 200A and the network device 200B through each of the IO network 30A and the IO network 30B. . Hereinafter, the monitoring data transmitted to the network device 200A is referred to as "monitoring data A", and the monitoring data transmitted to the network device 200B is referred to as "monitoring data B". The monitoring data A and the monitoring data B are basically the same data, but sometimes they may be slightly different due to the sampling timing error during sampling.

Once the first communication I / F section 220 of the network device 200A receives the monitoring data sent from the IO network 30A, the received monitoring data is written to the first communication I / F section 220 Internal communication Information buffer. Similarly in the network device 200B, the monitoring data received from the IO network 30B is written in the communication buffer of the first communication I / F unit 220 of the network device 200B. That is, in this operation example, the monitoring buffer A is stored in the communication buffer in the first communication I / F section 220 of the network device 200A, and the monitoring data A is stored in the first communication I / F section 220 of the network device 200B. Monitoring data B is stored in the communication buffer.

The control unit 210 of the network device 200A is the opportunity to write the monitoring data of the communication buffer in the first communication I / F unit 220 in the past, in other words, to receive the monitoring data from the IO network 30A of the connection target. As an opportunity, relay processing 2542a is executed. As shown in FIG. 4, in the relay processing 2542 a, the control unit 210 reads the monitoring data from the communication buffer in the first communication I / F unit 220 (FIG. 4 (A): S100), and sends the monitoring data to the monitoring data. The buffer data is written into the buffer 2522 (FIG. 4 (A): S110). Therefore, in this operation example, the monitoring data A is stored in the monitoring data buffer 2522 of the network device 200A. The processing of S100 and S110 is similarly performed in the network device 200B (see FIG. 4 (B)), and the monitoring data B is stored in the monitoring data buffer 2522. In addition, when writing monitoring data into the monitoring data buffer 2522, the control unit 210 sets a first value indicating that the value has not been equalized to a flag indicating whether it has been equalized, and sets the value to The flag of the first value is assigned to the above-mentioned monitoring data and then written into the monitoring data buffer 2522. A specific example of the first value is, for example, 0.

In the network device 200A, the control unit 210 buffers the monitoring data with the monitoring data that has been given a flag indicating that it has not been equalized. The writing of the area 2522 is an opportunity to perform the equalization process 2542b. As shown in FIG. 3, in the equalization process 2542b, the control unit 210 first determines whether the own device is operating as an operation system (step SA100). Specifically, the control unit 210 refers to the operation / standby flag stored in the volatile memory unit 252, and if the value of the flag is a value indicating the operation system, it determines that the own device operates as the operation system. Then, if the determination result of step SA100 is "Yes", the control unit 210 executes the processing of step SA110, otherwise, if the determination result of step SA100 is "No", the control unit 210 executes the processing of step SA120 onward. As described above, in this operation example, the network device 200A operates as an operation system. Therefore, in the equivalent processing 2542b performed by the control unit 210 of the network device 200A, the determination result of step SA100 is "Yes", and the processing of step SA110 is performed.

In step SA110 that is executed when the determination result of step SA100 is "Yes", the control unit 210 reads the monitoring data that has been given a flag indicating that it has not been equalized from the monitoring data buffer 2522 (Figure 4 (A): S120). The monitoring data is transmitted to the network device to which it is connected through the third communication I / F unit 240 (FIG. 4 (A): S130). As described above, the monitoring data buffer 2522 of the network device 200A stores the monitoring data A as the monitoring data that has been given a flag indicating that it has not been equalized. Therefore, in this operation example, the monitoring data A is transmitted from the network device 200A to the network device 200B through the equalization cable 400.

In the network device 200B, the control unit 210 is the third communication I / F unit 240 with the data transmitted through the equalization cable 400. The reception is an opportunity to perform the equalization process 2542b. In the equalization process 2542b performed by the control unit 210 of the network device 200B, the determination of step SA100 described above is also performed. In this operation example, the network device 200B operates as a standby system. Therefore, the determination result of step SA100 of the equalization process 2542b performed by the control unit 210 of the network device 200B is "No" and executed. Processing after step SA120. In step SA120, the control unit 210 obtains the monitoring data that has been received by the third communication I / F unit 240 from the third communication I / F unit 240 (FIG. 4 (B): S140), and This monitoring data overwrites the appropriate monitoring data stored in the monitoring data buffer 2522 (Figure 4 (B): S150), and rewrites the flag given to the monitoring data to a second value indicating that it has been equivalent. . The so-called proper monitoring data is the same as the monitoring data obtained from S140 in FIG. 4 (B), and the identifier is the same monitoring data. As a specific example of the second value described above, for example, 1. Thereby, the monitoring data stored in the monitoring data buffer 2522 of the network device 200B is updated from the monitoring data B to the monitoring data A.

The control unit 210 of the network device 200B once the monitoring data is equalized using the above-mentioned method, the equalization is completed through the equalization cable 400, and the network device 200A is notified (Fig. 3: Steps) SA130). The control unit 210 of the network device 200A updates the flag of the monitoring data transmitted in S130 of FIG. 4 (A) to the second value of the above-mentioned notification as an opportunity to receive the notification from the above notification. As a result of the above operations, the monitoring data buffer 2522 of each of the network device 200A and the network device 200B stores monitoring data A, and the monitoring data A is The state is given a flag indicating that it has been equalized.

The control unit 210 of the network device 200A restarts the relay processing 2542a with the flag given by the monitoring data stored in the monitoring data buffer 2522 being updated to indicate that the value has been equalized, and executes the diagram. Each process of S160 and S170 of 4 (A). In the process of S160, the control unit 210 reads the monitoring data with the flag indicating that it has been equalized from the monitoring data buffer 2522. Then, in the process of S170, the control unit 210 writes the monitoring data read by S160 into the communication buffer of the second communication I / F unit 230. In the network device 200B, relay processing 2542a is started again with the transmission of the notification of the equivalent completion as an opportunity, and each processing of S160 and S170 of FIG. 4 (B) is executed.

The second communication I / F section 230 of the network device 200A is a monitoring device that writes the above-mentioned methods into the communication buffer and sends it to the control device of the connection destination. Similarly, the second communication I / F unit 230 of the network device 200B sends the monitoring data written in the communication buffer to the control device of the connection destination. Therefore, in this operation example, the monitoring data A is transmitted from the network device 200A to the control device 100A, and the monitoring data A is also transmitted from the network device 200B to the control device 100B. In addition, compared with the sending and receiving of monitoring data, the sending and receiving of the above notification is performed at a very high speed, so the updating of the above flag in each of the network device 200A and the network device 200B is slightly synchronized. Execution, the processes of S160 and S170 are also executed slightly synchronously. Therefore, the monitoring data A is transmitted from the network device 200A to the control device 100A, and the monitoring data A is transmitted from the network device 200B to the control device 100B. The system is executed almost synchronously.

The above is the operation of this embodiment.

In the conventional redundant control system shown in FIG. 18, since the equivalent of the monitoring data is performed by the control device, that is, the control device 10A and the control device 10B, once the data amount of the monitoring data increases, the control The processing load of the device will be higher than the equivalent weight, which will cause obstacles to the high-speed execution of the original calculation. This is a problem. FIG. 5 is a schematic diagram of a communication system 1A according to this embodiment. In this embodiment, the equalization of the calculation results is performed by the control device 100A and the control device 100B through the communication via the equalization cable 40 in FIG. 5, but the equalization of the monitoring data is The communication is performed by the network device 200A and the network device 200B through the equalization cable 400 in FIG. 5. Therefore, even if the amount of data on the monitoring data transmitted by the control device 100A and the control device 100B increases due to an increase in the number of IO slave devices connected to the IO network, the amount of data imposed on the control device 100A and the control device 100B is increased. The processing load will not exceed the value of this value, and the implementation of the original calculation will not cause any obstacles.

Furthermore, in this embodiment, the monitoring data that has been equalized through the communication line LA in FIG. 5 is transmitted from the network device 200A to the control device 100A, and is equivalentized through the communication line LB in FIG. 5. The monitoring data is transmitted from the network device 200B to the control device 100B. Then, the equalization of the calculation result based on the monitoring data is realized by communication through the equalization cable 40 in FIG. 5. Since the monitoring data of the control device 100A and the control device 100B have been equalized, they are transmitted. In the past, even if the operation system / standby system is switched due to the stop of the operation system control device, the control device does not need to wait for the equalization of the monitoring data to be completed, and can be immediately switched. That is, according to this embodiment, the switching speed of the operation system / standby system does not decrease.

Based on the above description, according to this embodiment, a control system can be provided that collects monitoring data from one or a plurality of devices connected to the first and second networks, and performs control control based on the monitoring data. The system is characterized in that: one of the first and second control devices is controlled by the operation system and the other is the standby system; and the first relay device is connected to the first control device and the first control device. 1 network; and a second relay device connected to the second control device and the second network; and a communication means between the control devices is used to mediate the communication between the first control device and the second control device; and Inter-device communication means is used to mediate the communication between the first relay device and the second relay device; each of the first and second relay devices is the monitoring received from one or more machines. The data is transmitted to the control device of the connection target, and the communication required for equalizing the monitoring data is performed through communication means between the relay devices. The first control device and the second control device are the operating systems. , Use the slave connection The standard relay device received the required data to the monitoring control calculation, calculation results using the means of communication between the control means and transmitted to the control device as a standby system and will be the equivalent of calculation results. That is, in the present invention, one of the first control device and the second control device, which is an operation system, uses the monitoring data received from the relay device connected to the target to perform calculations required for control, and performs the calculations. Result through the control device The communication means is transmitted to the control device which is a standby system. Therefore, it is possible to equalize only calculation results that do not include monitoring data in the control room. In other words, between the control devices of the present invention, only the calculation results can be equalized. Therefore, according to this embodiment, in the redundant control system, even if the amount of data of the monitoring data transmitted to the control device increases, the execution of the original calculation of the control device will not cause any obstacles and will not cause The switching speed between the operation system and the standby system is reduced.

In the conventional redundant control system shown in FIG. 18, the intermediary means of data communication between the operation system and the standby system is equivalent to the inter-controller communication means that only communicates between the intermediary control devices. The cable 40 is only used. Therefore, once the equivalent cable 40 is disconnected, the operation system and the standby system cannot communicate with each other, and even the communication required for monitoring the status cannot be performed. Therefore, in the previous redundant control system, once the equalization cable 40 was disconnected, first, the switching between the operation system and the standby system could not be performed, and then if the control system of the operation system failed, it was also called When multiple faults occur, there is a problem that the machine cannot be controlled at all.

On the other hand, in this embodiment, the intermediary means for data communication between the operation system and the standby system is doubled by the equalization cable 40 and the equalization cable 400, even if the equalization occurs The disconnection of the cable 40 does not prevent communication required to monitor the status of each other. For example, even when the equalizing cable 40 is cut at the position indicated by the symbol B in FIG. 6, the control system of the present embodiment can still be performed along the path C1 indicated by the dotted arrow in FIG. 6. Delivery of status data. With Specifically, the control device 100A is executed, and the status data indicating the status of the own device is transmitted to the control through the communication line LA, the network device 200A, the equivalent cable 400, the network device 200B, and the communication line LB. The processing of the device 100B causes the control device 100B to execute and send status data indicating the status of the device to the control via the communication line LB, the network device 200B, the equivalent cable 400, the network device 200A, and the communication line LA. The processing of the device 100A is sufficient.

In addition, in the embodiment described above, although one control device is connected to one network device, as shown in FIG. 7, one control device may be modified by connecting a plurality of network devices. In the system shown in Fig. 7, two network devices are connected to one control device. This is because in the previous redundant control system, if a plurality of network devices were connected to the control device, the amount of data of the monitoring data transmitted to the control device would increase, which would hinder the execution of the original calculation of the control device. Defects such as a decrease in the switching speed of the operation system / standby system occur, but in the present embodiment, such problems do not occur.

As shown in FIG. 7, even when a plurality of network devices 200 are connected to one control device, each of the network device 200A and the network device 200B goes to each of the control device 100A and the control device 100B. The equalization of the monitoring data transmitted by the user is performed by these network devices through communication through the equalization cable 400A, and to the control device through each of the network device 200C and the network device 200D. The equalization of the monitoring data transmitted by each of the 100A and the control device 100B is performed by these network devices through communication through the equalization cable 400B. Row. Therefore, even if the amount of data of the monitoring data transmitted to the control device increases due to the connection of a plurality of network devices to one control device, the processing load of the control device will not be higher than the equivalent value.

(B: Second embodiment)

In the first embodiment described above, the case where the network device 200A and the network device 200B are equalized by the communication through the equalization cable 400 is described. However, if the equalization cable 400 is cut in such an aspect, there is a problem that the equalization of the monitoring data cannot be performed. The network device 200A ′ and the network device 200B ′ of this embodiment are intended to solve this problem. The network device 200A ′ and the network device 200B ′ of this embodiment determine whether data communication through the equalization cable 400 is possible. If a possible determination result is obtained, data communication through the equalization cable 400 is performed. Instead, the monitoring data is equivalentized. On the other hand, if an impossible determination result is obtained, the network device 200A ′ and the network device 200B ′ perform monitoring data by communicating through the control device 100A, the equivalent cable 40, and the control device 100B. Equivalent. Hereinafter, when it is not necessary to distinguish between the network device 200A ′ and the network device 200B ′, it is simply referred to as “network device 200 ′”.

FIG. 8 is a diagram showing a configuration example of the network device 200 '. It can be seen from the comparison between FIG. 8 and FIG. 2 that the configuration of the network device 200 ′ is to replace the relay control program 2542 to the relay control program 2542 ′, which is stored in the non-volatile memory section 254. The configuration of the road device 200 is different. The relay control program 2542 'instructs the control unit 210 to execute relay processing 2542a, Programs for the equalization process 2542b 'and the determination process 2542c. The determination processing 2542c is a processing for determining whether communication through the communication means between the relay devices, that is, the equalization cable 400 is feasible. The equalization process 2542b ′ means that when it is determined that communication is possible in the determination process 2542c, communication required for equalizing the monitoring data is performed through communication means between relay devices. On the other hand, when it is determined that communication is not possible The communication is performed through the communication means between the control devices, that is, the equalization cable 40. That is, the control unit 210 that operates in accordance with the relay control program 2542 ′ is a relay means that executes the relay process 2542a, a judgment means that executes the judgment process 2542c, and an equivalent means that executes the equalization process 2542b ′. And function.

FIG. 9 is a diagram showing a schematic configuration and an operation example of a control system including a network device 200 '. In addition, in FIG. 9, the network device is abbreviated as “NW device”. In addition, in order to clarify the characteristics of the present embodiment, FIG. 9 clearly shows that the network device 200 'has a determination means. If the equalization cable 400 is disconnected at the position shown by the symbol B in FIG. 9, the network device 200A ′ and the network device 200B ′ cannot communicate through the equalization cable 400. In this case, the network device 200A ′ and the network device 200B ′ perform data communication along the communication path C2 indicated by the dotted arrow in FIG. 9, and perform equalization of the monitoring data. To explain in more detail, the network device 200A ′ is the monitoring data received from the IO network 30A, along the communication line LA, the control device 100A, the equivalent cable 40, the control device 100B, and the communication line in this order. The transmission path formed by the LB is transmitted to the network device 200B ′. The network device 200B ′ receives the above monitoring data, and overwrites the corresponding monitoring data from the device with the monitoring data, and completes the equivalent. Return the notification. The equivalent completion notification sent back from the network device 200B ′ is transmitted to the network along the communication line LB, the control device 100B, the equalization cable 40, the control device 100A, and the communication line LA in this order. The device 200A ′ completes the equalization of the monitoring data.

In this embodiment, the control device 100A and the control device 100B only have the function of the data transmission path of the data communication required for the equalization of the mediator. Therefore, compared with the case of the previous redundant control system, it is possible to reduce these problems. The processing load imposed by the control device. As a specific example of the above-mentioned determination processing 2542c, for example, a ping is sent to the counterpart device through the equalization cable 400. If there is a response within a predetermined time, it is determined to be communicable. If there is no response, it is determined to be unable to communicate. Processing. In addition, the transmission and reception of status data between the control device 100A and the control device 100B is also possible, and the transmission path may be switched in accordance with the availability of data communication through the equalization cable 40. Specifically, each of the control device 100A and the control device 100B can also be executed: if the data communication through the valued cable 40 is possible, the status data is sent to the other control device through the valued cable 40 If it is not possible, the process of sending status data to the control device of the other party through the equalization cable 400 is performed.

Whether the data communication required for the equalization of the monitoring data is to be switched via the equalization cable 400, or is to be switched via the equalization cable 40, or it may not be the same as passing through the equalization cable 400. Whether the data communication can be switched or not, but the state of switching according to the processing load of the control device. For example, if the network device 200 'measures the processing load of the control device connected to the target, and if the measured processing load does not reach a predetermined threshold, then The monitoring data is equalized by the data communication between each control device of the operation system and the standby system and the equalization cable 40. If the processing load of the control device is equal to or greater than a predetermined threshold, the data is transmitted through the equalization cable. The data communication of the line 400 is used to perform the equivalent of the monitoring data; the control unit of each network device of the operation system and the standby system may perform the above processing. Here, as a specific measurement method of the processing load of the control device, consideration is given to obtaining data indicating the CPU usage rate or the memory usage rate of the control device from the control device of the connection target, and causing the network device 200 to execute Aspects of the above processing. Furthermore, the availability of data communication through the equalization cable 400 and the processing load of the control device can be used in combination to switch the transmission path of the monitoring data. Specifically, if the processing load of the control device is equal to or higher than a predetermined threshold and the communication through the equalization cable 400 is determined to be possible, the monitoring data and the like are transmitted through the communication through the equalization cable 400. Value, in other cases, that is, when the processing load of the control device does not reach the predetermined threshold value, or when the processing load is above the predetermined threshold value but the communication through the equalization cable 400 is not possible, The communication of the cable 40 may be performed to equalize the monitoring data.

In addition, for each IO auxiliary device device that sends the monitoring data, is the monitoring device equivalent to the monitoring data or the relay device side, that is, the division modal system on the network device side. It may be specified in advance so that the processing load on the equalization of the monitoring data is distributed between the control device and the network device. For example, the monitoring data sent from the IO slave device S1 is equivalent on the control device side, and the monitoring data sent from the IO slave device S2 is monitored on the network device side to This way. In this way, corresponding to the communication address of each IO slave device, a division modal table indicating a flag indicating which of the control device side and the network device side is to be equivalent to the monitoring data is stored. It is stored in advance in the control devices 100A and 100B and the network devices 200A ′ and 200B ′. Then, the network devices 200A ′ and 200B ′ are equalized with respect to the monitoring data specified in the division table to be equalized at the relay device side, and the control devices 100A and 100B are directed at the division The table specifies that monitoring data to be equivalentized on the control device side may be equivalentized. In addition, a plurality of the above-mentioned division tables may be prepared in accordance with the processing load of the control device, and it is designed so that the more corresponding to the table with a high processing load, the monitoring data equivalent to the relay device is stored. The more content there is.

(C: Third Embodiment)

Fig. 10 is a diagram showing a configuration example of a communication system 1C according to a third embodiment of the present invention.

This communication system 1C is also a control system installed in an industrial facility. In FIG. 10, the same elements as those in FIG. 1 are denoted by the same reference numerals. It can be seen from the comparison between FIG. 10 and FIG. 1 that the communication system 1C is different from the communication system 1A in the following three points. First, the control device 100A ′ and the control device 100B ′ are provided instead of the control device 100A and the control device 100B. Secondly, instead of the network device 200A and the network device 200B, the network device 200A ′ ′ and the network device 200B ′ ′ are installed instead. Thirdly, the IO network 30C is connected to the network device 200A ′.

On the IO network 30C, IO slave devices S1 ′ to Sn ′ are connected. The IO network 30C is a data communication between the IO slave device S1 ′ ~ Sn ′ and the network device 200A ′ ′. As described above, the network transmitting the data sent from the IO slave device devices S1 to Sn to the control device is doubled by the IO network 30A and IO network 30B, but from the IO slave device S1 ′ The network system where the data sent by ~ Sn ′ is transmitted to the control device has not been subjected to such a duplication. That is, the network device 200A ′ is connected to a network that has been duplexed and a network that has not been duplexed. Hereinafter, a network that has not been duplicated is referred to as a "separate network."

The network device 200A ′ ′ is similar to the network device 200A in the first embodiment, and relays data communication between the IO network 30A and the control device 100A ′. Similarly to the network device 200B in the first embodiment, the network device 200B ′ ′ relays data communication between the IO network 30B and the control device 100B ′. In addition, the network device 200A ′ ′ and the network device 200B ′ ′ are similar to the network device 200A ′ and the network device 200B ′ in the second embodiment, and data communication is performed through the equalization cable 400. Instead, the monitoring data is equivalentized. However, the network device 200A ′ ′ and the network device 200B ′ ′ switch the operation system / standby system by monitoring the status of each other regardless of whether the control device of the connection target is the operation system or the standby system. It is different from the network device 200.

In addition, the network device 200A ′ ′ and the network device 200B ′ ′ perform the same processing on the monitoring data received from the IO network 30C as the equivalent of the above. In other words, the control unit of the network device 200A ′ ′ monitors the monitoring data received from the IO network 30C through the equivalent value. The cable 400 is transmitted to the network device 200B ′ ′, and the control unit of the network device 200B ′ ′ writes the monitoring data into the monitoring data buffer. Then, each of the network device 200A ′ ′ and the network device 200B ′ ′ sends the monitoring data sent from the IO network 30C to the control device of each connection target.

The control device 100A ′ and the control device 100B ′ are based on the receiving of the data transmitted from the IO slave devices S1 to Sn as an opportunity to respond to the first calculation using the data and the calculation result of the first calculation. Instead, control of the machine is performed. In addition, the control system of the operation system takes the opportunity of receiving the data transmitted from the IO auxiliary device devices S1 ′ to Sn ′ as an opportunity to perform the second calculation using the data. That is, the control device of the operation system in the present embodiment also plays a role of collecting data from the IO auxiliary device devices S1 to Sn and performing the first calculation, and collecting data from the IO auxiliary device devices S1 ′ to Sn ′ and performing the first operation. The role of 2 calculus.

In a redundant control system, a control device that collects data from an IO slave device and performs some calculations via a network that has been dualized can serve the role of collecting data and performing other calculations through a separate network. It is expected to reduce the cost of system development and operation by separately setting up a system for dual network and separate network, but it is difficult to meet such expectations in the previous redundant control system. The reason is as follows.

For example, it is assumed that only the network device 20A in FIG. 18 is connected to a separate network. In this case, from the network device 20A to the control device 10A, the data received from the separate network and the data received from the network that has been doubled are given. On the other hand, from the network device 20B To control Setting 10B only gives the data received from the network that has been doubled. Once the data given to the control device 10A and the control device 10B are inconsistent, an error will be determined in the redundant control system. In such a system, the connection form as described above cannot be adopted originally.

In addition, even if the above-mentioned inconsistency is not determined as an error, as in the above-mentioned connection mode, if the operation system / standby system is switched due to a failure of the control system of the operation system, etc., the operation after the switching is performed The control device of the system will not give the receiving data from the separate network, and the calculation of collecting and using the data sent from the separate network will not continue. That is, even if one of the dual control devices included in the previous redundant control system is given data via a separate network to enable it to perform a predetermined calculation, there is no guarantee that the calculation can be performed stably.

On the other hand, according to this embodiment, even if the switching of the operation system / standby system of the control device occurs, the control device system of the switched operation system will be inherited by the monitoring data received from the separate network. The collection of the surveillance data and the calculations using the data can continue without problems. For example, in the communication system 1C shown in FIG. 10, even if the operation system is switched from the control device 100A ′ to the control device 100B ′, the network device 200A ′ ′ is still a relay device of the operation system, and the network device 200B ′ ′ The system is still a standby device. Therefore, the monitoring data sent from each of the IO slave devices S1 ′ to Sn ′ is based on the IO network 30C → the network device 200A ′ ′ → the equivalent cable 400 → the network device 200B ′ ′ → The control device 100B ′ is transmitted to the control device 100B ′. That is, if According to this embodiment, a control device that can collect data from an IO slave device and perform a certain calculation in a redundant control system via a network that has been doubled can also perform data collection and data collection through a separate network. Compared with the case of separately setting up a dual network system and a separate network system, it can reduce the cost of system development and use. In addition, in a case where the switching of the operation system / standby system of the network device follows the switching of the operation system / standby system of the control device, as long as the network device connected to a separate network is made, regardless of the network device Whether it is an operating system, the monitoring data received through the separate network will be transmitted to the network device of the other party through the communication means between the relay devices or the communication means between the control devices, so that they can perform the monitoring data, etc. The value can be processed.

(D: Fourth Embodiment)

Fig. 11 is a diagram showing a configuration example of a communication system 1D according to a fourth embodiment of the present invention.

This communication system 1D is also a control system installed in an industrial facility. In FIG. 11, the same elements as those in FIG. 1 are denoted by the same symbols. FIG. 11 is a diagram showing the detailed connection state of the IO slave devices S1 to S3 of the IO networks 30A and 30B, which is different from FIG. 1. As shown in FIG. 11, each of the IO slave devices Sn (n = 1 to 3) is connected to the IO network 30A through the IO host MAn, and is connected to the IO network 30B through the IO host MBn. In addition, in FIG. 11, the IO host system is abbreviated as "IOM". The IO master MAn sends monitoring data output by the IO slave device Sn to the IO network 30A. IO host MBn, is the IO The monitoring data output by the slave device Sn is sent to the IO network 30B. In addition, in FIG. 1, the illustration of the detailed connection form of the IO slave devices S1 to Sn is omitted, but is the same as that in FIG. 11.

It can be seen from the comparison between FIG. 11 and FIG. 1 that the communication system 1D replaces the network device 200A and the network device 200B with the network device 200A ′ and the network device 200B ′ ′. The communication system 1A of the first embodiment is different. The network device 200A ′ ′ and the network device 200B ′ ′ ′ of this embodiment also operate as an operating system and the other operates as a standby system. In this embodiment, as in the first embodiment described above, among the network device 200A ′ ′ and the network device 200B ′ ′ ′, one of the control devices 100 connected to the operation system is an operation system. Identity. Hereinafter, as in the description of the first embodiment, when there is no need to distinguish between the network device 200A ′ ′ ′ and the network device 200B ′ ′ ′, it is abbreviated as “network device 200 ′ ″”.

In the conventional redundant control system shown in FIG. 18, it is assumed that the control system of the operation system has some trouble. Even if it is connected to the IO network of the control system of the operation system through the network device, When some kind of trouble occurs on the IO host connected to the IO slave device in this IO network, it is necessary to switch between the operation system and the standby system. This is because if the IO network or IO host fails, the monitoring data via the IO network or IO host cannot reach the control device of the operation system. On the other hand, in this embodiment, the network device 200 ′ ′ ′ is allowed to execute the processing peculiar to this embodiment, and it can be configured so that even if some trouble occurs in the IO network or IO host described above, it is not necessary to perform Switching between running / standby system can continue to control The control of the target device is a feature of this embodiment. In the following, a network device 200 ′ ″ that significantly shows the characteristics of this embodiment will be described.

FIG. 12 is a diagram showing a configuration example of a network device 200 '. In FIG. 12, the same components as those in FIG. 2 are denoted by the same reference numerals. As can be seen from the comparison between FIG. 12 and FIG. 2, the configuration of the network device 200 ′ ″ is replaced by the relay control program 2542 and the relay control program 2542 is stored in the non-volatile memory section 254. Is different from the composition of the network device 200. The relay control program 2542 is used in place of the equalization process 2542b and instead causes the control unit 210 to execute the equalization transmission process 2542b1 and the equalization reception process 2542b2, which is the same as that in the first embodiment. Following the control program 2542 is different.

The control unit 210 of the network device 200 ′ reads from the non-volatile memory portion 254 to the volatile memory portion 252 by turning on or resetting the power supply (not shown) of the network device 200 ′ as an opportunity. Out of the relay control program 2542 "and start its execution. FIG. 13 is an explanatory diagram of an operation performed by the control unit 210 of the network device 200 'according to the relay control program 2542'. In FIG. 13, the same processes as those in FIG. 4 are denoted by the same symbols. The control unit 210 which operates in accordance with the relay control program 2542 ′ is the same as the control unit 210 in the first embodiment described above, and monitors data to the communication buffer in the first communication I / F unit 220. Writing is an opportunity, that is, the receiving process of monitoring data from the IO network 30 connected to the target is used as an opportunity to perform the relay processing 2542a. As described above, in the relay processing 2542a, the control unit 210 reads monitoring data from the communication buffer in the first communication I / F unit 220 (FIG. 13: S100), and writes the monitoring data to the monitoring data buffer 2522. Data (Figure 13: S110). In addition, when writing monitoring data to the monitoring data buffer 2522, a flag indicating a first value that has not been equalized is set and written to the monitoring data buffer 2522. This is also the same as the first embodiment. the same.

It can be seen from the comparison between FIG. 13 and FIG. 4 that the combination of the equalization transmission processing 2542b1 and the equalization reception processing 2542b2 corresponds to the equalization processing 2542b. The execution opportunity of the equalization process 2542b in the first embodiment is different between the network device in the operation system and the network device in the standby system. For example, in the operation system, the equalization process 2542b is performed based on the writing of the monitoring data buffer 2522 to the monitoring data that has been given a flag indicating that it has not been equalized. In the standby system, the equivalent value is transmitted When the cable 400 is received and the monitoring data is received, the equivalence processing 2542b is executed. In contrast, the execution opportunity of the equivalent transmission processing 2542b1 is not different between the network device of the operation system and the network device of the standby system, and the execution opportunity of the equivalent reception processing 2542b2 is also different.

To explain in more detail, the control unit 210 of the network device 200 ′, regardless of whether it operates as an operating system or not, uses the monitoring data that has been given a flag indicating that it has not been equivalent to the monitoring data buffer. The writing of 2522 is an opportunity to perform the equivalent transmission process 2542b1. In the equalization transmission process 2542b1, the control unit 210 reads out the monitoring data (FIG. 13: S120) to which the flag indicating that it has not been equalized is read from the monitoring data buffer 2522, and gives the monitoring data to the first 3Communication I / F section 240 (Figure 13: S130) is transmitted to the other network device. Therefore, in this embodiment, the network device 200A is received from the IO network 30A. The received monitoring data A is transmitted to the network device 200B ′ through the equalization cable 400. The monitoring data B received by the network device 200B ′ from the IO network 30B is also transmitted through the equalization cable. The line 400 is transmitted to the network device 200A '".

The control unit 210, which operates in accordance with the relay control program 2542 ′ ′, performs the equalization receiving based on the opportunity to receive monitoring data from the other network device 200 ′ ′ through the equalization cable 400. News processing 2542b2. FIG. 14 is a flowchart of the process of the equivalent receiving process 2542b2. As shown in FIG. 14, the control unit 210 first determines whether the IO slave device is the source of the monitoring data received from the other network device 200 ′ ′ through the equivalent cable 400. Is communication possible (step SB100). A specific method for determining whether communication with the IO slave device of the source of the above-mentioned monitoring data is possible is to consider using an existing technology such as ping.

If the determination result of step SB100 is "No", that is, when communication is not possible, the control unit 210 uses the monitoring data received from the other network device 200 ′ ′ through the equivalent cable 400, The monitoring data that should be received through the IO network 30 of the connection target of the self-device, that is, the monitoring data sent to the control device 100 connected to the self-device, is supplemented (step SB110). Since it cannot communicate with the IO auxiliary device, it will not receive the monitoring data from the IO auxiliary device. Step SB110 is used to make up the processing required for the defect of the monitoring data. To explain in more detail, in step SB110, the control unit 210 sends a message indicating the header of the monitoring data received through the equalization cable 400. The target information is rewritten into information indicating that the control device 100 is connected to the own device, and a flag indicating that the first value has not been equalized is set and written into the monitor data buffer 2522. Next, the control unit 210 updates the flag of the monitoring data written in the monitoring data buffer 2522 in step SB110 to a second value indicating that it has been equalized, and notifies the completion of the equalization. The other network device (step SB150) completes the equivalent reception processing 2542b2. In addition, as described above, when the determination result of step SB100 is "No", since the monitoring data of the other party's network device 200 '"is not transmitted via the equalization cable 400, as long as the other party's The receiving of the above notification in the network device is an opportunity and the detection and equivalentization is completed, and the flag of the current monitoring data can be updated.

On the other hand, if the determination result of step SB100 is "Yes", that is, when communication is possible, the control unit 210 determines whether the own device is an operating system in the same manner as in step SA100 described above (step SB120). If the determination result of step SB120 is "Yes", that is, when the self-device is an operating system, the control unit 210 will monitor the received from the other network device 200 'through the equalization cable 400. The data is discarded (step SB130), and then the equivalent flag of the monitoring data written to the monitoring data buffer 2522 corresponding to the monitoring data is updated to a second value (step SB150), and the equivalent is ended Chemical reception processing 2542b2. On the other hand, if the determination result of step SB120 is “No”, that is, when the self-device is a standby system, the control unit 210 system performs the same processing as that of step SA120 to pass from the network of the other party through the equalization cable 400 The monitoring data received by the road device 200 ′ will be written to the monitoring as corresponding to the monitoring data The monitoring data in the data buffer 2522 is replaced (step SB140), and thereafter, the processing in step SB150 is executed to end the equivalent reception processing 2542b2.

The above is the configuration of the network device 200 '.

Next, this embodiment will be described using the control device 100A as the operation system and the control device 100B as the standby system, that is, when the network device 200A ′ ′ ′ is the operation system and the network device 200B ′ ″ is the standby system. Actions. If both IO host MAn (n = 1 ~ 3) and IO host MBn (n = 1 ~ 3) are operating soundly, and there are no obstacles such as disconnection in IO network 30A and IO network 30B, then from IO The monitoring data An sent by the slave device Sn (n = 1 ~ 3) is the monitoring data Bn sent from the IO slave device Sn to the network device 200A through the IO network 30A. It reaches the network device 200B 'through the IO network 30B.

As described above, in each of the network device 200A ′ ′ and the network device 200B ′ ′ ′, relay processing 2542a is executed with the opportunity to receive monitoring data through the first communication I / F unit 220. . As a result, as shown in FIG. 15 (A), the monitoring data An in the monitoring data buffer 2522 of the network device 200A ′ is stored in the monitoring data buffer 2522 in the network device 200B ′. The monitoring data Bn is stored. In addition, taking the opportunity to write the monitoring data that has not been equalized to the monitoring data buffer 2522, the network device 200 '"will perform the equivalent transmission process 2542b1. As a result, as shown in FIG. 15 (A), the monitoring data An is transmitted from the network device 200A ′ ′ to the network device 200B ′ ′ via the equalization cable 400, and from the network device 200B ′ ′ to the network. The channel device 200A 'transmits the monitoring data Bn via the equalization cable 400.

As described above, each time the control unit 210 of the network device 200 ′ ′ receives the monitoring data through the third communication I / F unit 240, it performs the equivalent reception processing 2542 b 2. Specifically, each time the control unit 210 of the network device 200A ′ receives the monitoring data Bn through the third communication I / F unit 240, it performs the equivalent reception processing 2542b2. In this operation example, all of the IO hosts MAn (n = 1 to 3) are operating soundly, and there are no obstacles such as disconnection on the IO network 30A. Therefore, in the equivalent reception processing 2542b2 performed by the control unit 210 of the network device 200A ′, the determination result of step SB100 is “Yes”, and the processing after step SB120 is performed. The network device 200A ′ is an operating system, so the determination result of step SB120 is “Yes”, and the processing of step SB130 is executed. That is, all the monitoring data Bn received by the network device 200A ′ through the third communication I / F unit 240 are discarded.

The same applies to the network device 200B ′ ′, and each time the monitoring data An is received through the third communication I / F section 240, the equivalent reception processing 2542b2 is performed. The equivalent reception processing 2542b2 performed by the control unit 210 of the network device 200B ′ is also performed. The determination result of step SB100 is “Yes”, and the processing from step SB120 onward is performed. The network device 200B ′ is a standby system. Therefore, the determination result of step SB120 is “No”, and the processing of step SB140 is performed. That is, all the monitoring data Bn stored in the monitoring data buffer 2522 of the network device 200B ′ are replaced with, and are received from the network device 200A ′ through the third communication I / F section 240. The monitoring data An (see FIG. 15 (B)). As a result, the control device 100A is transmitted via the network device 200A ′. The monitoring data An is also transmitted to the control device 100B via the network device 200B ′ ′ ′.

On the other hand, if some kind of trouble occurs in the IO host MA1 and the IO host MB2, as shown in FIG. 16 (A), the monitoring data A1 originally received by the network device 200A ′ is defective. The monitoring device B2 that the road device 200B should originally receive is also defective. In addition, NULL in FIG. 16 (A) means the defect of the monitoring data. In this case, as shown in FIG. 16 (A), the monitoring data A2 and A3 are transmitted from the network device 200A ′ ′ to the network device 200B ′ ′ ′ via the equalization cable 400, and from the network device 200B ′ The monitoring data B1 and B3 are transmitted to the network device 200A through the equalization cable 400.

Taking the opportunity to receive the monitoring data B1 through the third communication I / F unit 240 as an opportunity, in the equivalent reception processing 2542b2 performed in the network device 200A ′ ′, the determination result of step SB100 is “No ", The process of step SB110 is executed. As a result, as shown in FIG. 16 (B), the monitoring data A1 originally received by the network device 200A ′ was supplemented by the monitoring data B1. Similarly, in the equivalent reception processing 2542b2 performed on the network device 200B ′ ′ with the opportunity to receive the monitoring data A2 through the third communication I / F unit 240, the determination result of step SB100 is also obtained. If it is "No", the process of step SB110 is executed. As a result, as shown in FIG. 16 (B), the monitoring data B2 originally received by the network device 200B ′ was supplemented by the monitoring data A2. In this operation example, the control device 100A includes monitoring data B1, monitoring data A2, and monitoring data A3 which are equivalent monitoring data, and is controlled from the network device 200A '' ' It is transmitted; to the control device 100B, the monitoring data B1, the monitoring data A2, and the monitoring data A3 which are the equivalent monitoring data are transmitted from the network device 200B. In this operation example, the control device 100A, which is the operation system, is the control device 100A. The monitoring data is transmitted from the network device 200A ', which is equivalent to the control device. Therefore, it is possible to continue to control the target device without any problems. Control, etc.

In this way, according to this embodiment, even if some kind of failure occurs in the IO network connected to the control device of the operation system through the network device or the IO host connected to the IO network, there is no need to perform the control device. The switching of the operation system / standby system can reduce the frequency of switching between the operation system and the standby system in the redundant control system, and this effect can be achieved. Furthermore, according to this embodiment, the IO host connected to the IO network connected to the control device of the operating system via the network device fails, and the IO connected to the control device of the standby system via the network device. The IO hosts connected to the network also fail. Even in the case of such multiple failures, as long as these IO hosts are not connected to the same IO machine, they can continue to control the control of the target device, compared with the aforementioned first section. According to the first embodiment, the resistance to multiple failures can be further improved, and such an effect can be achieved. In addition, in this embodiment, the standby network device is configured to cause all monitoring data received from the IO network to pass through the equivalent cable 400 between the network devices to the operating network device. Transmission, but it is also possible to transmit only the monitoring data that is defective in the operation system. Several methods are conceivable for making the network device of the standby system detect the defect of the monitoring data in the operation system. For example, from an operating network device The equivalent cable is used to send a list of identification metadata of the monitoring data that the network device of the operating system has received to the network device of the standby system, and based on the list, the network device of the standby system detects the operation system. Defective surveillance data is sufficient. Alternatively, if the standby network device receives the monitoring data through the IO network, and after a predetermined time has passed, the data corresponding to the monitoring data is not received by the equalization cable between the network devices. The standby network device determined that the monitoring data in the operating system was defective.

In addition, when the IO auxiliary device devices S1 to S3 include the control target device, the calculation data sent from the control device 100 to the control target device, that is, the calculation result based on the monitoring data that has been equalized is displayed. The transmission control of the data may be similarly performed as long as there is no failure in the IO host connected to the control target device to the IO network 30. For example, when each of the IO auxiliary device devices S1 to S3 in FIG. 16 (B) is a control target device, the IO auxiliary device device S1 is along the control device 100A → the network device 200A ′ ′ → the equivalent value. It is only necessary to transmit the calculation data through the transmission path of the cable 400 → the network device 200B ′ ″ → the IO network 30B. Similarly, for the IO auxiliary device devices S2 and S3, the calculation data may be transmitted along the transmission path of the control device 100A → network device 200A ′ ′ → IO network 30A.

In addition, in this embodiment, the equivalent of the monitoring data is performed on the network device 200 ′ ′. Therefore, it is of course transmitted to the monitoring of the control device similarly to the first embodiment described above. Even if the amount of data is increased, the implementation of the original calculation of the control device will not cause any obstacles and will not cause the switching speed of the operation system / standby system to decrease. Low, can achieve this effect.

In the embodiment described above, although a situation in which a certain failure occurs on the IO host has been explained, when an obstacle such as a disconnection occurs in the IO network 30, or the IO network 30 and the network device 200 '' 'are connected In the event of an interruption in the communication line, such as the above, all the monitoring data that should have been received via the IO network 30 can be supplemented. In the embodiment described above, although there is only one IO network that has been doubled connected to the network device 200 ′ ′, as shown in FIG. 17, the IO network has been doubled. Departments can be connected in plural. For example, FIG. 17 illustrates a case where there are two IO networks that have been doubled and connected to the network device 200 ′ ″.

Generally, in a redundant control system, it is not ideal if there is a change in the data transmission path or the reverse transmission path from the IO slave device device to the control device 100 in the operation system. Then, the identification information indicating the transmission source that was determined to be unable to communicate in step SB100 is written to a predetermined memory area of the volatile memory section 252, and thereafter, monitoring data from the machine in which the identification information is memorized is stored in this memory area. The system always supplements or replaces the monitoring data received through the equalization cable 400, and initializes the above-mentioned memory field with the power off or reset of the device as an opportunity to make the network device 200 ′ ′ The control unit 210 may perform the above processing. According to this aspect, after the above-mentioned replenishment, etc., the repair of the IO host and the like becomes unnecessary, and the replenishment and the like will continue until the network device 200 ′ ′ ′ is powered off or reset. The data transmission path from the IO auxiliary machine device to the control system 100 of the operation system will not be switched to not perform the above-mentioned supplement. A full path can avoid the impact caused by path switching.

(E: deformation)

Although the first, second, third, and fourth embodiments of the present invention have been described above, it goes without saying that these embodiments can be modified as follows.

(1) In the first embodiment described above, it is explained that monitoring data is transmitted from the network device of the operating system to the network device of the standby system through the equalization cable 400 among the network devices 200A and 200B. And memory, the so-called push-type data communication to achieve the equivalent of surveillance data. However, the monitoring can also be implemented by request-type data communication in which the standby network device executes the processing of obtaining monitoring data from the operating network device via the equivalent cable 400 to update the monitoring data from the device. Equivalence of data. The same applies to other embodiments.

(2) The second embodiment and the third embodiment described above may be combined. Specifically, as long as each of the network device 200A ′ ′ and the network device 200B ′ ′ is made to determine whether or not data communication through the equalization cable 400 is possible, it is allowed to execute it through the equalization cable if possible. Line 400 to send monitoring data to the other network device, if it is not possible, the process of sending monitoring data to the other network device through the equalization cable 40 is sufficient. Similarly, the second embodiment and the fourth embodiment may be combined, and the second, third, and fourth embodiments may be combined.

(3) In each of the above embodiments, an example in which the present invention is applied to a gateway device that transmits monitoring data collected from an IO slave device to a control device has been described. However, the object of application of the present invention is of course It is not limited to the gateway device, and may be other types of relay devices such as routers, repeaters, and switching hubs. Furthermore, the network to be connected to the relay device of the present invention is not limited to a control network such as an IO network or a serial bus, and can also be used to mediate data communication of a general communication protocol such as TCP. General information for the Internet. The important point is that as long as the control device collects monitoring data, uses the monitoring data to perform calculations, and is connected to the network connected to the machine that outputs the monitoring data, the data received through the network will be sent to the control device The present invention is applicable to any relay device that performs transmission.

(4) It is also possible to use a single unit as the network device included in the communication system of each of the embodiments described above, that is, a relay device, that is, to manufacture and sell a single relay device. Appearance. This is because by replacing such a network device with a network device in a previous redundant control system and connecting these network devices to each other with an equalization cable between relay devices, the previous The redundant control system functions as the communication system of each embodiment described above.

(5) In each of the above embodiments, the relay processing 2542a and the equalization processing 2542b, which are significant features of the present invention (the fourth embodiment is the equivalent transmission processing 2542b1 and the equivalent reception processing 2542b2) can also be implemented by software. However, each of the relay means that executes the relay process 2542a and the equivalent means that executes the equalization process 2542b may be constituted by electronic circuits. These electronic circuits are combined to form each of the first to third embodiments described above. Network device. The same applies to the network device 200 '' 'of the fourth embodiment. Again, in the note In the embodiment, an equivalent cable is used as a communication means between the relay devices, but a wireless communication means such as a wireless LAN interface can also be used as a communication means between the relay devices. In addition, when the network device 200A and the network device 200B are installed in a single casing, the bus connecting the two devices can also be used as a communication means between the relay devices. The same applies to the means of communication between the control devices.

(6) In each of the above embodiments, it has been explained that for each of the control device 100A and the control device 100B, or whether each of the control device 100A ′ and the control device 100B ′ is an operation system or a standby system, When the monitoring data received through the network device connected to the target is used to perform calculations required for machine control, that is, the control system of the hot standby mode, the present invention is applicable. However, the applicable object of the present invention is not limited to the control system of the hot standby mode, but can also be applied to the control system of the warm standby mode. The control system of the warm standby mode is the same as the control system of the hot standby mode in which one of the control devices that has been doubled will become the operating system and perform the calculation above, and the other will become the standby system to prevent the failure of the operating system. However, the above-mentioned calculation is not performed in the control device of the standby system, which is different. Furthermore, in the first to third embodiments described above, even in a standby network device, the monitoring data received by the first communication I / F unit 220 is written to the monitoring data buffer 2522. Processing (Fig. 4 (B): each processing of S100 and S110), but this processing may be omitted in the network device of the standby system. This is because the monitoring data written into the monitoring data buffer 2522 through the processing of S100 and S110 in FIG. 4 (B) is equivalent to the processing of 2542b. The process of step SA120 is completely overwritten.

Claims (11)

A control system is a control system that collects monitoring data from one or a plurality of machines connected to the first and second networks and performs control based on the monitoring data, and is characterized by comprising: first and second control devices , One of which becomes the operation system and performs the preamble control, and the other becomes the standby system; and the first relay device is connected to the preamble first control device and preamble first network; and the second relay device, Is connected to the second control device and the second network; the communication means between the relay devices is used to mediate the communication between the first relay device and the second relay device; and the communication device between the control devices, It is used to mediate the communication between the first control device and the second control device; the first and second relay devices are equipped with: judging means to determine whether the communication through the communication means between the relay devices can be carried out; Each of the first and second relay devices in the preamble is to transmit the monitoring data received from the preamble 1 or a plurality of devices to the control device of the connection target, and when it is judged as communicable by the preface judgment means , The equivalent of the monitoring data is communicated through the communication means between the relay devices in the preamble, and on the other hand, when it is determined that the communication cannot be communicated by the preface judgment means, the communication means between the devices is controlled through the preface Communication to equivalence of monitoring data; the first control device and the second control device in the predecessor, which are the operating systems, use the monitoring data received from the relay device connected to the predecessor control . The control system as described in claim 1, wherein one of the first and second relay devices described above performs a process of transmitting the monitoring data received from the network of the connection target to the relay device of the other party , As a process to equalize the monitoring data; the other one of the first and second relay devices described above is executed, and the monitoring data received from the network connected to the target is used as corresponding to the monitoring data The process of replacing the monitoring data received from the relay device on the previous side is used as the process of equalizing the monitoring data. The control system as described in claim 1 or claim 2, wherein the first and second control devices in the preamble determine whether communication through the communication means between the preamble control devices is possible, and if it is possible, by indicating from The status data of whether the device is faulty is sent through the communication means between the pre-control devices to monitor whether the other party is faulty. If it is impossible, the pre-status data is sent through the communication means between the relay devices to monitor the other party. Are there any faults? The control system as described in claim 1, wherein the first and second relay devices in the foregoing are to receive the monitoring data sent from each of the plurality of machines; for each of the plurality of previous machines , It is specified in advance whether it is to be performed on the relay device side or on the control device side to perform equivalence of the monitoring data sent from the device; Equalization of the monitoring data received by the machine that is to be equalized on the relay device side; each of the first and second control devices described above is performed through the relay device connected to the target Among the monitoring data, the equalization of the monitoring data sent from the device that is to be equalized on the control device side is specified. The control system as recited in claim 1, wherein each of the first and second relay devices described above has: a first processing means for transmitting the monitoring data received from the network connected to the target To the relay device of the other party; and the second processing means is to determine whether it is possible to communicate with the machine of the source of the monitoring data received from the relay device of the other party, and the original should be judged as impossible The monitoring data received by the communicating machine is supplemented by the monitoring data received from the relay device of the other party. The control system as recited in claim 5, wherein the second processing means in the preceding section stores the identification information indicating the machine determined to be unavailable for communication in the memory device, and targets the machine whose identification information has been stored in the memory device It is supplemented or replaced by the monitoring data received from the relay device of the other party. On the other hand, the memory contents of the previous memory device are initialized with the opportunity of power off or reset from the device. The control system according to claim 1, wherein the first and second relay devices described above are provided with: load measurement means for measuring the processing load applied to the control device of the connection target; the first and second notes For each of the relay devices, when the processing load measured by the prescriptive load measuring means is above a predetermined threshold value and is determined to be communicable by the prescriptive determination means, the communication is performed through the communication means between the prescriptive relay devices. The equivalence of monitoring data is carried out. In other cases, the equivalence of monitoring data is carried out by means of communication through the communication means between the control devices. The control system according to claim 1, wherein the first and second relay devices described above are provided with: load measurement means for measuring the processing load applied to the control device of the connection target; The higher the processing load of the 1st and 2nd control devices, the more monitoring data is equalized on the relay device side. Is the monitoring data equalized on the relay device side or on the control device side? Modal is a plurality of modes that are specified in accordance with the processing load in the previous note; each of the first and second relay devices in the previous note is divided into modalities corresponding to the processing load measured by the load measurement method in the previous note It is specified that the equalization of the monitoring data to be equalized on the relay device side; each of the first and second control devices described in the foregoing is to be divided into modes corresponding to the processing load of the self-device It is stipulated that the monitoring data to be equalized is to be equalized on the control device side. The control system as described in claim 1, wherein either one of the first and second relay devices described above is connected to the third network; the relay device connected to the third network described above is connected from the The machine connected to the third network described above collects monitoring data, and transmits the collected monitoring data to the control device connected from the device and also to the relay device of the other party. The control system according to claim 1, wherein the relay device pair formed by the first relay device and the second relay device communicating through the communication means between the relay devices has plural pairs. A relay device is connected to one of the first and second control devices. The first and second control devices are connected to the communication means between the control devices, and one side becomes the operation system to control and the other side becomes The standby system, and the preamble relay device is connected to the first network connected to the one or more devices that send monitoring data, and transmits the monitoring data sent from the preamble 1 or the multiple devices to the control of the connection target The device is characterized by having a communication interface, which is connected to the inter-relay communication means, the inter-relay inter-relay communication means is the communication between the intermediary and other relay devices, and the pre-recorded other relay devices are connected to the preamble 1 or the second network connected to a plurality of machines and the other of the first and second control devices; and the control unit, which executes: relay processing, will be from the previous 1 or 1 through the first network The monitoring data received by a plurality of machines is transmitted to the control device of the connection target; and the determination process is to determine whether the communication through the communication means between the relay devices in the previous note can be performed; and the equalization process is determined in the previous decision process as When communication is possible, the communication necessary for equalizing the monitoring data is performed through the communication means between the relay devices, and on the other hand, when it is determined that communication is impossible, the communication is performed through the communication means between the control devices.