Edge module, control system, remote control system, controller and communication method

Abstract

To provide an edge module capable of performing fixed cycle processing, a control system, a remote control system, a controller and a communication method.SOLUTION: An edge module comprises: a data generation section which generates first data including serial numbers; a transmission section which applies a first time to the first data and transmits the first data to a controller; a reception section for receiving second data, which are generated by the controller on the basis of the first data, including the serial numbers and the first time, and acquiring a second time which is a time when pieces of second data are received; and an abnormality detection section for determining whether communication with the controller is normally performed on the basis of at least one of the serial numbers included in the second data and a differential between the first time, which is included in the second data, and the second time.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to an edge module, a control system, a remote control system, a controller, and a communication method. [Background technology]

[0002] Control systems for industrial plants, etc. are constructed by connecting edge systems that include the equipment to be controlled (target equipment) and sensors that measure values ​​related to control, and a controller for controlling the target equipment based on the output from the sensors.

[0003] When a controller and an edge system are connected via a local LAN, communication between them is fast and simultaneity is guaranteed. In addition, when the controller is a physical machine, the generation of control data for the edge system and the output to the edge system can be completed within one scan cycle (one calculation cycle). Therefore, it is possible to perform fixed-cycle processing.

[0004] In contrast, transferring the controller to the cloud offers the advantages of reducing the initial implementation and update costs of the control system, and improving the flexibility and operability of the control system configuration. However, when the controller is transferred to the cloud space, simultaneity cannot be guaranteed because the edge system and the controller are connected via the Internet, which has a large network latency. In addition, since resources (computing resources) cannot be secured in the cloud space as much as physical machines connected by a local LAN, it may not be possible to complete the generation of control data for the edge system and the output to the edge system within one scan. This causes the time required for each process to vary, making it impossible to perform fixed-cycle processing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2021-525044 [Patent Document 2] Patent Publication No. 2021-121065 [Patent Document 3] JP 2018-152675 A Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE DISCLOSURE The embodiments of the present invention provide an edge module, a control system, a remote control system, a controller, and a communication method that enable periodic processing. [Means for solving the problem]

[0007] The edge module of this embodiment includes a data generation unit that generates first data including a serial number, a transmission unit that assigns a first time to the first data and transmits the first data to a controller, a receiving unit that receives second data generated by the controller based on the first data, the second data including the serial number and the first time, and obtains a second time that is the time when the second data was received, and an abnormality detection unit that determines whether communication with the controller has been performed normally based on at least one of the serial number included in the second data and the difference between the first time and the second time included in the second data. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a block diagram showing a remote control service according to the first embodiment. [Diagram 2] 1 is a block diagram showing a remote control system according to a first embodiment. [Diagram 3] A diagram explaining the data format. [Figure 4] FIG. 2 is a sequence diagram illustrating processing of the remote control system according to the first embodiment. [Diagram 5] FIG. 11 is a sequence diagram illustrating another process of the remote control system according to the first embodiment. [Figure 6]5A and 5B are diagrams for explaining a process performed by an anomaly detection unit. [Figure 7] FIG. 11 is a block diagram showing a remote control system according to a modified example of the first embodiment. [Figure 8] FIG. 11 is a sequence diagram illustrating a process of a remote control system according to a modified example of the first embodiment. [Figure 9] FIG. 11 is a block diagram showing a remote control system according to a second embodiment. [Figure 10] FIG. 11 is a sequence diagram illustrating the processing of the remote control system according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] (First embodiment) Fig. 1 is a block diagram showing an example of a remote control service 10 according to the first embodiment. The remote control service 10 includes a plurality of control systems 2_1 to 2_N, a plurality of controller virtual machines (controllers) 3_1 to 3_M, and a communication network 4. Hereinafter, one of the plurality of control systems 2_1 to 2_N will be simply referred to as a control system 2, and one of the plurality of controllers 3_1 to 3_M will be simply referred to as a controller 3. The remote control service 10 is a service for controlling a plurality of devices (target devices 21) included in an industrial plant or the like.

[0011] The control system 2 includes a target device 21 to be controlled, a sensor (measurement device) 22, an I / O device 23, and an edge module 24. The control system 2 is an edge-side control system that transmits measurement data acquired by the sensor 22 to a controller 3 and actually controls the target device 21 based on control data received from the controller 3. The measurement data is an example of first data transmitted from the edge module 24 to the controller 3. The control data is an example of second data transmitted from the controller 3 to the edge module 24.

[0012] The target equipment 21 is equipment that constitutes an industrial plant, and is, for example, a valve, a pump, a heat exchanger, a mixer, and the like.

[0013] The sensor 22 measures a value related to the control of the target device 21 and outputs it as a measurement signal (analog signal). The sensor 22 may monitor the operation of the target device 21 itself, or may monitor the operation of another device related to the target device 21. The sensor 22 may be built into the target device 21, or may be located at a location physically separated from the target device 21. One control system 2 may include multiple sensors 22. When the target device 21 is a pump, the sensor 22 is, for example, a flow meter.

[0014] The I / O device 23 is a device for performing input and output with the target device 21 and the sensor 22 that configure the plant. The I / O device 23, for example, collects a measurement signal measured by the sensor 22 from the sensor 22 and outputs it to the edge module 24. In addition, the I / O device 23 outputs a control signal received from the edge module 24 to the target device 21 to control the target device 21.

[0015] The edge module 24 is an electronic device for generating measurement data based on measurement signals from the sensor 22 and generating control signals based on control data from the controller 3. The edge module 24 also communicates with the controller 3.

[0016] The controller 3 receives measurement data from the control system 2, and generates control data for controlling the target device 21 based on the measurement data. The controller 3 also transmits the control data to the control system 2. In this embodiment, the controller 3 is a virtual machine provided in a cloud space (cloud server), but the controller 3 may also be a physical machine.

[0017] The communication network 4 connects between the multiple control systems 2_1 to 2_N and the controllers 3_1 to 3_M. In this embodiment, the communication network 4 is the Internet, but this does not exclude a configuration in which other types of communication networks are adopted.

[0018] Each of the multiple control systems 2_1 to 2_N exchanges data with the multiple controllers 3_1 to 3_M. Here, a set of one control system 2 and one controller 3 that exchanges data with the control system 2 is referred to as a remote control system 1. In other words, the remote control service 10 includes multiple remote control systems 1.

[0019] Fig. 2 is a block diagram showing an example of a remote control system 1 according to the first embodiment. Note that Fig. 2 does not show that a specific control system 2 and a specific controller 3 correspond one-to-one. In other words, the controller 3 corresponding to a certain control system 2 is not fixed. For example, a target device 21 provided in a control system 2_3 different from the control system 2_2 may be controlled based on measurement data acquired from a sensor 22 provided in the control system 2_2. In such a case, one control system 2 may not include the target device 21 or the sensor 22.

[0020] The remote control system 1 is a system in which a controller 3 generates control data for controlling a target device 21 based on a measurement signal measured by a sensor 22, and controls the target device 21 based on the control data.

[0021] The edge module 24 includes a measurement data generating unit 241 , a transmitting unit 242 , a receiving unit 243 , an abnormality detecting unit 244 , and a control signal generating unit 245 .

[0022] The measurement data generating unit 241 acquires a measurement signal from the I / O device 23 and generates measurement data. For example, the measurement data generating unit 241 converts the measurement signal, which is an analog signal, into a digital signal to generate the measurement data. Alternatively, the measurement data generating unit 241 may generate the measurement data based on a plurality of measurement signals obtained from a plurality of sensors 22.

[0023] The transmitting unit 242 assigns the time when the measurement data is transmitted as a first time to the measurement data, and transmits the measurement data to the controller 3 via the communication network 4. The receiving unit 243 receives the control data transmitted from the controller 3 via the communication network 4. At this time, the receiving unit 243 acquires the time at which the control data is received as the second time.

[0024] The anomaly detection unit 244 judges whether or not communication between the edge module 24 and the controller 3 has been performed normally (whether or not an anomaly has occurred) based on the received control data. In other words, it judges whether or not the processing by the controller 3 has been performed normally without excessive delay, and whether or not both the transmission of measurement data and the reception of control data corresponding to the measurement data have been successful without excessive delay. In addition, the anomaly detection unit 244 judges whether or not an emergency has occurred depending on the number of times an anomaly has been detected during operation of the remote control system 1. The number of times may be the average number of times per certain period of time.

[0025] The control signal generating unit 245 generates a control signal based on the received control data. Furthermore, when the abnormality detecting unit 244 determines that an emergency has occurred, the control signal generating unit 245 may generate a control signal for an emergency. The control signal for an emergency includes, for example, a command to make an emergency stop of the target device 21 or a command to activate a safety device.

[0026] At least some of the elements 21 to 23 and the elements 241 to 245 may be configured by a circuit or a processor, such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). Alternatively, some or all of these elements may be executed by a CPU that executes a program.

[0027] The controller 3 includes a receiving function unit F31, a calculation function unit F32, a control data generating function unit F33, and a transmitting function unit F34. In other words, the controller 3 functions as various functional units on the cloud.

[0028] The receiving function unit F31 receives the measurement data transmitted from the edge module 24 via the communication network 4. The transmission function unit F34 transmits the control data via the communication network 4.

[0029] The arithmetic function unit F32 processes the measurement data received by the receiving function unit F31. For example, the arithmetic function unit F32 analyzes the measurement data and determines whether the target device 21 is operating normally, whether the measurement data includes an abnormal value, and the like.

[0030] Based on the result of the processing by the calculation function unit F32, the control data generation function unit F33 generates control data for controlling the target device 21. The control data generation function unit F33 generates one piece of control data based on one piece of measurement data (for example, one packet).

[0031] The controller 3 executes various processes including the processes of the functional units F31 to F34 by executing an arbitrary control program. The control program is executed at a predetermined scan period. The scan period includes a refresh, a control program execution (calculation) time, an END processing time, etc.

[0032] The cloud server provided with the controller 3 of this embodiment is realized by a hardware configuration including a control device such as an MPU, a storage device, etc. The storage device is realized by a memory device such as a ROM (Read Only Memory) or a RAM (Random Access Memory), an external storage device such as a HDD or a CD drive device, or both of these. Furthermore, it is not excluded that the cloud server is provided with a display device such as a display device, and an input device such as a keyboard or a mouse.

[0033] The control program executed by the controller 3 of this embodiment is provided in the form of an installable or executable file recorded on a computer-readable disk-shaped recording medium such as a DVD (Digital Versatile Disk), a USB memory, an SSD (Solid State Disk), or other semiconductor storage device.

[0034] The control program executed by the controller 3 of the present embodiment may be stored in a computer connected to a network such as the Internet and provided by being downloaded via the network. The control program executed by the controller 3 of the present embodiment may be provided by being pre-installed in a ROM or the like.

[0035] In this embodiment, when the controller 3 receives the measurement data, it performs calculation processing within the next (immediately following) scan cycle and generates control data. Then, the controller 3 transmits the control data to the edge module 24 within the scan cycle after the next. In other words, the controller 3 generates the control data and transmits the control data to the edge module 24 within different scan cycles. As a result, if no excessive delay occurs within the controller 3, the time taken from generating to transmitting the control data can be kept constant (one scan cycle), and variations in processing time can be suppressed.

[0036] 3 is a diagram for explaining the formats of the measurement data and the control data. The measurement data and the control data are generated, for example, in the form of a packet. As shown in FIG. 3, both the measurement data and the control data include a sequence number (first sequence number), a first time, and a payload (data 1, data 2, ...).

[0037] The serial number is a number that the measurement data generating unit 241 assigns to the measurement data, and is used for abnormality detection by the abnormality detecting unit 244. The serial number "0x987F" is assigned to the data shown in Fig. 3. The serial number may be, for example, a counter value of a PLC (Programmable Logic Controller) included in the measurement data generating unit.

[0038] The first time is the time when the transmission unit 242 transmits the measurement data. The first time may be, for example, the time when the measurement data generation unit 241 generates the measurement data. In the example shown in Fig. 3, data with a serial number "0x987F" is transmitted at a time "0x07836287f32a".

[0039] The payload is the main body of the measurement data or control data. For example, the payload of the control data includes a command to stop the target device 21.

[0040] (Example 1) Here, a description will be given of an overall picture of the processing performed by the remote control system 1. Fig. 4 is a sequence diagram of the remote control system 1 in normal times (when no emergency occurs). An example of the operation of the remote control system 1 will be described below with reference to Fig. 4.

[0041] First, the I / O device 23 outputs a measurement signal obtained by the sensor 22 to the edge module 24 (step S101).

[0042] Next, the measurement data generating unit 241 generates measurement data based on the input measurement signal. At this time, the measurement data generating unit 241 assigns a first serial number to the generated measurement data (step S102).

[0043] Next, the transmitting unit 242 transmits the measurement data to the controller 3. At this time, the transmission time is added to the measurement data as the first time and then transmitted (step S103).

[0044] Next, the controller 3 functions as the receiving function unit F31 and receives the measurement data (step S104). Next, the controller 3 functions as the calculation function unit F32 and processes the measurement data (step S105). Here, since the controller 3 processes the measurement data at every predetermined calculation cycle, a waiting time of up to one scan cycle occurs from the completion of step S104 until the start of step S105.

[0045] Next, the controller 3 functions as the control data generation function unit F33, and generates control data for controlling the target device 21 based on the processing result of step S105 (step S106).

[0046] Next, the controller 3 functions as the control data generation function unit F33 and assigns a serial number and a first time to the generated control data (step S107). The serial number and the first time assigned at this time are the same as those included in the measurement data corresponding to the control data.

[0047] Next, the controller 3 functions as the transmission function unit F34 and transmits the control data to the edge module 24 (step S108). Step S108 is executed within a scan period different from the scan period in which step S107 was executed.

[0048] Next, the receiving unit 243 receives the control data and acquires the time (second time) at which the control data is received (step S109).

[0049] Next, the abnormality detection unit 244 determines whether or not communication with the controller 3 has been performed normally based on the received control data (step S110). If no abnormality is detected (step S111: No), the process proceeds to step S112.

[0050] If an abnormality is detected (step S110: Yes), the abnormality detection unit 244 determines whether or not an emergency occurs (step S111). If it is determined that an emergency does not occur, the process proceeds to step S112 (step S111: No). If it is determined that an emergency occurs, the process proceeds to step A.

[0051] Next, the control signal generating unit 245 generates a control signal based on the received control data, and transmits the control signal to the I / O device 23 (step S112).

[0052] Next, the I / O device 23 receives the control signal and controls the target device 21 based on the control signal (step S113).

[0053] (Example 2) Next, the process performed by the remote control system 1 when an emergency occurs (step A and after) will be described. Fig. 5 is a sequence diagram of the remote control system 1 when an emergency occurs. Below, an example of the operation of the remote control system 1 will be described with reference to Fig. 5. The operation before step A is omitted because it is the same as Fig. 4.

[0054] First, when the abnormality detection unit 244 determines that an emergency has occurred, the process proceeds to step S201 (step A).

[0055] Next, the control signal generating unit 245 generates a control signal for an emergency (emergency control signal) and transmits it to the I / O device 23 (step S201). The emergency control signal includes, for example, a command to stop the target device 21 and a command to activate a safety device. The I / O device 23 then controls the target device 21 based on the received emergency control signal (step S202).

[0056] Next, the edge module 24 generates an emergency notification to notify the controller 3 that an emergency has occurred, and transmits the emergency notification to the controller 3 (step S203).

[0057] Next, the controller 3 receives and processes the emergency notification (step S204). After that, the controller 3 may notify the user that an emergency state has occurred, or may attempt to restore the control system 2.

[0058] As described above, the remote control system 1 communicates between the edge module 24 and the controller 3 to control the target device 21. In addition, by determining whether an emergency occurs on the edge side, it is possible to quickly respond to the emergency.

[0059] Next, the process performed by the abnormality detection unit 244 in steps S110 and S111 will be described with reference to Fig. 6. Fig. 6 is a diagram for explaining the process performed by the abnormality detection unit 244.

[0060] The abnormality detection unit 244 judges whether or not communication with the controller 3 has been performed normally based on at least one of the serial number included in the control data and the difference between the first time and the second time. More specifically, the abnormality detection unit 244 judges an abnormality when at least one of the following is satisfied: a missing number occurs in the serial number included in the control data; and the difference between the first time and the second time is equal to or greater than a predetermined delay time. Furthermore, when an abnormality is detected (judged) a predetermined number of times (one or more times), the abnormality detection unit 244 judges an emergency. When an emergency is judged when an abnormality is detected once, a quick response to the abnormality is possible. When an emergency is judged when an abnormality is detected multiple times, accidental abnormalities can be excluded.

[0061] The difference between the first time and the second time corresponds to the time it takes from the start of step S103 to the completion of step S109 (see FIG. 4). Here, the time taken from the start of measurement data processing to the start of control data transmission (start of steps S105 to start of S108) is one scan period, unless an excessive delay occurs within the controller 3. Furthermore, the waiting time from the completion of measurement data reception to the start of measurement data processing (from completion of step S104 to start of S105) is one scan cycle at maximum. It is assumed that the total time required for communication between the edge module 24 and the controller 3 (from the start of step S103 to the completion of step S104, and from the start of step S108 to the completion of step S109) is less than one scan period if the communication between them is normal. Considering these factors, if communication between the edge module 24 and the controller 3 is performed normally, the difference between the first time and the second time is expected to be within three scan periods.

[0062] In the example shown in Fig. 6, one scan period is 100 ms. Therefore, the predetermined delay time is, for example, 300 ms. The control data with the serial number 2 (hereinafter referred to as control data 2) is determined to be abnormal by the abnormality detection unit 244 because the difference between the first time and the second time is 302.25 ms. However, at the time of determination of the control data 2, the cumulative number of abnormality detections is 1, so it is not determined to be an emergency. The control data 5 with the serial number 5 is determined to be abnormal because the serial number of the control data immediately before it is 3. Furthermore, at this point in time, the cumulative number of abnormality detections has reached 2, so it is determined to be an emergency by the abnormality detection unit 244.

[0063] As described above, the first time and the first serial number are assigned to the measurement data, and the same first time and first serial number are assigned to the control data based on the measurement data. This makes it possible to detect an abnormality when communication between the edge module 24 and the controller 3 is not performed normally by checking the difference between the first time and the second time or the first serial number when the control data is received. This also makes it possible to perform periodic processing within the remote control system 1.

[0064] In addition, in order to check the difference between the first time and the second time, the first time may be stored on the edge module 24 side, and when control data is received, the difference between the stored first time and the second time included in the control data may be checked.

[0065] (Modification) In the above description, the abnormality detection unit 244 included in the edge module 24 judges whether or not an emergency state exists, but the controller 3 may judge whether or not an emergency state exists. By having the controller 3 judge whether or not an emergency state exists, a more comprehensive judgment that takes into account the overall situation of the remote control service 10 can be made.

[0066] Fig. 7 is a block diagram showing a remote control system 1 according to a modified example of the first embodiment. Elements having the same names or functions as those in Fig. 2 of the first embodiment described above are given the same reference numerals. Hereinafter, explanations will be omitted except for changes or additions.

[0067] The edge module 24 includes an abnormality notification generation unit 246. When the abnormality detection unit 244 detects an abnormality, the abnormality notification generation unit 246 generates an abnormality notification to notify the controller 3 of the abnormality. The generated abnormality notification is transmitted to the controller 3 by the transmission unit 242, received by the reception function unit F31, and processed by the calculation function unit F32.

[0068] The controller 3 includes a state determination function unit F35. The state determination function unit F35 determines whether or not an emergency has occurred based on the number of abnormality notifications received and processed (number of times abnormality notifications have been received). The state determination function unit F35 determines that an emergency has occurred when the number of times abnormality notifications have been received reaches a predetermined number (one or more times). When the state determination function unit F35 determines that an emergency has occurred, the control data generation function unit F33 generates control data for an emergency. The control data generation function unit F33 may generate control data for an emergency after confirming the status of other remote control systems 1 from information from other controllers 3. This makes it possible to prevent, for example, a situation in which stopping a certain target device 21 has an adverse effect on other target devices 21.

[0069] Fig. 8 is a sequence diagram of the remote control system 1 according to this modification. Hereinafter, an operation example of the remote control system 1 according to this modification will be described with reference to Fig. 8. Operations before step S110: No are omitted because they are the same as those in Fig. 4.

[0070] First, the abnormality detection unit 244 detects that an abnormality has occurred (step S111: Yes).

[0071] Next, the abnormality notification generating unit 246 generates an abnormality notification for notifying the controller 3 that an abnormality has occurred, and transmits the abnormality notification to the controller 3 (step S301).

[0072] Next, the controller 3 functions as the receiving function unit F31 to receive the abnormality notification, and then the controller 3 functions as the arithmetic function unit F32 to process the abnormality notification (step S302).

[0073] Next, the controller 3 functions as the state determination function unit F35, and determines whether or not an emergency has occurred based on the number of times that the abnormality notification has been received (step S303: Yes).

[0074] Next, the controller 3 functions as a control data generation function unit F33 and generates emergency control data to perform control according to the emergency. Then, the controller 3 functions as a transmission function unit F34 and transmits the emergency control data to the edge module 24 (step S304). The emergency control data includes, for example, a command to stop the target device 21 and a command to activate a safety device.

[0075] Next, the receiving unit 243 receives the emergency control data (step S305). Then, the control signal generating unit 245 generates an emergency control signal based on the emergency control data and transmits the emergency control signal to the I / O device 23 (step S306).

[0076] Next, the I / O device 23 controls the target device 21 (step S307).

[0077] Second embodiment In the first embodiment, a method has been described in which the edge module 24 performs periodic processing between the controller 3 and the edge module 24. In the second embodiment, a method will be described in which, from the perspective of the controller 3, it is confirmed that communication between the controller 3 and the edge module 24 has been performed normally.

[0078] Fig. 9 is a block diagram showing a remote control system 1A according to the second embodiment. Elements having the same names or functions as those in Fig. 2 of the first embodiment described above are given the same reference numerals. Hereinafter, explanations will be omitted except for changes or additions.

[0079] When generating control data, the control data generation function unit F33 assigns a second serial number to the control data. The second serial number is unique to the controller 3 and is different from the first serial number that the measurement data generation unit 241 assigns to the measurement data.

[0080] The transmission function unit F34 assigns the time when the control data is transmitted to the control data as the third time. Alternatively, the time when the control data generation function unit F33 generates the control data may be set as the third time.

[0081] The edge module 24 includes a response data generating unit 247. When the receiving unit 243 receives the control data, the response data generating unit 247 generates response data. The response data generating unit 247 assigns a second serial number and a third time to the response data. The response data is transmitted to the controller 3 by the transmitting unit 242. The format of the response data is similar to the example of the measurement data or control data shown in FIG. 3. The response data is an example of third data transmitted from the edge module 24 to the controller 3.

[0082] The receiving function unit F31 receives the response data transmitted from the edge module 24 via the communication network 4. At this time, the receiving function unit F31 acquires the time at which the response data is received as the fourth time.

[0083] The controller 3 includes an abnormality detection function unit F36. The abnormality detection function unit F36 determines whether or not communication between the controller 3 and the edge module 24 has been performed normally (whether or not an abnormality has occurred) based on the received response data. In other words, it determines whether or not both the transmission of control data and the reception of response data corresponding to the control data have been successful without excessive delay.

[0084] The anomaly detection function unit F36 determines whether communication with the edge module 24 has been performed normally based on at least one of the serial number included in the response data and the difference between the third time and the fourth time. More specifically, the anomaly detection function unit F36 determines that an anomaly has occurred when at least one of the following conditions is met: a missing number occurs in the serial number included in the response data; and the difference between the third time and the fourth time is equal to or greater than a predetermined delay time. Furthermore, when an anomaly is detected a predetermined number of times (one or more times), the anomaly detection function unit F36 determines that an emergency has occurred.

[0085] Fig. 10 is a sequence diagram of the remote control system 1A according to this embodiment. Hereinafter, an example of the operation of the remote control system 1A according to this embodiment will be described with reference to Fig. 10. Operations before step S105 are omitted because they are the same as those in Fig. 4. Steps having the same functions as those in the sequence diagram described above are given the same reference numerals, and descriptions thereof are omitted or simplified as appropriate.

[0086] First, the controller 3 functions as the control data generation function unit F33 and generates control data for controlling the target device 21 (step S106). Then, the controller 3 functions as the control data generation function unit F33 and assigns a second serial number to the control data (step S401).

[0087] Next, the controller 3 functions as the transmission function unit F34 and transmits the control data to the edge module 24. At this time, the transmission time is added to the control data as the third time and transmitted (S402). Then, the receiving unit 243 receives the control data (step S109).

[0088] Next, the response data generating unit 247 generates response data in response to receiving the control data (step S402). Then, the response data generating unit 247 assigns a second serial number and a third time to the response data (step S403). Then, the transmitting unit 242 transmits the response data to the controller 3 (step S404).

[0089] Next, the controller 3 functions as the receiving function unit F31 and receives the response data. At this time, the receiving time is acquired as the fourth time. Then, the controller 3 functions as the arithmetic function unit F32 and processes the response data (step S405).

[0090] Next, the controller 3 functions as the abnormality detection function unit F36, and determines whether the edge module 24 has normally received the control data. If an abnormality is detected, the process proceeds to step S303 (step S406: Yes). The subsequent processing is omitted since it is the same as that in FIG. 8.

[0091] As described above, according to the second embodiment, it is possible to confirm, from the controller 3 side, that communication between the controller 3 and the edge module 24 has been performed normally.

[0092] The present invention is not limited to the above-described embodiments as they are, and the components can be modified and embodied in the implementation stage without departing from the gist of the invention. Various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, a configuration in which some components are deleted from all the components shown in each embodiment can also be considered. Furthermore, the components described in different embodiments can be appropriately combined.

[0093] This embodiment can also be configured as follows. [Item 1] a data generating unit that generates first data including a serial number; a transmission unit that adds a first time to the first data and transmits the first data to a controller; a receiving unit that receives second data generated by the controller based on the first data, the second data including the serial number and the first time, and obtains a second time that is a time when the second data is received; an abnormality detection unit that determines whether communication with the controller has been performed normally based on at least one of the serial number included in the second data and a difference between the first time and the second time included in the second data; and An edge module comprising: [Item 2] The abnormality detection unit determines that communication with the controller is not normal when at least one of the following conditions is satisfied: when a missing number is present in the serial number included in the second data; and when a difference between the first time and the second time is equal to or greater than a predetermined delay time. Item 1. The edge module according to item 1. [Item 3] The abnormality detection unit determines that an emergency has occurred when it has determined that communication with the controller is not performed normally a predetermined number of times. 3. The edge module according to item 1 or 2. [Item 4] The transmission unit transmits the first data to the controller via the Internet; The receiving unit receives the second data from the controller via the Internet. Item 4. The edge module according to any one of items 1 to 3. [Item 5] The controller is a virtual machine hosted on the cloud. 5. The edge module according to item 4. [Item 6] The edge module according to item 1, A target device to be controlled; A measuring device that measures a value related to the control of the target device; Equipped with the first data is data measured by the measuring device, The second data is data for controlling the target device. Control system. [Item 7] A control system according to item 6, The controller; Equipped with The transmission unit transmits the first data to the controller via the Internet; The receiving unit receives the second data from the controller via the Internet, The controller is a virtual machine provided on a cloud, The controller: A receiving function unit that receives the first data; a data generation function unit that generates the second data based on the first data; A transmission function unit that transmits the second data to the edge module. Remote control system. [Item 8] The generation of the second data by the data generation function unit and the transmission of the second data to the edge module by the transmission function unit are executed within different scan periods. 8. The remote control system according to item 7. [Item 9] The edge module further includes an abnormality notification generating unit that generates an abnormality notification when the abnormality detection unit determines that communication with the controller is not performed normally, The transmission unit transmits the abnormality notification to the controller, The receiving function unit receives the abnormality notification, The controller further includes a state determination function unit that determines that an emergency has occurred when the number of times the abnormality notification has been received reaches a predetermined number. 9. A remote control system according to item 7 or 8. [Item 10] a data generating function unit that generates second data including a serial number; a transmission function unit that adds a third time to the second data and transmits the second data to an edge module; a receiving function unit that receives third data generated by the edge module based on the second data, the third data including the serial number and the third time, and obtains a fourth time that is the time when the third data is received; an anomaly detection function unit that determines whether communication with the edge module has been performed normally based on at least one of the serial number included in the third data and a difference between the third time and the fourth time included in the third data; A controller comprising: [Item 11] The abnormality detection function unit determines that communication with the edge module is not normal when at least one of the following conditions is satisfied: when there is a missing part in the serial number included in the third data, and when a difference between the third time and the fourth time is equal to or greater than a predetermined delay time. Item 11. The controller according to item 10. [Item 12] It is a virtual machine installed on the cloud. Item 12. A controller according to item 10 or 11. [Item 13] generating first data including a serial number; adding a first time to the first data and transmitting the first data to a controller; receiving second data generated by the controller based on the first data, the second data including the serial number and the first time, and acquiring a second time which is a time when the second data is received; determining whether communication with the controller has been performed normally based on at least one of the serial number included in the second data and a difference between the first time and the second time included in the second data; A communication method comprising: [Item 14] generating second data including a serial number; adding a third time to the second data and transmitting the second data to an edge module; receiving third data generated by the edge module based on the second data, the third data including the serial number and the third time, and obtaining a fourth time which is the time when the third data is received; determining whether communication with the edge module has been performed normally based on at least one of the serial number included in the third data and a difference between the third time and the fourth time included in the third data; A communication method comprising: [Explanation of symbols]

[0094] 1. 1A remote control system 2. 2_1~2_N Control System 3, 3_1~3_M Controller 4. Communication Network 21 Target Devices 22 Sensors (measuring instruments) 23 I / O equipment 24 Edge Module 241 Measurement Data Generation Unit 242 Transmitter 243 Receiving section 244 Anomaly Detection Unit 245 Control signal generator 246 Abnormal notification generation unit 247 Response Data Generation Unit F31 Receiving function part F32 Calculation Function Unit F33 Control data generation function F34 Transmission function unit F34 Control data generation function F35 Status Judgment Function F36 Abnormality detection function part

Claims

1. A data generation unit that generates first data including a serial number; A transmission unit that assigns a first time to the first data and transmits the first data to a controller; A reception unit that receives second data including the serial number and the first time generated by the controller based on the first data, and acquires a second time that is the time when the second data is received; An abnormality detection unit that determines whether communication with the controller has been performed normally based on at least one of the serial number included in the second data and the difference between the first time included in the second data and the second time; An edge module comprising the above.

2. When the abnormality detection unit satisfies at least one of the cases where there is a missing serial number in the second data and where the difference between the first time and the second time is equal to or greater than a predetermined delay time, the abnormality detection unit determines that communication with the controller has not been performed normally. The edge module according to Claim 1.

3. When the abnormality detection unit determines a predetermined number of times that communication with the controller has not been performed normally, the abnormality detection unit determines an emergency. The edge module according to Claim 1.

4. The transmission unit transmits the first data to the controller via the Internet. The reception unit receives the second data from the controller via the Internet. The edge module according to Claim 1.

5. The controller is a virtual machine provided on the cloud. The edge module according to Claim 4.

6. The edge module according to Claim 1; A target device to be controlled; A measuring device that measures a value related to the control of the target device; Comprising the above; The first data is data measured by the measuring device; The second data is data for controlling the target device. A control system.

7. The control system according to Claim 6; The controller; Comprising the above; The transmission unit transmits the first data to the controller via the Internet. The reception unit receives the second data from the controller via the Internet. The controller is a virtual machine provided on the cloud. The controller; A reception functional unit that receives the first data; A data generation functional unit that generates the second data based on the first data; A transmitter function unit that transmits the second data to the edge module. Remote control system.

8. The generation of the second data by the data generation function unit and the transmission of the second data to the edge module by the transmitter function unit are executed within different scan cycles. The remote control system according to claim 7.

9. When the edge module determines that the communication between the abnormality detection unit and the controller is not being performed normally, the edge module further includes an abnormality notification generation unit that generates an abnormality notification. The transmitter transmits the abnormality notification to the controller. The receiver function unit receives the abnormality notification. When the number of receptions of the abnormality notification reaches a predetermined number, the controller further includes a state determination function unit that determines an emergency. The remote control system according to claim 7.

10. A data generation function unit that generates second data including a serial number. A transmitter function unit that assigns a third time to the previous second data and transmits the second data to the edge module. A receiver function unit that receives third data including the serial number and the third time generated by the edge module based on the second data, and acquires a fourth time that is the time when the third data is received. An abnormality detection function unit that determines whether communication with the edge module has been performed normally based on at least one of the serial number included in the third data and the difference between the third time included in the third data and the fourth time. A controller comprising:

11. When at least one of the following conditions is satisfied: when there is a missing value in the serial number included in the third data, and when the difference between the third time and the fourth time is equal to or greater than a predetermined delay time, the abnormality detection function unit determines that the communication with the edge module is not being performed normally. The controller according to claim 10.

12. A virtual machine provided on the cloud. The controller according to claim 10.

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