Communication module, communication system, communication program, and communication method

Abstract

To provide a communication module, a communication system, a communication program, and a communication method capable of improving the convenience of workers.SOLUTION: A communication module 20 includes a wireless communication unit 27 that transmits and receives wireless communication frames to and from a terminal device 30, field communication units 21-25 that transmit and receive field communication frames to and from a field device 10, and a processing unit 26 that generates a field communication frame based on a wireless communication frame and generates a wireless communication frame based on the field communication frame. The processing unit 26 controls the field communication units 21-25 to select a protocol for modulating and demodulating a field communication frame in accordance with a protocol of the field device.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a communication module, a communication system, a communication program, and a communication method.

Background Art

[0002] As described in Patent Document 1, a handheld terminal device that communicates by being connected to field devices with signal lines is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When it is necessary to connect a terminal by wiring to communicate with field devices, the efficiency and safety of the work of communicating with field devices are reduced. That is, the convenience of the operator is reduced.

[0005] The present disclosure has been made in view of the above points, and an object thereof is to provide a communication module, a communication system, a communication program, and a communication method that can improve the convenience of an operator.

Means for Solving the Problems

[0006] (1) A communication module according to several embodiments comprises a wireless communication unit that transmits and receives wireless communication frames to and from a terminal device, a field communication unit that transmits and receives field communication frames to and from a field device, and a processing unit that generates the field communication frames based on the wireless communication frames and generates the wireless communication frames based on the field communication frames. The processing unit controls the field communication unit to select a protocol for modulating and demodulating the field communication frames to conform to the protocol of the field device.

[0007] The ability of the communication module to communicate wirelessly with terminal equipment reduces the need for wired connections. As a result, on-site work efficiency improves, and on-site costs are reduced. Furthermore, terminal equipment can be connected to field equipment without approaching or directly touching the field equipment. Consequently, maintenance work that communicates with field equipment can be performed remotely and safely.

[0008] The ability of the communication module to select modulation / demodulation protocols allows connection to any field device with just one terminal device. As a result, field work efficiency is improved, and field costs are reduced.

[0009] (2) In the communication module described in (1) above, the field communication unit may include a plurality of modulation / demodulation circuits that modulate / demodulate the field communication frame for each of a plurality of protocols, and a switching circuit that switches to one of the plurality of modulation / demodulation circuits and connects to the field device or the processing unit. The processing unit may control the switching circuit to select the protocol for modulating / demodulating the field communication frame. By using the switching circuit, the input / output circuit connected to the field device is unified into one.

[0010] (3) In the communication module described in (2) above, the switching circuit may be connected between the plurality of modulation / demodulation circuits and the field device. Each of the plurality of modulation / demodulation circuits may be connected to the processing unit by a UART communication line. By connecting each modulation / demodulation circuit to the processing unit by a UART communication line, a configuration can be made in which control lines are not required, depending on the design of the modulation / demodulation circuits.

[0011] (4) In the communication module described in (2) above, the switching circuit may be connected between the plurality of modulation / demodulation circuits and the processing unit. The switching circuit may be connected to the processing unit by a UART communication line. Each of the plurality of modulation / demodulation circuits may be connected between the switching circuit and the field device. By connecting the switching circuit to the processing unit, the price of the CPU of the processing unit is reduced. As a result, the cost of the processing unit is reduced.

[0012] (5) The communication module described in any one of (1) to (4) above may further include a relay terminal that branches the wiring from the field device to the external instrument room and the field communication unit. When the communication module is equipped with a relay terminal, terminal equipment can be connected at the location where the communication module is installed. As a result, the number of locations where terminal equipment can be connected increases.

[0013] (6) Some embodiments of a communication system include a communication module as described in any one of (1) to (5) above, a field device that transmits and receives the field communication frame to and from the communication module, and a terminal device that transmits and receives the wireless communication frame to and from the communication module.

[0014] (7) The communication system described in (6) above may further include relay terminals that branch the wiring from the field device to an external instrument room and to the field communication unit.

[0015] (8) A communication program according to some embodiments causes a processor to perform the following actions: to send and receive wireless communication frames with a terminal device; to send and receive field communication frames with a field device; to generate field communication frames based on the wireless communication frames; to generate wireless communication frames based on the field communication frames; and to select a protocol for modulating and demodulating the field communication frames to conform to the protocol of the field device.

[0016] (9) Some embodiments of communication methods are performed by a communication module that transmits and receives wireless communication frames to and from a terminal device and transmits and receives field communication frames to and from a field device. The communication method includes the communication module receiving the wireless communication frame from the terminal device, the communication module selecting a protocol for modulating and demodulating the field communication frame to conform to the protocol of the field device, generating the field communication frame based on the wireless communication frame using the selected protocol, and transmitting the field communication frame generated by the communication module to the field device.

[0017] (10) The communication method described in (9) above may further include the communication module receiving the field communication frame from the field device, the communication module generating the wireless communication frame based on the field communication frame using a protocol already selected, and the communication module transmitting the generated wireless communication frame to the terminal device.

[0018] (11) Some embodiments of communication methods are performed by a communication system comprising a field device, a terminal device, and a communication module that transmits and receives wireless communication frames to and from the terminal device and transmits and receives field communication frames to and from the field device. The communication method includes the terminal device transmitting the wireless communication frame to the communication module, the communication module receiving the wireless communication frame from the terminal device, the communication module selecting a protocol for modulating and demodulating the field communication frame to conform to the protocol of the field device, generating the field communication frame based on the wireless communication frame using the selected protocol, the communication module transmitting the generated field communication frame to the field device, and the field device receiving the field communication frame from the communication module.

[0019] (12) The communication method described in (11) above may further include: the field device transmitting the field communication frame to the communication module; the communication module receiving the field communication frame from the field device; the communication module generating the wireless communication frame based on the field communication frame using a protocol already selected; the communication module transmitting the generated wireless communication frame to the terminal device; and the terminal device receiving the wireless communication frame from the communication module. [Effects of the Invention]

[0020] The communication module, communication system, communication program, and communication method relating to this disclosure improve the convenience of the worker. [Brief explanation of the drawing]

[0021] [Figure 1] This is a diagram showing the system configuration related to the first comparative example. [Figure 2] This diagram shows the system configuration related to the second comparative example. [Figure 3] It is a schematic diagram showing a configuration example of a communication system according to an embodiment of the present disclosure. [Figure 4] It is a schematic diagram showing a configuration example of a communication system including a relay terminal. [Figure 5] It is a block diagram showing a configuration example of a communication module. [Figure 6] It is a schematic diagram of the flow of transmitting a communication frame from a user device to a field device. [Figure 7] It is a flowchart showing an example of a procedure for transmitting a communication frame from a user device to a field device using the communication module of FIG. 5. [Figure 8] It is a schematic diagram of the flow of transmitting a communication frame from a field device to a user device. [Figure 9] It is a flowchart showing an example of a procedure for transmitting a communication frame from a field device to a user device using the communication module of FIG. 5. [Figure 10] It is a block diagram of a communication system using one UART communication line. [Figure 11] It is a flowchart showing an example of a procedure for transmitting a communication frame from a user device to a field device in the communication system of FIG. 10. [Figure 12] It is a flowchart showing an example of a procedure for transmitting a communication frame from a field device to a user device in the communication system of FIG. 10. [Figure 13] It is an example of a block diagram of a communication system when the communication module incorporates a relay terminal. [Figure 14] It is a schematic diagram of the communication system of FIG. 13.

Embodiments for Carrying Out the Invention

[0022] This disclosure relates to a method for switching a communication protocol for communication between a product such as a two-wire field device and a user device. Examples of communication protocols that can be used include HART (Highway Addressable Remote Transducer), FF (Foundation Fieldbus), Profibus, or Modbus.

[0023] (Comparative example) As shown in Figure 1, the comparative example system 90 comprises a field device 91 and a user device 95. The field device 91 has a connection terminal 94. The field device 91 is a two-wire field device connected to a 24V power supply 92 and a load resistor 93 via the connection terminal 94. The field device 91 is wired to the user device 95 via the connection terminal 94. The user device 95 is a handheld terminal, tablet, or PC (Personal Computer), etc.

[0024] As shown in Figure 2, the system 90 relating to another comparative example includes a relay terminal 96. The relay terminal 96 is connected to the field device 91 and a distributor 97 located in an external instrument room 98.

[0025] In the comparative example system 90, in order to connect the user device 95 and the field device 91, it is necessary to remove the cover of the field device 91 and connect a cable to the internal connection terminal 94. Even if the system 90 is equipped with a relay terminal 96, it is still necessary to connect the user device 95 to the relay terminal 96.

[0026] When the user device 95 is connected via a wired connection, work efficiency is low. Specifically, the cable must be connected each time the field device 91 is adjusted or configured. The time required to connect the cable reduces work efficiency.

[0027] Furthermore, field equipment 91 may be installed in hazardous environments such as high places or radiation areas. If field equipment 91 is installed in a hazardous environment, connecting cables to field equipment 91 may lead to accidents.

[0028] The comparative example system 90 may include field devices 91 that communicate using different communication protocols. In this case, it is necessary to connect a different user device 95 for each communication protocol. In other words, a dedicated device is required for each communication protocol. When performing maintenance on field devices 91 that communicate using different communication protocols, it is necessary to prepare a user device 95 corresponding to each communication protocol. The preparation work is time-consuming, and transporting multiple user devices 95 reduces work efficiency. In addition, preparing multiple user devices 95 increases costs.

[0029] Therefore, this disclosure provides a communication module, communication system, communication program, and communication method that can improve the efficiency and safety of communication operations between field devices and terminals, thereby improving the convenience of the operator. I will explain this.

[0030] (Example configuration of communication system 1) A communication system 1 according to one embodiment of the present disclosure comprises a field device 10, a communication module 20, and a user device 30, as illustrated in Figure 3. The communication module 20 is connected to the field device 10. The field device 10 and the user device 30 communicate with each other via the communication module 20. The field device 10 and the communication module 20 communicate by wire or wirelessly based on a field communication protocol and send and receive field communication frames to each other. A field communication frame is communication data generated based on a field communication protocol. The user device 30 and the communication module 20 communicate wirelessly based on a wireless communication protocol and send and receive wireless communication frames to each other. A wireless communication frame is communication data generated based on a wireless communication protocol.

[0031] Because the communication module 20 is connected to the field device 10, the user device 30 can communicate wirelessly with the field device 10 via the communication module 20. Therefore, there is no need to perform wiring work between the user device 30 and the field device 10 in order to connect the user device 30 to the field device 10.

[0032] Furthermore, because the communication module 20 communicates with the field device 10 based on the field communication protocol, the user device 30 can communicate with the field device 10 based on the wireless communication protocol, regardless of the field communication protocol. Therefore, there is no need to prepare a user device 30 that conforms to the field communication protocol of the field device 10.

[0033] A communication system 1 according to another embodiment of the present disclosure further comprises a relay terminal 40, as illustrated in Figure 4. The relay terminal 40 comprises a terminal 41 for connection to a field device 10 and a terminal 42 for connection to a communication module 20 and a distributor 60 installed in an external instrument room 50.

[0034] The relay terminal 40 merges the communication frames transmitted from the distributor 60 to the field device 10 and the communication frames transmitted from the user device 30 to the field device 10. The relay terminal 40 also splits the communication frames transmitted from the field device 10 to the distributor 60 and the user device 30.

[0035] Instrument room 50 is the room where the plant's control systems are installed.

[0036] The distributor 60 is a device that distributes power to field devices, receives output signals from the devices, and outputs signals to a higher-level system. The distributor 60 may be installed in a control panel. The control panel may be located in a room such as the instrument room 50.

[0037] The following describes an example of the configuration of each part of communication system 1.

[0038] <Field device 10> The field device 10 measures physical quantities in various parts of the plant or controls various parts of the plant in order to operate the plant safely. The field device 10 may output a measurement signal corresponding to the physical quantity to be measured detected by, for example, a sensor. The field device 10 may convert analog measurement data into digital data and output it as serial data. The field device 10 may control, for example, a valve, based on a control signal input from the user device 30. The field device 10 includes, for example, a differential pressure transmitter, a pressure transmitter, a temperature transmitter, or a flow meter.

[0039] In the communication system 1 described herein, the field device 10 is connected to the communication module 20 by a wire, and transmits and receives communication frames wirelessly with the user device 30 via the communication module 20.

[0040] The field device 10 performs field communication with devices other than itself using a protocol specific to the field device 10. The protocol used by the field device 10 for field communication is also called the field communication protocol. The field communication protocol may be, for example, HART, FF, Profibus, or Modbus.

[0041] <Communication Module 20> The communication module 20 transmits data received from the user device 30 via parallel or serial communication to the field device 10 via serial communication. The communication module 20 also transmits data received from the field device 10 via serial communication to the user device 30 via parallel or serial communication.

[0042] The communication module 20 is connected to the field device 10 via a wired connection. The communication module 20 may be directly connected to the field device 10, or it may be connected to the field device 10 via a relay terminal 40. The communication module 20 is also connected to the user device 30 wirelessly.

[0043] As illustrated in Figure 5, the communication module 20 includes a switching circuit 21, a HART modulation / demodulation circuit 22, an FF modulation / demodulation circuit 23, a Profibus modulation / demodulation circuit 24, a Modbus modulation / demodulation circuit 25, a CPU (Central Processing Unit) 26, a wireless IC (Integrated Circuit) 27, and a power supply 28. The number of modulation / demodulation circuits is not limited to four; it may be two, three, or five or more. In other words, the communication module 20 only needs to have at least two modulation / demodulation circuits.

[0044] The wireless IC 27 is configured to communicate wirelessly with the user device 30. The wireless IC 27 is also referred to as the wireless communication unit. The wireless IC 27 may include an antenna for transmitting and receiving wireless radio waves. The wireless IC 27 converts the wireless radio waves received from the user device 30 into electrical signals and outputs them to the CPU 26. The wireless IC 27 also converts electrical signals input from the CPU into wireless radio waves and transmits them to the user device.

[0045] The wireless IC27 is configured to perform wireless communication based on general-purpose wireless communication protocols such as Wi-Fi (registered trademark), Bluetooth (registered trademark), BLE (Bluetooth Low Energy), LTE (Long Term Evolution), or 4G (4th Generation) or 5G (5th Generation).

[0046] When transmitting data from the user device 30 to the field device 10, the CPU 26 recognizes the wireless communication frame received from the user device 30 based on the electrical signal acquired from the wireless IC 27. The wireless communication frame includes a preamble, a payload, and an error detection code such as a CRC (Cyclic Redundancy Check). The wireless communication frame may also include an error correction code. The preamble is data that indicates the start of transmission of the communication frame. The payload is data that includes commands to be transmitted from the user device 30 to the field device 10.

[0047] The CPU 26 analyzes the payload contained in the wireless communication frame. The CPU 26 analyzes the payload and recognizes the field communication protocol for transmitting data to the field device 10.

[0048] When transmitting data from the field device 10 to the user device 30, the CPU 26 generates an electrical signal to be output to the wireless IC 27 based on the field communication frame received from the field device 10. Specifically, the CPU 26 uses the field communication frame as a payload, adds a preamble and error detection code to generate a wireless communication frame, converts the wireless communication frame into an electrical signal, and outputs it to the wireless IC 27.

[0049] The CPU 26 is also called the processing unit. The CPU 26 may be replaced with a general-purpose processor, or with a dedicated circuit such as an FPGA (Field Programmable Gate Array). The CPU 26 may also be replaced with a configuration that combines a processor and a dedicated circuit. The CPU 26 may be configured to execute programs that realize various functions of the communication module 20. The CPU 26 may have a memory unit. The memory unit may store various information used for the operation of the CPU 26, or programs for realizing the functions of the CPU 26. The memory unit may function as the work memory of the CPU 26. The memory unit may be composed of, for example, semiconductor memory. The memory unit may be configured separately from the CPU 26.

[0050] The CPU26 is connected to each modulation / demodulation circuit via UART (Universal Asynchronous Receiver Transmitter) communication lines. The UART communication lines are attached to the CPU26 and are allocated to each modulation / demodulation circuit.

[0051] In the example in Figure 5, the CPU 26 is connected to the HART modulation / demodulation circuit 22 by a UART communication line labeled UART1. The CPU 26 is connected to the FF modulation / demodulation circuit 23 by a UART communication line labeled UART2. The CPU 26 is connected to the Profibus modulation / demodulation circuit 24 by a UART communication line labeled UART3. The CPU 26 is connected to the Modbus modulation / demodulation circuit 25 by a UART communication line labeled UART4.

[0052] The HART modulation / demodulation circuit 22 is a circuit that modulates and demodulates the field communication frame at a frequency suitable for HART communication when the field communication protocol of the field device 10 is HART.

[0053] The FF modulation / demodulation circuit 23 is a circuit that modulates and demodulates the field communication frame at a frequency suitable for FF communication when the field communication protocol of the field device 10 is FF.

[0054] The Profibus modulation / demodulation circuit 24 is a circuit that modulates and demodulates field communication frames at frequencies suitable for Profibus communication when the field communication protocol of the field device 10 is Profibus.

[0055] The Modbus modulation / demodulation circuit 25 is a circuit that modulates and demodulates field communication frames at frequencies suitable for Modbus communication when the field communication protocol of the field device 10 is Modbus.

[0056] Each modulation / demodulation circuit is connected to the field device 10 via a switching circuit 21. The switching circuit 21 switches the wiring to selectively connect one of the multiple modulation / demodulation circuits to the field device 10. In other words, the switching circuit 21 can unify the wiring for inputting and outputting data between the multiple modulation / demodulation circuits and the field device 10 into a single wire. To put it another way, the input / output circuit connecting the field device 10 and the communication module 20 is unified into one.

[0057] The switching circuit 21 may include an electronic switch such as a switch IC. The switching circuit 21 may also include a switch that mechanically opens and closes contacts such as a relay.

[0058] The switching circuit 21 and the multiple modulation / demodulation circuits are collectively referred to as the field communication section.

[0059] The power supply 28 supplies power to the electrical circuits or components included in the communication module 20. The power supply 28 may include an external power supply or bus power. The power supply 28 may also include an internal power supply such as a primary battery, a secondary battery, or a capacitor.

[0060] <User device 30> The user device 30 is a device that provides a user interface for the user to access the field device 10. The user device 30 transmits and receives data to and from the field device 10 via the communication module 20 by wireless communication with the communication module 20.

[0061] In the communication system 1 relating to this disclosure, the user device 30 can recognize the field communication protocol of the field device 10 with which it will communicate before initiating communication with the field device 10. For example, the user device 30 may have a function to register the device information of the field device 10 in advance. The device information of the field device 10 includes the field communication protocol of the field device 10. When connecting with the field device 10, the user device 30 may verify the device information registered in the user device 30 in advance and recognize the field communication protocol to be used for communication with the field device 10.

[0062] The user device 30 is also called a terminal device and may include, for example, a tablet, a notebook PC (Personal Computer), or a smartphone.

[0063] (Example of operation of communication system 1) The following describes an example of communication between the user device 30 and the field device 10 in the communication system 1 related to this disclosure.

[0064] The communication module 20 converts between the field communication protocol of the field device 10 and the wireless communication protocol of the user device 30. As described above, the field communication protocol includes HART, FF, Profibus, or Modbus, etc. The wireless communication protocol includes Wi-Fi®, Bluetooth®, BLE, LTE, or 4G or 5G, etc.

[0065] In the communication system 1 described herein, the communication module 20 switches to one of a plurality of modulation / demodulation circuits depending on the difference in the field communication protocol of the field device 10 to which it is connected. By switching between the plurality of modulation / demodulation circuits, the communication module 20 can modulate and demodulate the field communication frames transmitted and received with the field device 10, regardless of the field communication protocol of the field device 10 to which it is connected.

[0066] The communication module 20 may be configured such that multiple UART communication lines are attached to the CPU 26, as illustrated in Figure 5. Alternatively, the communication module 20 may be configured such that one UART communication line is attached to the CPU 26, as will be described later. Below, examples of operation when the communication module 20 is configured in each of these configurations will be explained.

[0067] <When multiple UART communication lines are used> As illustrated in Figure 5, the communication module 20 is provided with multiple UART communication lines connecting the CPU 26 to each of the multiple modulation / demodulation circuits. Since each modulation / demodulation circuit is connected to the CPU 26 by a UART communication line, it becomes possible to configure the circuit in a way that eliminates the need for control lines.

[0068] <<When transmitting data from user device 30 to field device 10>> As illustrated in Figure 6, the user device 30 creates a wireless communication frame containing a payload and transmits it wirelessly to the communication module 20. The payload corresponds to a field communication frame that the field device 10 can receive. The payload may include a command requesting the field device 10 to transmit data such as sensor measurements or parameter values ​​set on the field device 10. The payload may include a command causing the field device 10 to set parameters. The payload may include various data or information, but is not limited to these examples.

[0069] The communication module 20 receives a wireless communication frame from the user device 30, extracts and analyzes the payload from the wireless communication frame, and creates a field communication frame to be transmitted to the field device 10. The communication module 20 then transmits the field communication frame to the field device 10.

[0070] The field device 10 receives a field communication frame.

[0071] The user device 30, communication module 20, and field device 10 of the communication system 1 may perform a communication method including the steps of the flowchart illustrated in Figure 7. At least some of the steps of the communication method may be implemented as a communication program to be executed by the CPU 26 of the communication module 20. The communication program may be stored on a non-temporary computer-readable medium.

[0072] The user device 30 determines the communication protocol (step S1). For example, the user device 30 may determine the field communication protocol to be used for connection with the field device 10 by comparing the device information of the field device 10 to be connected to, based on the device information of the field device 10 that has been registered in the user device 30 in advance.

[0073] The user device 30 generates a wireless communication frame and transmits the wireless communication frame to the communication module 20 (step S2). The wireless communication frame includes a preamble, a payload, and an error detection code such as a CRC. The payload is a field communication frame that conforms to the field communication protocol used by the field device 10 to which it is connected. After performing the procedure in step S2, the user device 30 completes the procedure in the flowchart of Figure 7.

[0074] The wireless IC 27 of the communication module 20 receives a wireless communication frame (step S3). The wireless IC 27 outputs the wireless communication frame to the CPU 26 of the communication module 20 (step S4). The CPU 26 of the communication module 20 receives the wireless communication frame from the wireless IC 27 and extracts the payload from the wireless communication frame (step S5).

[0075] The CPU 26 identifies which field communication protocol the payload content corresponds to (step S6). The CPU 26 may identify the field communication protocol, for example, by comparing the payload content with the format of each field communication protocol. The format is information that defines the arrangement or format of data included in the communication frame, which can be recognized in each field communication protocol. The CPU 26 can determine the type of protocol based on the type of format. The CPU 26 may also identify the field communication protocol, for example, based on an identifier attached to the payload. The identifier may be an ID assigned to each type of protocol.

[0076] The CPU 26 controls the switching circuit 21 and selects a modulation / demodulation circuit that conforms to the identified field communication protocol (step S7). The CPU 26 outputs the field communication frame to the selected modulation / demodulation circuit by outputting the field communication frame to the UART communication line connected to the selected modulation / demodulation circuit. The CPU 26 outputs the payload of the wireless communication frame received from the user device 30 as the field communication frame.

[0077] The modulation / demodulation circuit selected by the CPU 26 modulates and demodulates the field communication frame (step S8). The communication module 20 transmits the field communication frame, which has been modulated and demodulated by the modulation / demodulation circuit selected by the CPU 26, to the field device 10 (step S9). After executing the procedure in step S9, the communication module 20 completes the execution of the procedure in the flowchart of Figure 7.

[0078] The field device 10 receives a field communication frame (step S10). After performing the procedure in step S10, the field device 10 completes the procedure in the flowchart in Figure 7.

[0079] In communication system 1, the procedures described above are executed, thereby transmitting commands and other information from user device 30 to field device 10.

[0080] <<When transmitting data from user device 30 to field device 10>> As illustrated in Figure 8, the field device 10 creates a field communication frame and transmits it to the communication module 20. The field communication frame may include data such as sensor measurements, calculated values ​​performed by the field device 10, or parameter values ​​set on the field device 10. The field communication frame may also include the results of executing commands to the field device 10.

[0081] The communication module 20 receives a field communication frame from the field device 10 and creates a wireless communication frame by adding a preamble and CRC to the field communication frame as a payload. The communication module 20 transmits the wireless communication frame to the user device 30.

[0082] The user device 30 receives a wireless communication frame.

[0083] The field device 10, communication module 20, and user device 30 of communication system 1 may perform a communication method including the steps of the flowchart illustrated in Figure 9. At least some of the steps of the communication method may be implemented as a communication program to be executed by the CPU 26 of the communication module 20. The communication program may be stored on a non-temporary computer-readable medium.

[0084] The field device 10 generates a field communication frame and transmits it to the communication module 20 using the field communication protocol (step S11). The field communication frame includes data or information to be transmitted from the field device 10 to the user device 30. After performing the procedure in step S11, the field device 10 completes the procedure in the flowchart of Figure 9.

[0085] The communication module 20 receives the field communication frame in the switching circuit 21 (step S12). The communication module 20 modulates and demodulates the field communication frame using the modulation / demodulation circuit already selected in the switching circuit 21, and outputs the modulated and demodulated field communication frame to the CPU 26 (step S13). Specifically, the switching circuit 21 outputs the field communication frame to the modulation / demodulation circuit that was already selected when the user device 30 sent a command or the like to the field device 10. In other words, the communication module 20 makes the selection of the modulation / demodulation circuit in the switching circuit 21 the same when the user device 30 sends a command or the like to the field device 10, and when the field device 10 sends data or information to the user device 30. The modulation / demodulation circuit that receives the field communication frame from the switching circuit 21 modulates and demodulates the field communication frame, and outputs the modulated and demodulated field communication frame to the CPU 26 via the UART communication line.

[0086] The CPU 26 generates a wireless communication frame using the field communication frame as the payload (step S14). The CPU 26 outputs the generated wireless communication frame to the wireless IC 27. The wireless IC 27 transmits the wireless communication frame to the user device 30 (step S15). After executing the procedure in step S15, the communication module 20 completes the execution of the procedure in the flowchart in Figure 9.

[0087] The user device 30 receives a wireless communication frame (step S16). After performing the procedure in step S16, the user device 30 completes the procedure in the flowchart in Figure 9.

[0088] In the communication system 1, the procedures described above are executed, and measurement values ​​and other information are transmitted from the field device 10 to the user device 30.

[0089] In the procedure example described above, the field device 10 transmits measured values, etc., to the user device 30 in response to commands, etc., received from the user device 30. When the field device 10 receives a request for burst communication from the user device 30, it performs burst communication until it receives a request from the user device 30 to stop the burst communication. Burst communication is the continuous transmission of measured values, etc., from the field device 10 at a fixed interval. When the field device 10 performs burst communication, the procedure in the flowchart of Figure 9 described above is repeated.

[0090] (summary) As described above, with the communication system 1 and communication module 20 related to this disclosure, even if the field device 10 is specified to communicate via a wired connection, wireless communication between the field device 10 and the user device 30 becomes possible by connecting the communication module 20.

[0091] As a comparative example, if the communication module 20 is not connected to the field device 10, the user device 30 must be connected to the field device 10 via a wired connection each time the field device 10, which is designed for wired communication, needs to communicate with the user device 30. To connect to the field device 10 via a wired connection, the cover of the field device 10 must be opened and the wiring performed. The wiring work alone takes several minutes per unit. If dozens of field devices 10 are to be connected, the wiring work alone will take several hours.

[0092] On the other hand, according to the communication system 1 and communication module 20 described herein, user devices 30 can connect to field equipment 10 wirelessly and complete communication in a few seconds per device. Therefore, the time required to connect user devices 30 to field equipment 10 is reduced. As a result, on-site work efficiency is improved, and on-site costs are reduced.

[0093] Furthermore, in the comparative example, in order to connect the user device 30 to the field device 10 via a wire, it is necessary to approach the field device 10 and touch it directly to perform the work. If the field device 10 is installed in a hazardous environment such as a high place or a radiation area, approaching or directly touching the field device 10 may lead to an accident.

[0094] On the other hand, according to the communication system 1 and communication module 20 described herein, the user device 30 is connected to the field device 10 by wireless communication, without approaching or directly touching the field device 10. As a result, maintenance work that communicates with the field device 10 can be performed remotely and safely.

[0095] Furthermore, according to the communication system 1 and communication module 20 described herein, regardless of the field communication protocol of the field device 10, the field communication frame is modulated and demodulated so that it can be transmitted and received with the user device 30 by the selection of an appropriate modulation / demodulation circuit by the switching circuit 21.

[0096] As a comparative example, if an appropriate modulation / demodulation circuit is not selected, a user device 30 that conforms to the field communication protocol of the field device 10 must be prepared in order to communicate with the field device 10. If field devices 10 with multiple field communication protocols are present in the plant, it will be necessary to bring and use multiple user devices 30.

[0097] On the other hand, with the communication system 1 and communication module 20 described herein, by selecting an appropriate modulation / demodulation circuit, connection to any field device 10 is possible by preparing only one user device 30. As a result, on-site work efficiency is improved, and on-site costs are reduced.

[0098] As described above, the communication system 1 and communication module 20 relating to this disclosure can improve work efficiency and safety by facilitating maintenance work on the field equipment 10, as well as reduce on-site costs.

[0099] (Other embodiments) The following describes an example configuration of the communication module 20 according to another embodiment.

[0100] <When connecting to multiple modulation / demodulation circuits using a single UART communication line> As illustrated in Figure 10, the communication module 20 may connect the CPU 26 and multiple modulation / demodulation circuits with a single UART communication line. In this case, the single UART communication line connects the CPU 26 and the switching circuit 21. By connecting the switching circuit 21 to the CPU 26, the price of the CPU 26 is reduced. As a result, the cost of the CPU 26 is reduced.

[0101] The switching circuit 21 connects to multiple modulation / demodulation circuits. In other words, the CPU 26 connects to multiple modulation / demodulation circuits via the switching circuit 21. The UART communication line transmits and receives field communication frames between each modulation / demodulation circuit and the CPU 26.

[0102] The CPU 26 is connected to the switching circuit 21 via a control signal line in order to control the switching circuit 21. The control signal line is a communication line that controls the switching circuit 21. The CPU 26 analyzes the field communication frame and, if it determines that it is necessary to switch the modulation / demodulation circuit that modulates / demodulates the field communication frame, it sends a control signal to the switching circuit 21 to switch to the appropriate modulation / demodulation circuit.

[0103] The configuration of each modulation / demodulation circuit, wireless IC 27, and power supply 28 may be the same as the configuration example in the communication module 20 shown in Figure 5.

[0104] <<When transmitting data from user device 30 to field device 10>>

[0105] The user device 30, communication module 20, and field device 10 of the communication system 1 may perform a communication method including the steps of the flowchart illustrated in Figure 11. At least some of the steps of the communication method may be implemented as a communication program to be executed by the CPU 26 of the communication module 20. The communication program may be stored on a non-temporary computer-readable medium.

[0106] The user device 30 determines the communication protocol (step S21). The procedure in step S21 may be the same as the procedure in step S1 in Figure 7. The user device 30 generates a wireless communication frame and transmits the wireless communication frame to the communication module 20 (step S22). The procedure in step S22 may be the same as the procedure in step S2 in Figure 7. After performing the procedure in step S22, the user device 30 finishes performing the procedure in the flowchart in Figure 11.

[0107] The wireless IC 27 of the communication module 20 receives a wireless communication frame (step S23). The wireless IC 27 outputs the wireless communication frame to the CPU 26 of the communication module 20 (step S24). The CPU 26 of the communication module 20 receives the wireless communication frame from the wireless IC 27 and extracts the payload from the wireless communication frame (step S25). Steps S23 to S25 may be the same as steps S3 to S5 in Figure 7.

[0108] The CPU 26 identifies which field communication protocol the payload contents correspond to (step S26). The procedure in step S26 may be the same as the procedure in step S6 in Figure 7.

[0109] The CPU 26 controls the switching circuit 21 via a control signal line and selects a modulation / demodulation circuit that conforms to the identified field communication protocol (step S27). The CPU 26 outputs the field communication frame to only one UART line. The CPU 26 outputs the payload of the wireless communication frame received from the user device 30 as a field communication frame. The field communication frame is input only to the modulation / demodulation circuit selected by the switching circuit 21.

[0110] The modulation / demodulation circuit that receives the field communication frame modulates / demodulates the field communication frame (step S28). In other words, the field communication frame is modulated / demodulated only by the selected modulation / demodulation circuit. The communication module 20 transmits the field communication frame from the selected modulation / demodulation circuit (step S29). After executing the procedure in step S29, the communication module 20 completes the execution of the procedure in the flowchart of Figure 11.

[0111] The field device 10 receives a field communication frame (step S30). After performing the procedure in step S30, the field device 10 completes the procedure in the flowchart of Figure 11.

[0112] In communication system 1, the procedures described above are executed, thereby transmitting commands and other information from user device 30 to field device 10.

[0113] <<When transmitting data from field device 10 to user device 30>> The field device 10, communication module 20, and user device 30 of communication system 1 may perform a communication method including the steps of the flowchart illustrated in Figure 12. At least some of the steps of the communication method may be implemented as a communication program to be executed by the CPU 26 of the communication module 20. The communication program may be stored on a non-temporary computer-readable medium.

[0114] The field device 10 generates a field communication frame and transmits it to the communication module 20 using the field communication protocol (step S31). The procedure in step S31 may be the same as the procedure in step S11 in Figure 9. After performing the procedure in step S31, the field device 10 completes the execution of the procedure in the flowchart in Figure 12.

[0115] The communication module 20 receives a field communication frame (step S32). The selected modulation / demodulation circuit of the communication module 20 modulates / demodulates the field communication frame (step S33). The selected modulation / demodulation circuit is the one that was already selected when the user device 30 sent a command or the like to the field device 10. The switching circuit 21 outputs the modulated / demodulated field communication frame from the selected modulation / demodulation circuit to the CPU 26 (step S34). In other words, the communication module 20 uses the same modulation / demodulation circuit selected by the switching circuit 21 when the user device 30 sends a command or the like to the field device 10 and when the field device 10 sends data or information to the user device 30.

[0116] The CPU 26 generates a wireless communication frame using the field communication frame as the payload (step S35). The CPU 26 outputs the generated wireless communication frame to the wireless IC 27. The wireless IC 27 transmits the wireless communication frame to the user device 30 (step S36). The steps in steps S35 and S36 may be the same as the steps in steps S14 and S15 in Figure 9. After executing the step in step S36, the communication module 20 finishes executing the steps in the flowchart in Figure 12.

[0117] The user device 30 receives a wireless communication frame (step S37). After performing the procedure in step S37, the user device 30 completes the procedure in the flowchart of Figure 12.

[0118] In the communication system 1, the procedures described above are executed, and measurement values ​​and other information are transmitted from the field device 10 to the user device 30.

[0119] In the procedure example described above, the field device 10 transmits measured values, etc., to the user device 30 in response to commands, etc., received from the user device 30. When the field device 10 receives a request for burst communication from the user device 30, it performs burst communication until it receives a request from the user device 30 to stop the burst communication. When the field device 10 performs burst communication, the procedure in the flowchart of Figure 12 described above is repeated.

[0120] <When the communication module 20 has a built-in relay terminal 40> As illustrated in Figures 13 and 14, the communication module 20 may incorporate a relay terminal 40. The configuration of the communication module 20 differs from the configuration example in Figure 5 only in that a relay terminal 40 has been added.

[0121] If the relay terminal 40 is not built into the communication module 20, it is installed as a separate relay terminal box within the plant. In that case, when using the user device 30 in a location other than where the field device 10 is located, the only place where the user device 30 can be connected is where the relay terminal box is installed.

[0122] If the communication module 20 has a built-in relay terminal 40, the user device 30 can be connected at the location where the communication module 20 is installed. As a result, the number of locations where the user device 30 can be connected within the plant increases. Furthermore, by installing the communication module 20 at any location within the plant, the locations where the user device 30 can be connected can be freely set.

[0123] <Example of how to recognize a field communication protocol> As described above, the user device 30 may determine the field communication protocol to be used for connection with the field device 10 by comparing the device information of the field device 10 to be connected to the user device 30 based on the device information of the field device 10 that has been registered in the user device 30 in advance. The user device 30 may determine the field communication protocol by other means.

[0124] For example, user device 30 may create field communication frames based on each of several field communication protocols assumed to be the field communication protocol of field device 10 and send them to field device 10. Assume that the field communication frame is a command requesting acknowledgment of receipt. When field device 10 receives a field communication frame based on its own field communication protocol, it understands the command and sends an acknowledgment of receipt. On the other hand, when field device 10 receives a field communication frame not based on its own field communication protocol, it cannot understand the command and does not send an acknowledgment of receipt. In this case, user device 30 can determine that the field communication protocol from which it received an acknowledgment of receipt is the field communication protocol of field device 10.

[0125] While embodiments relating to this disclosure have been described above with reference to the drawings, the specific configuration is not limited to these embodiments and may include various modifications without departing from the spirit of this disclosure. [Explanation of Symbols]

[0126] 1. Communication System 10 Field Equipment 20. Communication module (21-25: Field communication section (21: Switching circuit, 22: HART modulation / demodulation circuit, 23: FF modulation / demodulation circuit, 24: Profibus modulation / demodulation circuit, 25: Modbus modulation / demodulation circuit), 26: CPU (processing unit), 27: Wireless IC (wireless communication section), 28: Power supply) 30. User devices (terminal equipment) 40 Relay terminals (41, 42: terminals) 50 Instrument Room 60 Distributors

Claims

1. A wireless communication unit that transmits and receives wireless communication frames with terminal devices, A field communication unit that transmits and receives field communication frames with field devices, A processing unit that generates the field communication frame based on the wireless communication frame, and generates the wireless communication frame based on the field communication frame. Equipped with, The field communication unit comprises a plurality of modulation / demodulation circuits that modulate / demodulate the field communication frame for each of the plurality of protocols, and a switching circuit connected between the plurality of modulation / demodulation circuits and the field device or the processing unit, which switches to one of the plurality of modulation / demodulation circuits. The processing unit controls the switching circuit to select a modulation / demodulation circuit that modulates / demodulates the field communication frame using a protocol compatible with the field device's protocol. Communication module.

2. Each of the plurality of modulation / demodulation circuits is connected to the processing unit by a UART communication line. The communication module according to claim 1.

3. The switching circuit is connected to the processing unit by a UART communication line, Each of the plurality of modulation / demodulation circuits is connected between the switching circuit and the field device. The communication module according to claim 1.

4. The communication module according to any one of claims 1 to 3, further comprising a relay terminal for branching the wiring from the field device to an external instrument room and the field communication unit.

5. A communication module according to any one of claims 1 to 3, The field device transmits and receives the field communication frame with the communication module, The terminal device that transmits and receives the wireless communication frame with the communication module A communication system equipped with these features.

6. The communication system according to claim 5, further comprising a relay terminal that branches the wiring from the field device to an external instrument room and the field communication unit.

7. Sending and receiving wireless communication frames between terminal devices, Sending and receiving field communication frames with field devices, To generate the field communication frame based on the wireless communication frame, To generate the wireless communication frame based on the field communication frame, The system controls a switching circuit connected between a plurality of modulation / demodulation circuits that modulate / demodulate the field communication frame for each of the plurality of protocols and a processing unit that generates the field device or the wireless communication frame, and switches to one of the plurality of modulation / demodulation circuits, thereby selecting a modulation / demodulation circuit that modulates / demodulates the field communication frame using a protocol that is compatible with the protocol of the field device. A communication program that causes the processor to execute.

8. A communication method performed by a communication module that transmits and receives wireless communication frames with terminal equipment and transmits and receives field communication frames with field equipment, The communication module receives the wireless communication frame from the terminal device, The communication module controls a switching circuit that is connected between a plurality of modulation / demodulation circuits that modulate / demodulate the field communication frame in each of a plurality of protocols and a processing unit that generates the field device or the wireless communication frame, and switches to one of the plurality of modulation / demodulation circuits to select a modulation / demodulation circuit that modulates / demodulates the field communication frame in a protocol that is compatible with the protocol of the field device, and generates the field communication frame based on the wireless communication frame using the selected modulation / demodulation circuit. The communication module transmits the generated field communication frame to the field device. A communication method that includes this.

9. The communication module receives the field communication frame from the field device, The communication module generates the wireless communication frame based on the field communication frame using a previously selected modulation / demodulation circuit, The communication module transmits the generated wireless communication frame to the terminal device. The communication method according to claim 8, further comprising:

10. A communication method performed by a communication system comprising a field device, a terminal device, and a communication module that transmits and receives wireless communication frames to and from the terminal device and transmits and receives field communication frames to and from the field device, The terminal device transmits the wireless communication frame to the communication module, The communication module receives the wireless communication frame from the terminal device, The communication module controls a switching circuit that is connected between a plurality of modulation / demodulation circuits that modulate / demodulate the field communication frame in each of a plurality of protocols and a processing unit that generates the field device or the wireless communication frame, and switches to one of the plurality of modulation / demodulation circuits to select a modulation / demodulation circuit that modulates / demodulates the field communication frame in a protocol that is compatible with the protocol of the field device, and generates the field communication frame based on the wireless communication frame using the selected modulation / demodulation circuit. The communication module transmits the generated field communication frame to the field device. The field device receives the field communication frame from the communication module. A communication method that includes this.

11. The field device transmits the field communication frame to the communication module, The communication module receives the field communication frame from the field device, The communication module generates the wireless communication frame based on the field communication frame using a previously selected modulation / demodulation circuit, The communication module transmits the generated wireless communication frame to the terminal device, The terminal device receives the wireless communication frame from the communication module. The communication method according to claim 10, further comprising:

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