JP6496874B1 - Communications system - Google Patents

Abstract

A wireless communication device capable of wirelessly relaying communication of a field device installed in a plant with high reliability.
A wireless communication device is connected to a field device of a plant through a signal line. The wireless communication device includes a signal input unit 21 that generates signal data D obtained by converting the signal value of the input signal S input from the signal line 71, a wireless communication unit 3 for transmitting signal data wirelessly, and the like. At least one of the inter-device communication unit 4 connected to the wireless communication device by wire and the wireless communication processing of the signal data via the wireless communication unit or the bypass communication processing of the signal data via the inter-device communication unit And a communication processing unit 5 for executing
[Selection] Figure 2

Description

The present disclosure relates to a communication system including a wireless communication device connected to a field device installed in a plant and wirelessly communicating (relaying) an input / output signal of the field device.

  Usually, a plant is provided with a large number of field devices serving as operation terminals such as measuring instruments (transmitters) such as differential pressure transducers and temperature transducers, and control valves. These field devices are connected to the control device, and periodically send measurement values such as temperature, flow rate, pressure, etc. to the control device, or receive operation commands received from the control device (for example, command values for valve opening, etc.) Or work according to. At this time, input / output to / from the field device is performed with a DC analog signal of 4 to 20 mA, and the measurement value and the contents of the operation command are communicated with the signal value of the analog signal. By superimposing (frequency modulation) an AC digital signal on the DC analog signal, it is also possible to simultaneously communicate a plurality of information. Such a communication method is a hybrid communication such as HART communication (smart communication). ).

  Conventionally, these various field devices and the control device are connected by individual signal lines. In recent years, in order to reduce wiring costs and maintenance costs, wireless communication between field devices and control devices has been promoted (see Patent Document 1). For example, in Patent Document 1, a wireless relay device to which a plurality of field devices are connected converts an analog signal input from each field device into data (digital data), and wirelessly transmits signal data that is converted into a converted analog signal. Data communication is performed with respect to a control device connected via a LAN. Patent Document 1 also discloses that a switching unit is provided for connecting a wireless relay device to a control device not only wirelessly but also by wire, and switching to wired communication or wireless communication depending on the state of the communication path.

JP 2005-333189 A

  In general, wireless communication (wireless connection) is used for wired communication (wired connection) because the communication quality changes depending on the radio wave conditions, such as the communication speed becomes slow and the communication becomes unstable if the radio wave is difficult to reach. Compared to reliability. For this reason, the wireless connection between the field device and the control device is easy to apply to data collection regardless of the real-time property as long as the measurement target can be measured at a low frequency, but the real-time property is important. Such control commands and application to the collection of important data are not easy because a short stoppage can be fatal to the operation of the plant. For this reason, for example, as disclosed in Patent Document 1, if the communication path between the field device and the control device is wirelessly and wiredly duplicated, the wiring cost required for wired connection is required, and thus the benefits of wirelessization are sufficient. I can't get it.

  In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a wireless communication device that can wirelessly relay field devices installed in a plant with high reliability.

(1) A wireless communication device according to at least one embodiment of the present invention includes:
A wireless communication device connected to a field device of a plant via a signal line,
A signal input unit that generates signal data obtained by converting a signal value of an input signal input from the signal line;
A wireless communication unit for wirelessly transmitting the signal data;
An inter-device communication unit connected by wire to other wireless communication devices;
A communication processing unit that executes at least one of the communication processing of the signal data via the wireless communication unit or the bypass communication processing of the signal data via the inter-device communication unit.

  According to the configuration of (1) above, when the wireless communication device transmits signal data to a communication destination such as a plant control device, for example, the wireless communication device transmits wirelessly from its own device and another wirelessly connected wireless device. It is configured to be able to transmit via a communication device. Therefore, for example, when the surrounding radio wave condition is good, signal data is transmitted wirelessly from the own device, and when the radio wave condition is bad, another wireless communication device in which the surrounding radio wave condition is good is used. It is possible to transmit signal data through the network. As a result, signal data can be more reliably communicated from the wireless communication device to the communication destination.

(2) In some embodiments, in the configuration of (1) above,
And a power supply unit configured to supply driving power to the field device via the signal line.

  According to the configuration of (2) above, the wireless communication device has the function of a distributor (power supply device), and supplies power to the field device via the signal line. As a result, power can be supplied to the field device. Moreover, the power supply device (distributor) which supplies power via a signal line from the control device side, which has been necessary in the past, can be eliminated, and the cost of the plant can be suppressed.

(3) In some embodiments, in the above configurations (1) to (2),
A data sharing unit for storing the signal data generated by the signal input unit and the signal data generated by the other wireless communication device received via the inter-device communication unit;
The communication processing unit executes at least the bypass communication process.

  According to the configuration of (3) above, the wireless communication device transmits the signal data generated by itself to another wireless communication device, and receives and stores (stores) the signal data generated by the other wireless communication device. ) In other words, the plurality of wireless communication devices are configured to communicate each other's signal data generated by each wireless communication device between the devices regardless of surrounding radio wave conditions and share each other's signal data. In this way, as long as there is at least one wireless communication device having a good radio wave condition, signal data can be transmitted from the wireless communication device to the communication destination in a timely manner. Therefore, it is possible to reliably perform signal data communication from the wireless communication device to the communication destination in real time.

(4) In some embodiments, in the configuration of (3) above,
When the communication processing unit receives the transmission request for the signal data via the wireless communication unit, the communication processing unit executes the wireless communication processing and transmits at least one of the signal data stored in the data sharing unit.

  According to the configuration of (4) above, the wireless communication device is configured to receive a plurality of signal data composed of signal data generated by each wireless communication device in response to reception of a wirelessly transmitted transmission request. Is transmitted wirelessly. That is, the signal data generated by each of the plurality of wireless communication devices is transmitted from the wireless communication device that has received the transmission request. As a result, a plurality of signal data can be transmitted in an aggregated form from one wireless communication device, and a plurality of signal data can be efficiently transmitted wirelessly.

(5) engaging Ru communication system with at least one embodiment of the present invention,
A plurality of wireless communication devices connected to a field device of a plant by signal lines and capable of wirelessly transmitting signal data obtained by converting a signal value of an input signal input from the signal line into data;
A collection device for collecting the signal data transmitted wirelessly from the wireless communication device, the collection device transmitting a transmission request for the signal data to at least one of the plurality of wireless communication devices; Prepared,
Each of the plurality of wireless communication devices belongs to one of a plurality of sharing groups for sharing the signal data generated by the plurality of wireless communication devices,
Each of the plurality of wireless communication devices, when receiving the transmission request, wirelessly transmits all the signal data shared by the sharing group to which the wireless communication device belongs to the collection device.

  According to the configuration of the above (5), the same effects as the above (3) to (4) are obtained.

(6) In some embodiments, in the configuration of (5) above,
The collection device transmits the transmission request to the representative wireless communication device defined for each of the plurality of sharing groups, and then the signal data corresponding to the transmission request even after a predetermined time has elapsed. If there is a representative wireless communication device that is not received, the other wireless communication devices that belong to the same shared group as the representative wireless communication device that does not receive the signal data corresponding to the transmission request Send a send request.

  According to the configuration of (6) above, the collecting device obtains signal data from other wireless communication devices belonging to the same shared group when the signal data cannot be obtained from the wireless communication device representing each shared group. To work. Thereby, signal data can be obtained reliably.

(7) In some embodiments, in the configuration of (5) above,
The collection device transmits the transmission request to all of the plurality of wireless communication devices.

  According to the configuration of (7) above, the collection device makes a transmission request to a plurality of wireless communication devices at the same time. For this reason, the signal data of the same content is received at the same time from one or more wireless communication devices that have received the transmission request. Therefore, although traffic increases, signal data can be obtained quickly (without delay).

(8) In some embodiments, in the configurations of (5) to (7) above,
The wireless communication devices in the same shared group are supplied with power from the same power source.

  According to the configuration of (8) above, wireless communication devices in the same sharing group share power. As a result, if wireless communication devices belonging to the same sharing group are connected using a composite cable composed of communication communication lines and power supply power lines via the inter-device communication unit, Without separately providing a communication line for data sharing, signal data can be shared between wireless communication devices that are communicably connected by a composite cable. In addition, management is facilitated, such as easy identification of wireless communication devices belonging to each shared group from the connection state between wireless communication devices.

  According to at least one embodiment of the present invention, a wireless communication device capable of relaying communication of a field device installed in a plant wirelessly with high reliability is provided.

The engagement Ru Comm system configuration to an embodiment of the present invention is a diagram schematically showing. It is a figure which shows schematically the structure of the radio | wireless communication apparatus which concerns on one Embodiment of this invention. Is a diagram schematically showing the engagement Ru Comm system configuration to an embodiment of the present invention, a plurality of wireless communication devices are grouped into a shared group. It is a figure for demonstrating the request | requirement system of the signal data which the collection apparatus which concerns on one Embodiment of this invention requests | requires, and a transmission request is transmitted to a representative radio | wireless communication apparatus for every share group. It is a figure for demonstrating the request | requirement system of the signal data which the collection apparatus which concerns on one Embodiment of this invention requests | requires, and a transmission request is transmitted to several radio | wireless communication apparatuses for every share group.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

Figure 1 is a diagram schematically illustrating an embodiment of the structure of the engagement Ru communication system 7 of the present invention. The communication system (hereinafter referred to as plant communication system 7 ) is a communication system for connecting the field device 8 installed in the plant and the plant control device 91 (hereinafter simply referred to as control device 91) in a communicable manner. The field device 8 measures, for example, temperature, flow rate, pressure, etc., and communicates various measurement devices 81 (sensors) that communicate measurement values with analog signals and switches such as limit switches, for example, with binary signals. Input devices such as digital input devices 83, control devices 82 such as control valves (valves) controlled by analog signals, electromagnetic valves (ON-OFF valves) controlled by binary signals of ON and OFF, etc. A plurality of field devices 8 are usually installed in the plant. The control device 91 is, for example, a distributed control system (DCS), which collects state information indicating the state of the plant such as various measurement values sent from various field devices 8, The plant is controlled through calculation and transmission of a control command (command value) for the field device 8.

  As shown in FIG. 1 (also in FIG. 3 described later), the plant communication system 7 includes at least one (a plurality in FIG. 1) wireless communication devices 1 connected to the field device 8, and the wireless communication devices. 1 and a collecting device 9 that collects the signal data D transmitted wirelessly from 1 and serves as the control device 91 described above. That is, in the plant communication system 7, a wireless communication section in which communication (relay) is performed wirelessly is provided on the communication path between the field device 8 and the control device 91. More specifically, the control device 91 is connected to a wireless device 93 capable of wireless communication with the wireless communication device 1 described above, and the wireless communication device 1 and the wireless device 93 on the control device 91 side are wirelessly connected. It becomes a communication section.

  In the embodiment shown in FIG. 1, the control device 91 is connected to a wireless device 93 via a wired network 72. The wireless device 93 is an access point, and communicates with the above wireless communication device 1 in accordance with various IEEE 802.11 standards. In some other embodiments, the control device 91 and the wireless device 93 on the control device 91 side may be directly connected by wire. A plurality of wireless devices 93 may be installed.

  Moreover, as shown in FIG. 1 (the same applies to FIG. 3 described later), the plant communication system 7 may further include a gateway device 92 (computer device). In the embodiment shown in FIG. 1, the wireless device 93 and the control device 91 are connected via a gateway device 92. The gateway device 92 stores a role of performing protocol conversion between the wireless device 93 side and the control device 91 side, and status information transmitted from the plurality of field devices 8 and sends them to the control device 91 collectively. It is a device that plays a role of reducing the load of 91.

  That is, in the embodiment shown in FIG. 1, the gateway device 92 and the control device 91 are connected by the control network 72c, and between the gateway device 92 and the control device 91 (control network 72c), and the gateway device 92, The communication protocol with the wireless device 93 (IP network 72l) is different. Therefore, the gateway device 92 performs protocol conversion to relay communication across both networks. In addition, the load on the control device 91 is reduced by causing the gateway device 92 to execute the protocol conversion function without using the control device 91 in this way. In the embodiment shown in FIG. 1, the gateway device 92 and the control device 91 are connected via a network device 94 (a hub in FIGS. 1 and 3). However, in some other embodiments, The gateway device 92 and the control device 91 may be directly connected via a communication line without going through the network device 94.

  However, the present invention is not limited to this embodiment. In some other embodiments, the gateway device 92 may not be provided by implementing the protocol conversion function in the control device 91. Further, the gateway device 92 may transmit state information data to the cloud 76 on the Internet by being connected to the Internet 75. In this way, it is possible to perform unified management of information on a plurality of plants, remote monitoring, operation support, predictive diagnosis, remote control, and the like based on data on the cloud. In this case, the collection device 9 may be the gateway device 92.

Next, the wireless communication device 1 will be described in detail with reference to FIG. FIG. 2 is a diagram schematically showing the configuration of the wireless communication device 1 according to an embodiment of the present invention.
The wireless communication device 1 is a device that is connected to a field device 8 of a plant through a signal line 71 and can wirelessly transmit signal data D obtained by converting the signal value of the input signal S from the field device 8 into data. As shown in FIG. 2, the wireless communication device 1 includes a signal input unit 21, a wireless communication unit 3, an inter-device communication unit 4, and a communication processing unit 5. These configurations are realized by an electronic circuit (electric circuit) or the like.
Hereinafter, each of the above-described functional units (circuits) included in the wireless communication device 1 will be described.

  The signal input unit 21 is configured to generate signal data D obtained by converting the signal value of the input signal S input from the signal line 71 connecting the field device 8 and the wireless communication device 1 into data. As shown in FIG. 2, the signal input unit 21 and the field device 8 are connected by a signal line 71 (wired). For example, when a field device 8 (such as a measuring instrument 81) that inputs an analog signal outputs a DC analog signal (input signal S) of 4 to 20 mA on which a measured value or the like is mapped to the signal line 71, an analog signal is output. When the signal is transmitted through the signal line 71, the input signal S is input to the signal input unit 21. The signal input unit 21 generates signal data D by converting the current value or voltage value input as the input signal S (analog signal) into digital data. Similarly, for example, when a digital input device 83 that performs input using a binary signal (High or Low, on or off, etc.) outputs a binary signal (input signal S) to the signal line 71, the binary signal is transmitted to the signal line. By transmitting 71, the input signal S is input to the signal input unit 21. The signal input unit 21 generates signal data D by converting the binary signal into digital data. The signal input unit 21 may be configured so that a plurality of field devices 8 can be connected.

  Note that a digital signal indicating additional information communicated simultaneously with the analog signal may be superimposed on the analog signal output from the field device 8. The additional information is, for example, device information such as an identification number of the field device 8 that has measured the measured value. In this case, the signal input unit 21 separates an analog signal (DC component) and a digital signal (frequency component) included in the input signal S, and includes signal data including both information communicated by the analog signal and the digital signal. D is generated. Such a communication method for simultaneously transmitting a plurality of signals is known as hybrid communication (smart communication) such as HART communication. In hybrid communication, a frequency indicating a bit value (0 or 1) is determined in advance, and a DC analog signal is modulated at a frequency corresponding to each bit value (0, 1) of a bit string constituting additional information. The digital signal is superimposed on the analog signal and transmitted.

  The wireless communication unit 3 is configured to be able to transmit (communicate) the signal data D wirelessly. The wireless communication unit 3 is connected to a communication processing unit 5 to be described later. When communication data including signal data D is input from the communication processing unit 5, an antenna (an omnidirectional whip antenna in FIG. 2) is connected. The communication data is placed on a frame for wireless communication, and the frame is transmitted wirelessly. The wireless communication unit 3 is also configured to be able to receive a frame transmitted by the wireless device 93 that is a communication partner of wireless communication. As a result, wireless two-way communication with the wireless device 93 that is the communication partner of the wireless communication becomes possible.

  The inter-device communication unit 4 is configured to be connected to another wireless communication device 1 by wire (communication cable 73). As shown in FIG. 2, the inter-device communication unit 4 is connected to a communication processing unit 5 described later. When communication data including signal data D is input from the communication processing unit 5, the inter-device communication unit 4 Communication data is transmitted to another wireless communication device 1 connected by the communication cable 73. Communication data transmitted from the inter-device communication unit 4 is transmitted through the communication cable 73 and received by the other wireless communication device 1.

  In the embodiment shown in FIG. 2, the inter-device communication unit 4 performs serial communication. More specifically, the inter-device communication unit 4 performs communication based on the RS-485 standard. Since RS-485 has a feature that it can connect a plurality of wireless communication devices 1 (multidrop connection) on the same communication line and has good real-time characteristics, data between a plurality of wireless communication devices 1 as will be described later. Suitable for sharing. In some other embodiments, the inter-device communication unit 4 may be configured to perform communication based on other serial communication standards such as the RS-422 standard. In some other embodiments, if communication between devices is possible, the device-to-device communication unit 4 performs communication based on other serial communication standards such as the RS-232 standard or communication standards other than serial communication. It may be configured.

  The communication processing unit 5 (CPU) inputs the signal data D to the wireless communication unit 3, so that the communication processing (wireless communication processing) of the signal data D via the wireless communication unit 3 or the inter-device communication unit 4 By inputting the signal data D, at least one of the communication processing (detour communication processing) of the signal data D via the inter-device communication unit 4 is executed. In the embodiment illustrated in FIG. 2, the wireless communication device 1 includes a memory (storage device m) such as a ROM or a RAM. Then, the CPU (processor) operates (data calculation, etc.) according to the instructions of the program loaded in the memory (main storage device), and the communication processing by the communication processing unit 5 is executed. The above wireless communication processing performs communication control necessary for E2E communication between the wireless communication device 1 and the collection device 9, such as TCP (UDP) / IP packet generation, TCP connection establishment, release, and retransmission control. May be included. On the other hand, the bypass communication processing may include processing such as setting of a destination address necessary for serial communication.

  For example, the communication processing unit 5 acquires information capable of evaluating the radio wave condition such as RSSI and various error rates, and executes the above-described wireless communication process when the radio wave condition is good based on the information. When it is determined that the radio wave condition is not good or when wireless communication is not possible, the bypass communication process may be executed. In the embodiment shown in FIG. 2, the wireless communication device 1 further includes a radio wave condition measuring unit 32 that measures (acquires) a radio wave condition such as RSSI, and the radio wave condition measured by the radio wave condition measuring unit 32 is a communication process. It is input to the part 5. Note that the wireless communication unit 3 and the radio wave state measurement unit 32 may be configured by one module. Further, as will be described later, the communication processing unit 5 may execute the above-described wireless communication process while the bypass communication process is executed regardless of the radio wave condition and the radio wave condition is good.

  In the embodiment shown in FIGS. 1 to 2, the plant communication system 7 includes a plurality of wireless communication devices 1 as shown in FIG. 1. And each of the some radio | wireless communication apparatus 1 is connected on the same communication line by connecting in series (row connection) with the communication cable 73 which connects the communication parts 4 between apparatuses (the figure mentioned later). 3). For this reason, the signal data D transmitted by any wireless communication device 1 from the inter-device communication unit 4 can be received by at least one other wireless communication device 1 connected to the same communication line. ing. Therefore, the signal data D generated by each wireless communication device 1 can be wirelessly transmitted from the wireless communication device 1 connected to the same communication line and capable of wireless communication to the collection device 9. .

  As shown in FIG. 2, the wireless communication device 1 having the above-described configuration outputs a signal (output signal So) such as an analog signal or a hybrid signal to the signal line 71 connected to the field device 8. The unit 22 (output circuit) may be further provided. Similarly, the wireless communication device 1 may include a signal output unit 22 that outputs a binary signal (output signal So) to the signal line 71 connected to the digital output device 84. In the embodiment shown in FIG. 2, the signal output unit 22 is connected to the field device 8 by a signal line 71. Then, when the communication processing unit 5 receives a command value transmitted from the control device 91, such as a damper control for the damper or a proportional valve control for the adjustment valve, or a request for additional information to the field device 8, the received content And a signal value obtained by determining a signal value of 4 to 20 mA or the like is input to the signal output unit 22. The signal output unit 22 outputs a DC analog signal, a hybrid signal, or a binary signal to the signal line so that the input signal value is transmitted to the signal line 71.

  In addition, in some embodiments, the wireless communication device 1 includes a power supply circuit 11 connected to an external power supply P (DC power supply) through an overvoltage protection circuit 11a and a reverse polarity connection protection circuit 11b as shown in FIG. And an interface for connecting to a maintenance personal computer (USB communication circuit 12a in FIG. 2), an interface for connecting to a personal computer for debugging (SCI communication circuit 12b in FIG. 2), and an error log and other wireless communication An interface that can attach and detach a storage medium for exchanging information between the device 1 and the outside (in FIG. 2, an SD card slot 13 to which an SD card can be attached and removed), and a measurement value display and an error code display. And a liquid crystal display 14 (LCD) that can perform the above-described operation. Except for the power supply circuit 11, it may be provided as necessary.

  These configurations are housed in the casing 10 of the wireless communication device 1 together with the signal input unit 21, the wireless communication unit 3, the inter-device communication unit 4, and the communication processing unit 5 described above.

  According to said structure, when transmitting the signal data D to communication destinations, such as the control apparatus 91 of a plant, for example, the radio | wireless communication apparatus 1 transmits by radio | wireless from an own machine, and other radio | wireless connected. It is configured to be able to transmit via the communication device 1. Therefore, for example, when the surrounding radio wave condition is good, the signal data D is transmitted wirelessly from the own device, and when the radio wave condition is bad, other wireless communication devices in which the surrounding radio wave condition is good. It becomes possible to transmit the signal data D via 1. Thereby, it is possible to more reliably perform communication of the signal data D from the wireless communication device 1 to the communication destination.

  In some embodiments, the above-described wireless communication device 1 is generated by the other wireless communication device 1 that is received via the signal data D generated by the signal input unit 21 and the inter-device communication unit 4. A data sharing unit 6 that stores the signal data D may be further provided. That is, the communication processing unit 5 transmits the signal data D to the other wireless communication device 1 via the inter-device communication unit 4 by executing at least the bypass communication processing. That is, the communication processing unit 5 communicates the signal data D via the inter-device communication unit 4 regardless of the radio wave conditions around the own device in order to share the signal data D among the plurality of wireless communication devices 1. .

  In the embodiment shown in FIGS. 1 to 2, the signal data D transmitted by each wireless communication device 1 via the inter-device communication unit 4 is received by one or more other wireless communication devices 1. For this reason, the data sharing unit 6 of each wireless communication device 1 includes a plurality of signals composed of signal data D generated by itself and signal data D generated by one or more other wireless communication devices 1. Data D is stored.

  In this embodiment, in some embodiments, when the communication processing unit 5 described above receives a transmission request Rq of the signal data D (hereinafter simply referred to as a transmission request Rq) via the wireless communication unit 3, the wireless processing unit 5 described above. Communication processing may be executed and at least one signal data D stored in the data sharing unit 6 may be transmitted. In the embodiment shown in FIGS. 1 and 2, the transmission request Rq is transmitted from the collection device 9. Further, when each wireless communication device 1 receives the transmission request Rq, the signal data D generated by itself and stored in the data sharing unit 6 and the other wireless communication device 1 with respect to the transmission source. The generated signal data D is communicated together as communication data, and a plurality of signal data D is transmitted.

  That is, the signal data D generated by each of the plurality of wireless communication devices 1 is transmitted from the wireless communication device 1 that has received the transmission request Rq. As a result, a plurality of signal data D can be transmitted in a form aggregated from one wireless communication device 1, and a plurality of signal data D can be efficiently transmitted wirelessly. At this time, it is not necessary for the other wireless communication device 1 to transmit the same signal data D wirelessly, and wireless communication can be omitted, so that power consumption can be suppressed.

  However, the present invention is not limited to this embodiment. In some other embodiments, the communication processing unit 5 periodically transmits the signal data D to the collection device 9 when the signal data D is input from the signal input unit 21 or via the wireless communication unit 3. It may be configured as follows. At the transmission timing, the signal data D generated by the other device stored in the data sharing unit 6 may be transmitted together with the signal data D generated by the own device.

  The timing at which the field device 8 transmits the measurement value (outputs to the signal line 71) is not necessarily the same. Therefore, the communication processing unit 5 receives signal data that has not yet been communicated with the collection device 9 among the signal data D that has already been received from each field device 8 when the transmission request Rq is received or at any regular transmission timing. Wireless transmission processing is executed so that D is transmitted together. When the signal data D that can be communicated is deleted from the data sharing unit 6, the communication processing unit 5 transmits all the signal data D remaining in the data sharing unit 6 when the transmission request Rq is received. To do.

  According to the above configuration, the wireless communication device 1 transmits the signal data D generated by itself to the other wireless communication device 1, and receives and stores the signal data D generated by the other wireless communication device 1. (store. In other words, between the plurality of wireless communication devices 1, the signal data D generated by each wireless communication device 1 is communicated between the devices regardless of surrounding radio wave conditions, and the signal data D is shared with each other. Is done. In this way, as long as there is at least one wireless communication device having a good radio wave condition, the signal data D can be transmitted from the wireless communication device 1 to the communication destination in a timely manner. Therefore, the communication of the signal data D from the wireless communication device 1 to the communication destination can be reliably performed in real time.

  In some embodiments, the above-described wireless communication device 1 may further include a power supply unit that supplies driving power to the field device 8 via the signal line 71 connected to the field device 8. That is, the wireless communication device 1 has the function of a distributor (power supply device), and supplies power, such as a constant voltage, to the field device 8 connected by the signal line 71. For this reason, it is not necessary to separately connect a power source to the field device 8, so it is not necessary to provide the external power source P near the field device 8, and the installation of the field device 8 becomes easy. In the embodiment shown in FIG. 2, the power supply unit 24 is connected to the signal input unit 21, so that power is supplied from the signal line 71 to the field device 8.

  According to the above configuration, the wireless communication device 1 supplies power to the field device 8 connected by the signal line. This eliminates the need for a power supply device (distributor) that is necessary in the prior art and supplies power from the control device 91 via the signal line 71, thereby reducing the cost of the plant.

Next, some embodiments on the assumption that the plant communication system 7 includes a plurality of wireless communication devices 1 will be described with reference to FIGS. Figure 3 is a diagram schematically illustrating an embodiment of the structure of the engagement Ru communication system 7 of the present invention, a plurality of wireless communication devices 1 are grouped into a shared group G. FIG. 4 is a diagram for explaining a request method of the signal data D requested by the collection device 9 according to an embodiment of the present invention. The transmission request Rq is transmitted to the representative wireless communication device 1 for each shared group G. Is done. FIG. 5 is a diagram for explaining a request method for the signal data D requested by the collection device 9 according to an embodiment of the present invention. The transmission request Rq is a plurality of wireless communication devices 1 for each sharing group G. Sent to.

  In some embodiments, as shown in FIGS. 3 to 5, each of the plurality of wireless communication devices 1 included in the plant communication system 7 is grouped so as to belong to one of the plurality of shared groups G. Also good. The sharing group G is a group for sharing the signal data D generated by each of the plurality of wireless communication devices 1 within the group, and one or more wireless communication devices 1 belong to each sharing group G. The grouping of the plurality of wireless communication devices 1 may be any method.

  For example, in some embodiments, as shown in FIGS. 3 to 5, one sharing group G may be configured by one or more wireless communication devices 1 that share a power source (external power source P). In other words, the wireless communication devices 1 in the same sharing group G are supplied with power from the same power source, for example, the same outlet to which the power plug (not shown) of the wireless communication device 1 is connected. In the embodiment shown in FIGS. 3 to 5, a communication line for communication and power supply are used as the communication cable 73 for connecting the wireless communication devices 1 belonging to the same sharing group G via the inter-device communication unit 4. A composite cable composed of power lines is used. Thus, as shown in FIG. 3, a plurality of wireless communication devices 1 can be connected via the inter-device communication unit 4 without providing a communication cable 73 for communication via the inter-device communication unit 4 separately from the power line. Connected to the same power supply in a daisy chain. Therefore, by composing the sharing group G with one or more wireless communication devices 1 sharing the same power source, they are communicably connected with a composite cable without separately providing a communication line for sharing the signal data D. The signal data D can be shared between the wireless communication devices 1. In addition, management is facilitated, for example, the wireless communication devices 1 belonging to each sharing group G can be easily identified from the connection state between the wireless communication devices 1.

  In the embodiment shown in FIGS. 3 to 5, the first shared group G1 is configured by the four wireless communication devices 1 (1a to 1d) connected to the first power source DC1, and is connected to the second power source DC2. A second sharing group G2 is configured by the three wireless communication devices 1 (1e to 1g). Therefore, the data sharing unit 6 of each wireless communication device 1 belonging to the first sharing group G1 stores the signal data D (Da to Dd) generated by each of the four wireless communication devices 1 (1a to 1d). In the data sharing unit 6 of each wireless communication device 1 belonging to the two sharing group G2, signal data D (De to Dg) generated by each of the three wireless communication devices 1 (1e to 1g) is stored. In some other embodiments, a communication cable 73 (composite cable) is further provided between the first wireless communication device 1a and the first power supply DC1 or between the fifth wireless communication device 1e and the second power supply DC2. The wireless communication devices 1 in the sharing group G may be connected in a ring shape via the power source DC. In this case, even if any communication cable 73 (composite cable) is disconnected in the shared group G, power is continuously supplied to all the wireless communication devices 1 in the shared group G. be able to.

  In the present embodiment, the collection device 9 (the gateway device 92 in FIG. 3) transmits a transmission request Rq to at least one of the plurality of wireless communication devices 1. When each of the plurality of wireless communication devices 1 receives the transmission request Rq, the wireless communication devices 1 wirelessly transmit all the signal data D shared by the shared group G to which the wireless communication device 1 belongs to the collection device 9. As described above, all the signal data D may be all the signal data D for which communication to the collection device 9 has not been completed.

  More specifically, in some embodiments, as illustrated in FIG. 4, the collection device 9 sends the above transmission request Rq to the representative wireless communication device 1 defined for each of the plurality of shared groups G. If there is a representative wireless communication device 1 that does not receive the signal data D corresponding to the transmission request Rq even after a predetermined time (timeout time) has elapsed after the transmission, the signal data corresponding to the transmission request Rq The transmission request Rq may be transmitted to another wireless communication device 1 belonging to the same sharing group G as the representative wireless communication device 1 from which D is not received. The number of the wireless communication devices 1 as representatives may be one or more for each sharing group G. In the embodiment shown in FIG. 4, the representative wireless communication device 1 to which the collection device 9 transmits the transmission request Rq is the first wireless communication device 1a in the first sharing group G1, and the fifth wireless in the second sharing group G2. It is the communication device 1e.

  Therefore, as shown in FIG. 4 (a), during normal times when no abnormality such as a communication failure or a failure of the wireless communication device 1 has occurred, the collection device 9 periodically contacts the first wireless communication device 1a, for example. By transmitting the transmission request Rq, the signal data D (D1 to D4) generated by each of the first wireless communication device 1a to the fourth wireless communication device 1d transmitted in response from the first wireless communication device 1a is received. To do. In addition, the collection device 9 transmits a transmission request Rq to the fifth wireless communication device 1e, whereby each of the fifth wireless communication device 1e to the seventh wireless communication device 1g transmitted as a response from the fifth wireless communication device 1e. The signal data D (D5 to D7) generated by the above is received.

  Further, as shown in FIG. 4B, in the event of an abnormality, the collection device 9 causes other wireless devices belonging to the same sharing group G as the representative wireless communication device 1 that cannot obtain a response to the transmitted transmission request Rq. A transmission request Rq is transmitted to the communication device 1. The collection device 9 obtains the signal data D to be collected from the representative wireless communication device 1 instead of the other wireless communication device 1 by obtaining a response to the transmission request Rq from the other wireless communication device 1. be able to. In FIG. 4B, when a timeout of a response to the transmission request Rq to the first wireless communication device 1a representing the first sharing group G1 is detected, the transmission destination of the transmission request Rq is set to the same first sharing group G1. It is switched to the second wireless communication device 1b to which it belongs. Then, the collection device 9 transmits the transmission request Rq to the second wireless communication device 1b, thereby obtaining the same signal data D as the signal data D to be received from the first wireless communication device 1a from the second wireless communication device 1b. ing.

  According to the above configuration, the collection device 9 receives signals from other wireless communication devices 1 belonging to the same sharing group G when the signal data D cannot be obtained from the wireless communication devices 1 representing each sharing group G. Operates to obtain data D. Thereby, the signal data D can be obtained reliably.

  In some other embodiments, as illustrated in FIG. 5, the collection device 9 may transmit a transmission request Rq to all of the plurality of wireless communication devices 1. As shown in FIG. 5A, when the collection device 9 transmits a transmission request Rq to all the wireless communication devices 1, for example, a response to the transmission request Rq as in the fifth wireless communication device 1e in FIG. Even if there is a wireless communication device 1 that cannot be obtained, signals to be collected by obtaining the same signal data D from other wireless communication devices 1 (sixth wireless communication device 1f or seventh wireless communication device 1g) Data D can be obtained more reliably and quickly.

  According to said structure, the collection apparatus 9 performs transmission request | requirement Rq with respect to the some radio | wireless communication apparatus 1 at the same time. For this reason, the signal data D having the same content is received at the same time from one or more wireless communication devices 1 that have received the transmission request Rq. Therefore, although the traffic increases, the signal data D can be obtained quickly (without delay).

The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.
For example, in some embodiments, the collection device 9 may apply a technique similar to the transmission request Rq described above when transmitting an operation command for control. Specifically, an operation command may be transmitted to the representative (one or more) wireless communication devices 1 for one or a plurality of sharing groups G, or an operation command may be transmitted to all the wireless communication devices 1. good. At this time, if the operation command is shared by the inter-device communication unit 4 among the plurality of wireless communication devices 1, the collection device 9 allows the wireless communication device 1 to which the field device 8 to which the operation command is transmitted is directly connected. Even when wireless communication is not possible, the operation command can be delivered to the destination field device 8 in real time via another wireless communication device 1 capable of wireless communication.

DESCRIPTION OF SYMBOLS 1 Wireless communication apparatus m Memory | storage device 11 Power supply circuit 11a Overvoltage protection circuit 11b Reverse polarity connection protection circuit 12a USB communication circuit 12b SCI communication circuit 13 SD card slot 14 Liquid crystal display 21 Signal input part 22 Signal output part 24 Power supply part 3 Wireless Communication unit 32 Radio wave condition measurement unit 4 Inter-device communication unit 5 Communication processing unit 6 Data sharing unit 7 Plant communication system (communication system)
71 Signal line 72 Wired network 72c Control network 72l Network 73 Communication cable 75 Internet 76 Cloud 8 Field device 81 Measuring device 82 Control device 83 Digital input device 84 Digital output device 9 Collection device 91 Control device 92 Gateway device 93 Wireless device 94 Network device

S input signal So output signal D signal data DC1 first power source DC2 second power source G shared group G1 first shared group G2 second shared group Rq transmission request P external power source

Claims (7)

A wireless communication device connected to a field device of a plant via a signal line,
A signal input unit that generates signal data obtained by converting a signal value of an input signal input from the signal line;
A wireless communication unit for wirelessly transmitting the signal data;
An inter-device communication unit connected by wire to other wireless communication devices;
A plurality of communication processing units that perform at least one of the communication processing of the signal data via the wireless communication unit or the bypass communication processing of the signal data via the inter-device communication unit. A wireless communication device;
A collection device that is a control device or a gateway device that collects the signal data transmitted wirelessly from the wireless communication device, and directly and wirelessly with the wireless communication unit of each of the plurality of wireless communication devices A collection device that is wired to a wireless device that communicates, and that transmits the signal data transmission request to at least one of the plurality of wireless communication devices via the wireless device ;
Each of the plurality of wireless communication devices belongs to one of a plurality of sharing groups for sharing the signal data generated by the plurality of wireless communication devices,
Each of the plurality of wireless communication devices, when receiving the transmission request, wirelessly transmits all the signal data shared by the sharing group to which the wireless communication device belongs to the collection device. Communications system.   The communication system according to claim 1, wherein the wireless communication device further includes a power supply unit that supplies driving power to the field device via the signal line. The wireless communication device includes a data sharing unit that stores the signal data generated by the signal input unit and the signal data generated by the other wireless communication device that is received via the inter-device communication unit. And further,
The communication system according to claim 1, wherein the communication processing unit executes at least the bypass communication process.   When the communication processing unit receives the transmission request for the signal data via the wireless communication unit, the communication processing unit executes the wireless communication processing and transmits at least one signal data stored in the data sharing unit The communication system according to claim 3. The collection device transmits the transmission request to the representative wireless communication device defined for each of the plurality of sharing groups via the wireless device, and then transmits the transmission even after a predetermined time has elapsed. When there is a representative wireless communication device that does not receive the signal data according to the request, the other wireless device belongs to the same sharing group as the representative wireless communication device that does not receive the signal data according to the transmission request. The communication system according to any one of claims 1 to 4 , wherein the transmission request is transmitted to the wireless communication device via the wireless device . The communication system according to claim 1, wherein the collection device transmits the transmission request to all of the plurality of wireless communication devices via the wireless device .   The communication system according to claim 1, wherein the wireless communication devices in the same shared group are supplied with power from the same power source.

Images