JP4846386B2 - Communications system - Google Patents

Description

  The present invention relates to a communication system used in the field of telemetering such as collection of sales information of vending machines and the field of telematics such as distribution of traffic information to a moving body.

  In recent years, telemetering and telematics for collecting and distributing information via a wireless packet communication network have become widespread. Telemetering is a general term for a mechanism that reads the measured value of a measuring instrument using a communication line. In general, it is a term used not only for reading data but also for monitoring the operation of equipment and for remote control. . Representative examples of telemetering include vending machine sales management systems, gas / water usage management systems, unmanned parking management systems, etc. 1). Telematics means providing information services in real time by combining a communication system with a mobile body such as an automobile. A typical example of telematics is an in-vehicle information system that provides traffic information and navigation information in real time to a terminal installed in a car.

In such a field, a communication device for connecting to a wireless packet communication network in a remote place and a host device using the communication device are arranged. For example, in a sales management system of a vending machine, a control device that performs sales control and temperature control in a warehouse corresponds to a host device. Each upper apparatus connects to a predetermined network via a communication device periodically or at any time, and connects to a predetermined management computer via the network. Then, the host device connected to the management computer transmits various management target data.
JP 2003-51056 A

  In such a system, the radio wave condition of the communication device is important in order to perform stable communication between the host device and the management computer. However, in the conventional system, the communication device is often installed in the host device, or the communication device and the host device are often connected by a cable of about several meters. That is, communication devices are often installed near the host device. For this reason, it has not always been possible to install a communication device in a place where the radio wave condition is good. The radio wave condition changes according to weather conditions, the situation of surrounding buildings, the radio wave intensity and the antenna setting change by the carrier, and the like. Accordingly, the radio wave condition in the vicinity of the host device may deteriorate. However, in the conventional system, it is difficult to install a communication device in a place away from the host device.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a communication system in which communication devices can be arranged far from the host device.

In order to achieve the above object, in the present invention, a communication device which is a data communication device (DCE: Data Circuit-terminating Equipment) for network connection service and a data terminal device (DTE) that performs communication using the communication device. A communication device including a host device that is a data terminal equipment, wherein at least a part of a communication path between the host device and a communication device is formed by a power line and connected to the host device side of the power line. The data received from the power line modem is superimposed on the power line as data at the connection terminal for the communication device of the higher level apparatus and interposed between the power line modem of 1 and the higher level apparatus and the first power line modem. A first connection device for converting the signal for the connection terminal; a second power line modem connected to the communication device side of the power line; and the communication. Between the power supply and the second power line modem and superimposing the signal at the connection terminal for the host device of the communication equipment as data on the power line and converting the data received from the power line modem into the signal for the connection terminal The first connection device monitors the state of the control line at the connection terminal of the host device or the communication device, and detects the change in the state when the state of the control line is detected. When data is transmitted to the opposing second or first connecting device and status data is received from the opposing second or first connecting device, the control line of the connection terminal of the communication device or the host device is set based on the status data. We propose a control feature.

  According to the present invention, a host device that is a data terminal equipment (DTE: Data Terminal Equipment) and a communication equipment that is a data communication equipment (DCE: Data Circuit-terminating Equipment) are connected by a power line communication system. The freedom of installation location of communication equipment is improved. In other words, since the host device itself is usually supplied with power by the power line, the power line is laid near the host device. Therefore, it becomes possible to install the communication device in an area where communication is possible using the power line. In addition, since it is not necessary to newly lay a signal line between the host device and the communication device, this system can be constructed at low cost. Furthermore, since the power line is usually laid in the wall or under the floor, it is also preferable from the viewpoint of scenery.

Further, in the present application, in the communication system, asynchronous communication is performed between the first connection device and the host device, and between the second connection device and the communication device. Synchronous communication is performed between the first power line modem and between the second connection device and the second power line modem, and the first and second connection devices perform mutual conversion processing between synchronous communication and asynchronous communication, respectively. We propose something that is characterized by

  As described above, according to the present invention, since the host device and the communication device are connected by the power line communication system, the flexibility of the installation location of the communication device is improved. In other words, since the host device itself is usually supplied with power by the power line, the power line is laid near the host device. Therefore, it becomes possible to install the communication device in an area where communication is possible using the power line. In addition, since it is not necessary to newly lay a signal line between the host device and the communication device, this system can be constructed at low cost. Furthermore, since the power line is usually laid in the wall or under the floor, it is preferable from the viewpoint of landscape.

  A communication system according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a communication system used in a vending machine will be described. FIG. 1 is a configuration diagram of a communication system.

  As shown in FIG. 1, the communication system includes a control device 10 of a vending machine 1 that is a data terminal equipment (DTE) and a communication module that is a data communication equipment (DCE: Data Circuit-terminating Equipment). 20 establishes a communication path with the network 20. In this application, the said control apparatus 10 shall be called the high-order apparatus 10. FIG. The host device 10 is designed so that the communication module 20 can be connected. The host device 10 and the communication module 20 perform asynchronous communication conforming to the RS-232C communication standard. Conventionally, the cable length of the RS-232C cable that connects the host device 10 and the communication module 20 is limited, so that the installation location of the communication module 20 is limited to the vicinity of the host device 10. The present invention uses a power line in the communication path between the host device 10 and the communication module 20 in order to widen the installation area of the communication module 20. Hereinafter, the communication system will be described in detail.

  The host device 10 is connected to the first power line modem 40 via the first connection device 30. The communication module 20 is connected to the second power line modem 45 through the second connection device 35. The first power line modem 40 and the second power line modem 45 are communicably connected using the power line 50 as a communication medium. Here, the first connection device 30 and the second connection device 35 are the same device. The first power line modem 40 and the second power line modem 45 are also the same device.

  The power line modems 40 and 45 are devices that perform data communication by superimposing data on the power line 50, and correspond to data communication devices. The data terminal devices connected to the power line modems 40 and 45 are connection devices 30 and 35. The power line modems 40 and 45 perform synchronous communication with the data communication device.

  The connection devices 30 and 35 are devices that mediate between the host device 10 or the communication module 20 and the power line modems 40 and 45. As shown in FIG. 2, the connection devices 30 and 35 are connected to the interfaces 31 and 36 connected to the data communication device connection terminals of the host device 10 and the data terminal device connection terminals of the power line modems 40 and 45. Interface 32, 37 and relay control units 33, 38.

  The relay control units 33 and 38 include data buffers 33a and 38a that temporarily store data received from the host device 10 and the communication module 20, and control line state flags 33b that hold a change state of the control lines of the interfaces 31 and 36. 38b. When the relay control units 33 and 38 detect that the state of the control lines of the interfaces 31 and 36 has changed by an interrupt, the relay control units 33 and 38 update the control line state flags 33b and 38b to True.

  The relay control units 33 and 38 send the data transmitted by the host device 10 or the communication module 20 and the status data of the control lines of the interfaces 31 and 36 to the connection devices 35 and 30 via the power line modems 40 and 45, respectively. Send. Here, the state data of the control line is data representing the state of a predetermined control line of the interfaces 31 and 36, for example, data representing the state of a plurality of control lines as a bit string. The relay control units 33 and 38 relay the data received from the connection devices 35 and 30 via the power line modems 40 and 45 to the host device 10 or the communication module 20, and the received data is the status data of the control line. In this case, the control lines of the interfaces 31 and 36 are controlled based on the state data. In this way, the connection devices 30 and 35 tunnel the communication path between the higher-level device 10 and the communication module 20 using the power line communication system. The host device 10 and the communication module 20 are devices that perform asynchronous communication, while the power line modems 40 and 45 are devices that perform synchronous communication. Therefore, the relay control units 33 and 38 also have a function of mutually converting synchronous communication and asynchronous communication.

  The operation of the relay control units 33 and 38 will be described with reference to the flowchart of FIG. The relay control units 33 and 38 inquire of the power line modems 40 and 45 about the operating state (step S1). Implement (Steps S3 to S8). Specifically, the data type and data size of the received data are received from the power line modems 40 and 45 (step S3), and then the data is received (step S4). If the data relates to the status data of the control line (step S5), the control lines of the interfaces 31 and 36 are controlled based on the status data (step S6). Otherwise, the data is stored. Relay to the host device 10 or the communication module 20 (step S7). And the relay control parts 33 and 38 confirm completion of reception between the power line modems 40 and 45 (step S8).

  On the other hand, when the operation state of the power line modems 40 and 45 is the standby state and the control line state flags 33b and 38b are True (step S9), the control line states of the interfaces 31 and 36 are converted into data. It transmits to the connecting devices 35 and 30 which oppose (step S10). Then, confirmation of transmission completion is performed with respect to the power line modems 40 and 45 (step S11), and the control line state flags 33b and 38b are updated to False (step S12).

  On the other hand, when the operation state of the power line modems 40 and 45 is the standby state and data from the host device 10 or the communication module 20 is stored in the data buffers 38a and 38b (step S13), the data A transmission process is performed (steps S14 to S16). Specifically, the data type and data size of the transmission data are notified to the power line modems 40 and 45 (step S14), and then the data in the data buffers 38a and 38b are transmitted (step S15). Then, the relay control units 33 and 38 confirm the completion of transmission for the power line modems 40 and 45 (step S16).

  A communication sequence among the host device 10 or the communication module 20, the connection devices 30 and 35, and the power line modems 40 and 45 will be described with reference to the sequence diagrams of FIGS. Here, the case of transmission / reception of communication data between the host device 10 and the communication module 20 instead of the status data of the control line will be described. First, the case where the host device 10 or the communication module 20 receives data from the power line modems 40 and 45 will be described with reference to FIG.

  When the connection devices 30 and 35 send a status confirmation request to the power line modems 40 and 45 (step S21), the power line modems 40 and 45 notify that they are in a transmission request state (step S22). Next, when the connection devices 30 and 35 send a confirmation request for the data type and data size to the power line modems 40 and 45 (step S23), the power line modems 40 and 45 respond with the data type and data size of the transmission data. (Step S24). Next, when the connection devices 30 and 35 send a transmission start request to the power line modems 40 and 45 (step S25), the power line modems 40 and 45 start data transmission (step S26). The connection devices 30 and 35 relay the received data to the host device 10 or the communication module 20 (step S27). When the data communication is completed, the connection devices 30 and 35 notify the power line modems 40 and 45 of confirmation of reception completion (step S28). The processing ends when the power line modems 40 and 45 return responses to the connection devices 30 and 35 (step S29).

  Next, a case where the host device 10 or the communication module 20 transmits data to the power line modems 40 and 45 will be described with reference to FIG.

  When the connection devices 30 and 35 receive data from the host device 10 or the communication module 20 (step S31), the connection devices 30 and 35 send a status confirmation request to the power line modems 40 and 45 (step S32). When the power line modems 40 and 45 are notified that they are in a standby state (step S33). The connection devices 30 and 35 notify the power line modems 40 and 45 of the data type and data size of the transmission data (step S34). When the connection devices 30 and 35 receive a response from the power line modems 40 and 45 (step S35), the connection devices 30 and 35 start data transmission to the power line modems 40 and 45 (step S36). The connection devices 30 and 35 receive the responses from the power line modems 40 and 45 (step S37). When the data transmission is completed thereafter, the connection devices 30 and 35 notify the power line modems 40 and 45 of confirmation of transmission completion (step S38). The process ends when the power line modems 40 and 45 return responses to the connection devices 30 and 35 (step S39).

  According to the present embodiment, since the host device 10 and the communication module 20 are connected by the power line communication system, the flexibility of the installation location of the communication module 20 is improved. That is, normally, the host device 10 itself is supplied with power by the power line, so that a power line is laid in the vicinity of the host device 10. Therefore, it becomes possible to install the communication module 20 in an area where communication is possible using the power line. In addition, since it is not necessary to newly lay a signal line between the host device 10 and the communication module 20, the present system can be constructed at a low cost. Furthermore, since the power line is usually laid in the wall or under the floor, it is also preferable from the viewpoint of scenery.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this. For example, in the above embodiment, the communication module 20 is a data communication device that performs asynchronous communication with the data terminal device, and the power line modems 40 and 45 are data communication devices that perform synchronous communication with the data terminal device. However, the present invention can be implemented even when the communication module 20 and the power line modems 40 and 45 are all data communication devices that perform asynchronous communication with the data terminal device. In this case, the connection devices 30 and 35 do not need a conversion function between synchronous communication and asynchronous communication. Similarly, the present invention can be implemented even when the communication module 20 and the power line modems 40 and 45 are all data communication devices that perform synchronous communication with the data terminal device.

  In the above embodiment, the communication system used in the vending machine has been described. However, the present invention can be applied to other systems. For example, a flow rate monitoring system in a sewer system or a management system for an unmanned parking lot can be cited.

Configuration diagram of communication system Connection device configuration diagram Flowchart explaining operation of connection device Sequence diagram explaining the communication sequence Sequence diagram explaining the communication sequence

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vending machine, 10 ... Host apparatus, 20 ... Communication module, 30, 35 ... Connection apparatus, 31, 32, 36, 37 ... Interface, 33, 38 ... Relay control part, 40, 45 ... Power line modem, 50 ... Power lines

Claims (2)

Communication including a communication device that is a data communication device (DCE) for network connection service and a host device that is a data terminal device (DTE: Data Terminal Equipment) that performs communication using the communication device A system,
While forming at least part of the communication path between the host device and the communication device by a power line,
A first power line modem connected to the host device side of the power line;
A signal that is interposed between the host device and the first power line modem and that superimposes a signal at a connection terminal for communication equipment of the host device as data on the power line and that receives data from the power line modem is a signal for the connection terminal. A first connection device for converting to
A second power line modem connected to the communication device side of the power line;
A signal interposed between the communication device and the second power line modem and superimposing a signal at a connection terminal for a host device of the communication device as data on the power line and receiving data from the power line modem as a signal for the connection terminal and a second connecting device to convert to,
Each of the first and second connection devices monitors the state of the control line at the connection terminal of the host device or the communication device, and when a change in the state is detected, the state data of the control line is opposed to the second or first A communication system that transmits to a connection device and controls a control line of a connection terminal of a communication device or a higher-level device based on the state data when receiving state data from a second or first connection device that faces the connection device . Asynchronous communication between the first connection device and the host device, and between the second connection device and the communication device,
Synchronous communication between the first connection device and the first power line modem, and between the second connection device and the second power line modem,
It said first and communication system according to claim 1, wherein the second is the connection device, characterized in that for performing mutual conversion of synchronous communication and asynchronous communication, respectively.

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