JP2006338088A - Automatic meter reading system and program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic meter reading system, capable of enhancing reliability of communication only by improvement of a center device without changing a circuit terminal device. <P>SOLUTION: This system comprises the center device 1, a modem 10 connected to the center device 1 through an IP network 9, and the circuit terminal device 12 provided in opposition to the modem 10 and connected to a meter 11 of a consumer. The center device 1 includes a command confirmation part 3 determining whether a response telegram from the meter is a predetermined command or not; a response telegram determination part 6 determining whether the response telegram is received or not; and a retransmission request part 4 transmitting a retransmission request telegram to the meter when a telegram other than the predetermined command is determined in the command confirmation part 3, or when receipt of any response is determined in the response telegram determination part 6. According to this, even if data for the response telegram from the meter 11 is missed, the communication can be continued by transmitting the retransmission request from the retransmission request part 4 for enhancing reliability of communication. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automatic meter reading system for performing meter reading of the usage amount of gas, water, electricity, and the like and a program thereof.

  Conventionally, in homes, offices, factories, etc., automatic collection of data recorded in a meter for measuring usage of gas, water, electricity, etc. to a center device, which is a remote metering meter device, via a communication line such as a telephone Meter reading systems have become widespread, and for example, this automatic meter reading system connects a telephone line and a meter installed in each consumer with a communication line, and communicates with the center device and the meter via the telephone line. Is.

  However, in the case of such an automatic meter reading system, the center device and the meter are often connected via IP, such as a dry kappa or an IP phone. However, in the case of via IP, compared to conventional end-to-end communication using a telephone line, there are many cases where data cannot be normally communicated due to loss of data on the way due to congestion or the like.

  Therefore, conventionally, when a voice signal is transmitted in a packet network represented by an ATM (Asynchronous Transfer Mode) network or an IP (Internet Protocol) network, there is a data accumulation delay when assembling the packet. It becomes a factor of transmission delay between terminals (End-End) and one of the causes of deterioration of call quality. As a countermeasure for reducing the delay time, a technique is known in which short packets with a reduced amount of data per packet are assembled and multiplexed on a transmission line. The technology in the ATM network is described in detail in the standards I363.2 and I366.2 of ITU-T (International Telecommunications Union-Telecommunication).

For example, in assembling and disassembling a cell of an audio signal to be transmitted / received, a first cell assembling unit that converts an encoded audio signal obtained by encoding the audio signal into a cell without performing silence compression, and encoding A second cell assembling means for silently compressing a voice signal into a cell, a voice cell formed into a cell by the first cell assembling means according to a congestion state of the ATM communication network at the time of setting a call for the voice signal, and a second There is known an apparatus provided with switching means for transmitting any one of the voice cells cellized by the cell assembling means to the ATM network (see, for example, Patent Document 1).
JP-A-9-326802

  However, in the conventional configuration, if a short packet is assembled, the data accumulation delay at the time of packet assembly can be shortened, but a header is added to each packet whose number of transmissions per unit time has increased. Therefore, there is a big problem that the overhead increases and the line terminal apparatus must be improved.

  The present invention solves the above-described conventional problems, and provides an automatic meter-reading system and a program thereof that can improve the reliability of communication without changing the line terminal device only by improving the center device.

  In order to solve the above-described conventional problems, an automatic meter reading system and a program thereof according to the present invention are provided with a center device, a modem connected to the center device via an IP network, and a consumer that is provided opposite to the modem. A line terminal device connected to the meter, wherein the center device determines whether a response message from the meter is a predetermined command, and a response message presence determination unit that determines whether there is a response message And a retransmission request unit that sends a retransmission request message to the meter when the command confirmation unit determines that there is something other than a predetermined command, or when the response message presence / absence determination unit determines that there is some response.

  As a result, even if the response message from the meter is lost due to congestion, etc., or if there is no data in the middle, the existing request is sent by sending a retransmission request from the retransmission request unit to the line terminal device or meter. Communication can be continued without changing the terminal device and the meter, and communication is not interrupted. Therefore, communication reliability can be improved.

  The automatic meter-reading system and its program according to the present invention retransmits from the retransmission request unit to the line terminal device or the meter even when the data in the response message from the meter is lost or lost due to congestion or the like. By sending a request, communication can be continued without changing an existing line terminal device or meter, and communication is not interrupted. Therefore, communication reliability can be improved.

  According to a first aspect of the present invention, there is provided a center device, a modem connected to the center device via an IP network, and a line terminal device provided opposite to the modem and connected to a consumer meter. Is a command confirmation unit that determines whether the response message from the meter is a predetermined command, a response message presence / absence determination unit that determines whether there is a response message, or a response other than a predetermined command in the command confirmation unit, or a response If the telegram presence / absence determination unit determines that there has been some response, an automatic meter reading system that has a retransmission request unit that sends a retransmission request message to the meter will cause the response message from the meter to be lost due to congestion, etc. Even if there is no data in the middle, an existing line terminal device or mail can be sent by sending a retransmission request from the retransmission request unit to the line terminal device or meter. Can continue communication without changing the order in which communication is not interrupted midway, it is possible to improve the reliability of communication.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the center device includes a message length confirmation unit that determines the message length of an expected response message, instead of the response message presence / absence determination unit. If it is not a predetermined command, or if it is determined that the message length is not the message length expected by the message length confirmation unit, a retransmission request message is sent to the meter, so the probability of communication interruption due to congestion can be easily reduced by changing the center device. It is something that can be done.

  According to a third aspect of the invention, in particular, in the first aspect of the invention, the center device has a transmission message retransmission unit that sends the previous transmission message as it is instead of the retransmission request unit, thereby reducing the probability of communication interruption due to congestion of the center device. It can be easily reduced by change.

  According to a fourth aspect of the invention, in particular, in the first aspect of the invention, the center apparatus determines that the IP network is congested by having a time zone changing unit that responds by changing the time zone instead of the retransmission request unit. However, since the communication is attempted by changing the time zone, the probability of communication interruption due to congestion can be easily reduced by changing the center device.

  In particular, the fifth invention is a program for causing a computer to execute at least a part of the functions of the automatic meter reading system according to any one of the first to fourth inventions. It is possible to easily realize at least a part of the automatic meter reading system of the present invention by cooperating hardware resources such as devices, computers, and servers. In addition, by recording on a recording medium or distributing the program using a communication line, the program can be easily distributed / updated and installed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows an automatic meter reading system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the automatic meter reading system includes a center device 1, a modem 10 for converting analog connected to digital via an IP network 9, and a meter 11 of a consumer provided facing the modem 10. And a line terminal device 12 to be connected. Here, the IP network 9 includes those in which analog / digital conversion is performed by an exchange located between the line terminal apparatus 12 and the center apparatus 1 without the modem 10 in the house. The modem 10 and the line terminal device 12 and the meter 11 may be wired or wirelessly communicated.

  The center device 1 determines whether a response message from the meter 1 or a response message from the line terminal device 12 or the modem 10 is a predetermined command, and further determines whether there is a response message. When the response message presence / absence determination unit 6 and the command confirmation unit 3 are other than a predetermined command, or when the response message presence / absence determination unit 6 determines that there is some response, the retransmission request unit 4 sends a retransmission request message to the meter 11. And have.

  When the data received by the center apparatus 1 is determined, the data structure is “STX”, “data”, “ETX”, “BCC”, so that the command confirmation unit 3 waits until “ETX” data is received. If “BCC is confirmed after receiving ETX” and it is OK, it is determined that the received data is normal and transmission is continued. However, if it is a BCC error, the command confirmation unit 3 determines that the data is abnormal, and the retransmission request unit 4 The retransmission request message is transmitted to the line terminal device 12. The line terminal device 12 that has received the retransmission request message receives a retransmission request again because the data sent to the center device 1 has a data error in the middle. The same data as the previously transmitted data is sent to the center apparatus 1 again.

  However, if the packet is dropped due to congestion or data is lost due to congestion because it is via the IP network 9, it will not be possible to receive “ETX” and the end of the data will not be determined, and a timeout will occur without sending a retransmission request message. And communication is interrupted. In order to prevent this, if “ETX” cannot be received within a predetermined time after “STX” is received by the response message presence / absence determination unit 6, it is determined that the packet is lost due to congestion, and the retransmission request unit 4 sends a retransmission request message to the terminal. To avoid communication interruption.

  As described above, in this embodiment, even when a packet in the middle is lost due to congestion via the IP network 9, the probability of communication interruption can be easily reduced by changing the center device 1, so Automatic meter reading can be performed.

(Embodiment 2)
FIG. 2 shows an automatic meter reading system according to Embodiment 2 of the present invention. The same elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in the figure, the automatic meter reading system of the present embodiment has a message length confirmation unit 5 that determines the message length of an expected response message, instead of the response message presence / absence determination unit 6 of the first embodiment. is there. The message length confirmation unit 5 determines whether the response message to the message transmitted is the correct message length. If the message length expected within a predetermined time cannot be received, it is determined that the packet is lost due to congestion, and the line terminal device 12 is notified. A retransmission request message is transmitted from the retransmission request unit 4 to avoid communication interruption. In addition, the determination of the data received by the center apparatus 1 is the same as in the first embodiment.

  As described above, in the present embodiment, when the command confirmation unit 3 is not a predetermined command or when it is determined that the message length is not the expected message length by the message length confirmation unit 5, a retransmission request message is sent to the meter 11. Therefore, the probability of communication interruption due to congestion can be easily reduced by changing the center device 1.

(Embodiment 3)
FIG. 3 shows an automatic meter reading system according to Embodiment 3 of the present invention. The same elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in the figure, the automatic meter reading system according to the present embodiment includes a transmission message retransmission unit 7 that transmits the previous transmission message as it is, instead of the retransmission request unit 4 of the first embodiment. The transmission message retransmitting unit 7 determines that the packet has been lost due to congestion when “ETX” cannot be received within a predetermined period of time after receiving “STX” by the response message presence / absence determination unit 6, and sends a previous message to the line terminal device 12. Communication interruption is avoided by sending the same data as the sent data. In addition, the determination of the data received by the center apparatus 1 is the same as in the first embodiment.

  As described above, the present embodiment includes the transmission message retransmission unit 7 that transmits the previous transmission message as it is, and the probability of communication interruption due to congestion even when an intermediate packet is lost due to congestion via IP or the like. Can be easily reduced by changing the center device 1.

  Furthermore, since a retransmission request is not sent, the previous transmission message can be continuously sent without limitation on the number of transmissions, and the probability of communication interruption can be further reduced.

(Embodiment 4)
FIG. 4 shows an automatic meter reading system according to Embodiment 4 of the present invention. The same elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in the figure, the automatic meter reading system according to the present embodiment has a time zone changing unit 8 that responds by changing the time zone, instead of the retransmission request unit 4 of the first embodiment. In particular, in the vicinity of 22:00, communication may not be completed normally no matter how many times communication is performed. In order to prevent this, if “ETX” cannot be received within a predetermined time after “STX” is received by the response message presence / absence determination unit 6, it is determined that the packet is lost due to congestion, and the communication is intentionally interrupted. In a time zone in which a lot of congestion is likely to occur, communication is performed without changing the time zone.

  As described above, in the present embodiment, the time zone changing unit 8 is provided, and the time zone in which the IP network is determined to be congested is not communicated, and the communication is attempted by changing the time zone. The probability of communication interruption due to congestion can be easily reduced by changing the center device.

  The means described in the first to fourth embodiments are hardware resources such as a CPU (or microcomputer), a RAM, a ROM, a storage / recording device, an electric / information device including an I / O, a computer, a server, and the like. You may implement in the form of the program which cooperates. In the form of a program, new functions can be distributed / updated and installed easily by recording them on a recording medium such as magnetic media or optical media or distributing them using a communication line such as the Internet.

  As described above, the automatic meter-reading system and the program according to the present invention provide the response message from the meter to the line terminal device or the meter even when the data is lost or lost due to congestion or the like. By sending a retransmission request from the retransmission request unit, communication can be continued without changing the existing line terminal device or meter, and communication is not interrupted, so communication reliability can be improved. It can also be applied to other communication systems.

Block diagram of the automatic meter reading system in Embodiment 1 of the present invention Block diagram of an automatic meter reading system in Embodiment 2 of the present invention Block diagram of an automatic meter reading system in Embodiment 3 of the present invention The block diagram of the automatic meter-reading system in Embodiment 4 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Center apparatus 3 IP network 4 Retransmission request part 5 Message length confirmation part 6 Response message presence / absence determination part 7 Transmission message resending part 8 Time zone change part 10 Modem 11 Meter 12 Line terminal device

Claims (5)

A center device, a modem connected to the center device via an IP network, and a line terminal device provided opposite to the modem and connected to a consumer meter, the center device receiving a response message from the meter A command confirmation unit that determines whether or not there is a response message, a response message presence / absence determination unit that determines whether or not there is a response message, and a command confirmation unit other than a predetermined command, or a response message presence / absence determination unit An automatic meter reading system having a retransmission request unit that transmits a retransmission request message to the meter when it is determined that there is a response. 2. The automatic meter reading system according to claim 1, wherein the center device includes a message length confirmation unit that determines a message length of an expected response message, instead of the response message presence / absence determination unit. The automatic meter reading system according to claim 1, wherein the center device includes a transmission message retransmission unit that transmits the previous transmission message as it is instead of the retransmission request unit. The automatic meter reading system according to claim 1, wherein the center device includes a time zone changing unit that changes the time zone and responds instead of the retransmission request unit. The program for making a computer perform at least one part of the function in the automatic meter-reading system of any one of Claims 1-4.

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