JP3142255U - Wireless communication system - Google Patents

Abstract

Kind Code: A1 The present invention includes a parent device connected to a center device via a public communication line and a plurality of child devices wirelessly connected to the parent device, and a meter reading value connected to the child device is transmitted to the center device via the parent device. Provided is a wireless communication system for reducing communication costs of a public communication line in a transmitting wireless communication system.
Radio slave units 2-1 to 2-n transmit meter-reading values of respective meters 3-1 to 3-n to the radio master unit 1 at a preset date and time (procedures S3 to S5). ). The wireless master device 1 stores the received meter reading value in a buffer memory. When the preset meter reading period ends, the wireless master device 1 connects the public communication line with the center device 5 and collects the meter reading values from all the wireless slave devices 2-1 to 2-n. (Steps S7 and S8).
[Selection] Figure 4

Description

  The present invention relates to a wireless communication system suitable for use in a meter reading system that performs remote meter reading of the amount of gas, water, etc. used.

  There is a meter reading system using wireless communication as a system for performing remote meter reading of a meter reading value such as a gas meter installed in a general home. This meter-reading system includes a center device that controls various controls, a parent device connected to the center via a public communication line such as a telephone line, and a plurality of child devices connected to the parent device via a wireless line. And a meter device connected to each slave unit via a wired line (Patent Document 1).

  In this meter-reading system, when the master unit receives a meter-reading request message including the slave unit ID of the slave unit connected to the meter device to be metered from the center device, the master unit modulates the meter-reading request message with a predetermined modulation method. And send it to the slave unit as a wireless telegram signal. After receiving the wireless telegram signal, the slave unit demodulates the meter reading request message to determine whether or not it is the corresponding slave unit, and modulates the meter reading response message including the meter reading data by a predetermined modulation method. A sentence signal is sent to the main unit. After receiving the wireless telegram signal, the master unit demodulates the meter reading response message, and then transmits the demodulated meter reading response message to the center device via the telephone line.

  At this time, the telephone line between the parent device and the center device is maintained in a connected state from when the center device transmits a meter-reading request message to when it receives meter-reading response messages of all the child devices.

However, in the above meter reading system, since the connection state of the public communication line is maintained from the transmission of the meter reading request message to the reception of the meter reading response message of all the slave units, in particular, the telephone using the circuit switching method In the case of a network, there is a problem that a large amount of communication cost is generated due to a long communication time.
JP 2001-128256 A

  The present invention has been made to solve such a problem, and a master unit connected to the center apparatus by a public communication line is connected to each meter, and is connected to the master unit by a wireless line. In a wireless communication system that includes a plurality of slave units and transmits meter reading values of each meter from the slave unit to the center unit via the master unit, the communication cost is reduced by reducing the connection state maintenance time of the public communication line That is.

  The present invention comprises a master unit connected to a center device via a public communication line, and a plurality of slave units connected to the master unit via a wireless line, and a meter reading value of each meter. In a wireless communication system that transmits data from a machine to a center unit via a master unit, each slave unit has means for transmitting a meter reading value of each meter to the master unit within a predetermined period, and the master unit receives it within the period. A wireless communication system comprising: means for storing the measured meter reading value; and means for connecting a public communication line to the center device after the period has elapsed and transmitting all stored meter reading values collectively. is there.

  According to the present invention, the meter reading value of each meter is collected by the master unit within a predetermined period, and when the period has elapsed, the master unit and the center device are connected by a public communication line, and the meter reading value of the collected meter is collected. Are sent together and the public communication line is disconnected after the transmission is completed.

  According to the present invention, since the connection state of the public communication line is maintained only when the meter reading values are transmitted collectively, the meter reading request message is transmitted from the transmission of the meter reading request message. As compared with the conventional system that maintains the connection state until this time, the maintenance time of the connection state is greatly shortened, and as a result, the communication cost is reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a remote meter reading system using a wireless communication system according to an embodiment of the present invention. This remote meter-reading system includes a wireless master device 1, n wireless slave devices 2-1 to 2 -n under its control, and a center device 5.

  The wireless master device 1 and the center device 5 can perform data communication via a public communication line such as a PHS (Personal Handyphone System) line. The wireless master device 1 and the wireless slave devices 2-1 to 2-n can perform data communication by specific low power wireless. Each wireless slave unit 2-1 to 2-n has a data communication with a meter 3-1 to 3-n such as a gas meter and a detector 4-1 to 4-n such as a gas leak detector via a cable or the like. Is possible.

  FIG. 2 is a block diagram showing the configuration of the wireless master device 1. The wireless master device 1 includes a CPU 11, a ROM 12, a RAM 13, a timer 14, a public communication line transmission / reception circuit 15, and a specific low-power wireless transmission / reception circuit 16 each connected to the CPU 11.

  The CPU 11 controls the entire wireless master device. The ROM 12 stores programs and fixed data used when the CPU 11 executes various controls. The RAM 13 is a work area in which programs and data used when the CPU 11 executes various controls are temporarily stored. The timer 14 notifies the CPU 11 when the preset date and time comes. Here, a simultaneous meter reading period of the wireless master device 1, that is, the wireless master device 1 starts a meter reading of the meters 3-1 to 3-n connected to all the wireless slave devices 2-1 to 2-n. Notify when the date and time and the date and time to end.

  The public communication line transmission / reception circuit 15 has a public communication line control (connection, disconnection, etc.) function with the center device 5 and a function of transmitting / receiving data during line connection. The specific low power wireless transmission / reception circuit 16 has control (connection, disconnection, etc.) of the specific low power wireless line between the wireless slave units 2-1 to 2-n and a function of transmitting / receiving data during the line connection Have

  FIG. 3 is a block diagram showing the configuration of the wireless slave units 2-1 to 2-n. The configuration of each of the wireless slave units 2-1 to 2-n is the same. The wireless slave units 2-1 to 2-n include a CPU 21, a ROM 22, a RAM 23, a timer 24, a specific low-power wireless transmission / reception circuit 25, and a wired communication circuit 26, each connected to the CPU 21. A meter and a detector are connected to the wired communication circuit 26.

  The CPU 21 controls the entire wireless slave unit. The ROM 22 stores programs and fixed data used when the CPU 21 executes various controls. The RAM 23 is a work area in which programs and data used when the CPU 21 executes various controls are temporarily stored. The timer 24 is notified to the CPU 21 when a preset date and time is reached. Here, the meter reading notification date and time set during the above-described simultaneous meter reading period, that is, the meter reading values of the meters 3-1 to 3-n to which the wireless slave units 2-1 to 2-n are connected respectively are wirelessly transmitted. Notify when the date and time to be transmitted to the main unit 1 is reached.

  The specific low power wireless transmission / reception circuit 25 has control (connection, disconnection, etc.) of a specific low power wireless line with the wireless master device 1 and also has a function of transmitting and receiving data while the line is connected. The wired communication circuit 26 has control (connection, disconnection, etc.) of a wired communication line between the meter and the detector, and also has a function of transmitting and receiving data while the line is connected.

The operation of the remote meter reading system having the above configuration will be described with reference to the sequence diagram of FIG.
First, the meter reading notification date and time is set in the timers 24 of the wireless slave devices 2-1 to 2-n, that is, the wireless slave devices subordinate to the wireless master device 1 (step S1). At this time, the meter reading notification date and time set in the timer 14 of each of the wireless slave devices 2-1 to 2-n is slightly shifted from each other so that the transmission operation to the wireless master device 1 does not compete.

  Next, a simultaneous meter reading period (meter reading start date and time, meter reading end date and time) is set in the timer 14 of the wireless master device 1 (step S2). This simultaneous meter reading period includes the meter reading notification date and time set for all the wireless slave units 2-1 to 2-n, in other words, covers the earliest meter reading notification date and time from the earliest meter reading notification date and time. Set to.

  The timer setting of the wireless slave unit and the wireless master unit may be set manually by an operator by connecting a setting device to each wireless slave unit and the master unit, or by wireless communication from the center device 5. It may be set.

  In the wireless slave units 2-1 to 2-n, when the meter reading notification date and time set in each timer 24 arrives, the timer 24 notifies the CPU 21. Upon receiving this notification, the CPU 21 transmits a meter reading value request message to the meters 3-1 to 3-n via the wired communication circuit 26 (step S3). The meters 3-1 to 3-n that have received the meter reading value request message transmit the meter reading value response message to the wireless slave units 2-1 to 2-n (step S4).

  The wireless slave devices 2-1 to 2-n report the received meter reading value response message to the wireless master device 1 (step S5). As described above, when the earliest meter reading notification date and time has arrived, the wireless master device 1 has started a simultaneous meter reading period, so the wireless master device 1 sends a meter reading notification from each of the wireless slave devices 2-1 to 2-n. Messages can be received in order from the earliest date of meter reading. Each time the wireless master device 1 receives a meter-reading notification message from each of the wireless slave devices 2-1 to 2-n, it returns a communication end message (step S6). The meter reading value included in the received meter reading notification message is stored in the RAM 13 (buffer memory).

  In the wireless master device 1, when the simultaneous meter reading period set in the timer 14 ends, the public communication line transmission / reception circuit 15 performs line connection to the center device 5 under the control of the CPU 11 notified from the timer 14 (procedure) S7). When connected to the center device 5, the CPU 11 reads out all the meter reading values stored in the RAM 13, and collectively transmits them to the center device 5 as message data of a meter reading notification message (step S8).

  The center device 5 that has received the meter reading notification message returns a reception completion message to the wireless master device 1 (step S9). After receiving the reception completion message, the wireless master device 1 disconnects the public communication line with the center device 5 (step S10).

  As described above, according to the meter-reading system of the present embodiment, the public communication line between the wireless master device 1 and the center device 5 maintains the connection state because the wireless master device 1 is connected to the wireless slave device 2- It is only the period during which the meter reading values of the meters 3-1 to 3-n connected to 1 to 2-n are transmitted together. Therefore, compared with the conventional system that maintains the connection state from the transmission of the meter reading request message to the reception of the meter reading response message of all the slave units, the communication maintenance time is significantly reduced by significantly reducing the connection maintenance time. Significant reduction is possible.

  In the above embodiment, when the meter reading notification date / time is reached, the wireless slave device voluntarily acquires the meter reading value of the meter and transmits it to the wireless master device, but when the simultaneous meter reading start date / time is reached. Next, the wireless master unit sequentially requests meter reading values from each wireless slave unit, and each wireless slave unit acquires the meter reading value and sends it to the wireless master unit in response to the request of the wireless master unit. You may comprise.

It is a figure which shows the remote meter-reading system using the radio | wireless communications system of embodiment of this invention. It is a block diagram which shows the structure of the wireless main | base station in the radio | wireless communications system of embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless subunit | mobile_unit in the radio | wireless communications system of embodiment of this invention. It is a sequence diagram which shows operation | movement of the remote meter-reading system of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wireless main unit, 2-1 to 2-n ... Wireless sub unit, 3-1 to 3-n ... Meter, 5 ... Center apparatus, 11, 21 ... CPU, 13 , 23 ... RAM, 14, 24 ... timer, 15 ... public communication line transmission / reception circuit, 16, 25 ... specific low-power wireless transmission / reception circuit.

Claims (2)

A master unit connected to the center device via a public communication line and a plurality of slave units each connected to the master unit via a wireless line, and the meter reading value of each meter from the slave unit to the master unit In a wireless communication system for transmitting to a center device via
Each slave unit has transmission means for transmitting the meter reading value of each meter to the master unit within a predetermined period. The master unit stores storage means for storing the meter reading value received within the period, and the center after the period has elapsed. A wireless communication system comprising: means for connecting a public communication line to the apparatus; and transmission means for collectively transmitting all stored meter reading values to the center apparatus. The wireless communication system according to claim 1, wherein
The wireless communication system, wherein the transmission means of each slave unit transmits at different times within the period.

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