JP2008275457A - Gas meter and gas leakage alarm device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas meter and a gas leakage alarm device enabling automatic switching by automatically recognizing whether or not the connected counterpart can be communicated by an electronic message system. <P>SOLUTION: In a gas meter 1, a signal for detecting non-connection is output to a gas leakage alarm device 2. If there is a response, a connected gas leakage alarm device 2 recognizes that it can be communicated by an electronic message system, and performs subsequent communications by the electronic message system. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas meter and a gas leak alarm capable of communicating information such as a gas leak alarm and a gas cutoff.

  Conventionally, communication performed between a gas meter and a gas leak alarm is performed by an ON / OFF method or a pulse method. These methods convey the information by giving meaning to the ON level and OFF level of the signal line, or changing the pulse length and the number of pulses. It was difficult to convey more information such as usage.

Some gas meters can transmit and receive data to and from a monitoring center through a public telephone line for the purpose of centralized monitoring. For example, the communication is performed by a telegram system in which 0 and 1 are combined as in the gas meter with an alarm device described in Patent Document 1. Since the telegram system can give meaning to a combination of 0 and 1 having a predetermined number of bits, the amount of information that can be easily transmitted can be increased.
JP 2001-236588 A

  However, when the communication between the gas meter and the gas leak alarm device is carried out with the telegram method, both must be compatible with the telegram method, but it is rare that the gas meter and the gas leak alarm device are exchanged at the same time. Therefore, both the gas meter and the gas leak alarm must be compatible with the conventional ON / OFF method, pulse method, and message method. The pulse method is upwardly compatible with the ON / OFF method, but the message method is not compatible with the ON / OFF method or the pulse method. Don't be.

  Moreover, it is preferable that the correspondence to each communication method described above is realized by the same hardware in order to avoid an increase in cost.

  Accordingly, the present invention provides a gas meter and a gas leak alarm that can automatically switch and automatically switch whether or not the connected partner can communicate by telegram method, paying attention to the above problems. The task is to do.

  The invention according to claim 1, which has been made to solve the above-described problem, is a gas meter including a communication unit that is connected to a gas leak alarm and outputs a signal for detecting disconnection to the gas leak alarm. The communication means determines whether or not a response signal from the gas leak alarm device has been input after outputting a signal for detecting the disconnection, and determines that the response signal has been input. When the subsequent communication with the gas leak alarm is performed by the method and it is determined that the response signal is not input, the subsequent communication with the gas leak alarm is performed by the pulse method or the ON / OFF method. It is said.

  The invention according to claim 2 is a gas leak alarm device comprising a communication means that is connected to a gas meter and outputs a response signal to the gas meter when a signal for detecting non-connection from the gas meter is inputted. The communication means determines whether or not a reply message to the response signal is input from the gas meter, and if it is determined that the reply message is input from the gas meter, communicates with the gas meter in a message system, When it is determined that the reply message is not input from the gas meter, communication with the gas meter is performed by a pulse method or an ON / OFF method.

  As described above, according to the first aspect of the present invention, it is determined whether or not a response signal to the signal for detecting the disconnection output from the meter communication means to the gas leak alarm is input from the gas leak alarm. By switching the telegram method and the pulse method or ON / OFF method, the communication method can be automatically recognized and automatically switched by outputting a signal to detect disconnection. Can do.

  According to the second aspect of the invention, the alarm communication means determines whether or not a reply message is input after outputting a response signal to the signal for detecting the unconnected input from the gas meter. Since switching between the pulse method and the ON / OFF method can be performed, a communication-enabled method can be automatically recognized and switched automatically when a signal for detecting unconnection is input.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a gas meter and a gas leak alarm according to an embodiment of the present invention. FIG. 2 is a flowchart showing an operation of discriminating the communication method of the gas leak alarm in the gas meter shown in FIG. FIG. 3 is a waveform diagram of the unconnected detection signal. FIG. 4 is a flowchart showing an operation of discriminating the communication method of the gas meter in the gas leak alarm shown in FIG. FIG. 5 is an example of a telegram configuration used between the gas meter and the gas leak alarm shown in FIG. FIG. 6 is an example of a communication procedure using a telegram used between the gas meter and the gas leak alarm shown in FIG.

  A gas meter 1 according to an embodiment of the present invention includes a μCOM 11, a measurement unit 12, a display unit 13, a shutoff valve 14, a center communication unit 15, a return switch 16, and an interface unit 17.

  The μCOM 11 as a meter communication means includes a CPU (Central Processing Unit) 11a that performs various processes and controls in accordance with a predetermined program, a ROM 11b that is a read-only memory that stores a program for processing performed by the CPU 11a, and the like. The microcomputer includes a RAM 11c, which is a readable / writable memory that stores various data and has an area necessary for processing operations of the CPU 11a. The μCOM 11 performs overall control of the gas meter 1 such as integration and blocking of the gas flow rate and communication control with the gas leak alarm 2.

  The measuring unit 12 measures the flow rate of the gas flowing through the gas flow path and is composed of a flow rate sensor such as a membrane type, ultrasonic type sensor or flow sensor, and outputs the measurement result to the μCOM 11.

  The display unit 13 is a liquid crystal display (LCD) or the like, and displays various information such as an integrated value of gas usage and an alarm under the control of the μCOM 11.

  The shutoff valve 14 is a shutoff valve for shutting off the supply of gas to the gas appliance connected to the gas meter 1, and a signal indicating a gas leak notification from the gas leak alarm 2 or a shutoff event in the gas meter 1. Detection (blocking the total flow rate that shuts off when the gas flow exceeds the total consumption of the connected gas appliances, and blocking the usage time when the connected gas appliances are used abnormally for a long time Etc.), the μCOM 11 instructs to shut off.

  The center communication unit 15 uses an NCU (Network Control Unit), is controlled by the μCOM 11, and can communicate with a management center of a gas dealer through a public line such as a telephone line.

  The return switch 16 is turned on when a return button (not shown) is pressed, and outputs a return signal for opening the shut-off valve 14 to the μCOM 11.

  The interface unit 17 serving as a meter communication unit generates and outputs a signal to be output to the gas leak alarm device 2 according to an instruction from the μCOM 11 and inputs a signal input from the gas leak alarm device 2 to the μCOM 11.

  The gas leak alarm device 2 according to an embodiment of the present invention includes a μCOM 21, a gas sensor 22, an alarm unit 23, and an interface unit 24.

  The μCOM 21 as an alarm communication means includes a CPU (Central Processing Unit) 21a that performs various processes and controls in accordance with a predetermined program, and a ROM 21b that is a read-only memory that stores a program for processes performed by the CPU 21a. The microcomputer includes a RAM 21c, which is a readable / writable memory that stores various data and has an area necessary for processing operations of the CPU 21a. The μCOM 21 performs overall control of the gas leak alarm 2 such as detection of gas leak and determination of whether or not to issue an alarm, and communication control with the gas meter 1.

  The gas sensor 22 is configured by a semiconductor sensor whose resistance value changes due to a reaction with a combustible gas such as carbon monoxide (hereinafter referred to as CO) or methane, and the resistance value according to the concentration of the combustible gas. Is converted into a voltage and output to the μCOM 21.

  The alarm unit 23 includes a speaker, an indicator, a display device, and the like (not shown) for notifying an alarm when a gas leak occurs by voice or the like according to an instruction from the μCOM 21 or a voice based on a signal received from the gas meter 1.

  The interface unit 24 as an alarm communication means generates and outputs a signal to be output to the gas meter 1 according to an instruction from the μCOM 21, and detects or inputs a signal input from the gas meter 1 to the μCOM 21.

  In the gas meter 1 and the gas leak alarm 2 configured as described above, the interface unit 17 of the gas meter 1 and the interface unit 24 of the gas leak alarm 2 are connected via a connection line 30. Information is transmitted / received using a communication method recognized by each other.

  Next, the operation of determining the communication method of the gas leak alarm 2 in the gas meter 1 having the above-described configuration will be described with reference to the flowchart shown in FIG. The flowchart of FIG. 2 is executed by the CPU 11a of the μCOM 11.

  First, in step S11, an unconnected detection signal as a signal for detecting unconnected is output to the gas leak alarm 2, and the process proceeds to step S12. The unconnected detection signal is a signal output from the gas meter 1 to detect that the gas leak alarm 2 is not connected to the gas meter 1, and predetermined waveform conditions and the like are defined in advance. In this embodiment, the unconnected detection signal receives an instruction from the μCOM 11 and the interface unit 17 outputs a pulse having a width of 5 ms (millisecond) once as shown in FIG.

  Next, in step S12, it is determined whether or not a response signal to the unconnected detection signal output in step S11 is input from the gas leak alarm device 2 via the interface unit 17, and if it is input (in the case of Y). In step S13, if no input is made (in the case of N), the gas leak alarm device 2 recognizes that it is an ON / OFF method or a pulse method, and thereafter performs communication by an ON / OFF method or a pulse method. Whether or not a response signal has been input is determined by whether or not a response message or response pulse in a predetermined format has been input within a predetermined time.

  Next, in step S13, since there was a response signal to the unconnected detection signal, the gas leak alarm device 2 recognizes that it is a telegram system, and a gas leak alarm device with a reply message indicating that the response signal was recognized. 2 to communicate with the telegram method. The above steps are performed by the μCOM 11, and input / output of each signal is performed via the interface unit 17, and the μCOM 11 and the interface unit 17 correspond to the meter communication means in the claims.

  Next, the operation of determining the communication method of the gas meter 1 in the gas leak alarm device 2 having the above-described configuration will be described with reference to the flowchart shown in FIG. The flowchart of FIG. 4 is executed by the CPU 21a of the μCOM 21.

  First, in step S21, if it is detected by detecting whether or not an unconnected detection signal input from the gas meter 1 is detected, the process proceeds to step S22. If not detected, the process waits in this step.

  Next, in step S22, a response message (or response pulse) as a response signal is output to the gas meter 1 in response to the input of the unconnected detection signal, and the process proceeds to step S23.

  Next, in step S23, it is determined whether or not a reply message for the response message output in step S22 has been input from the gas meter 1, and if it has been input, the gas meter 1 recognizes that it is a message method and thereafter uses the message method. If communication is not performed and the gas meter 1 is not input, the gas meter 1 recognizes that it is an ON / OFF method or a pulse method, and thereafter performs communication using an ON / OFF method or a pulse method. Whether or not a reply message has been input is determined based on whether or not a reply message in a predetermined format has been input within a predetermined time. Each of the above steps is performed by the μCOM 21 and input / output of each signal is performed via the interface unit 24. Therefore, the μCOM 21 and the interface unit 24 correspond to alarm device communication means in the claims.

  The message used in this embodiment is composed of characters as shown in FIG. One character is composed of a combination of 0 and 1 of 5 bits. The telegram is composed of a set of characters starting with a communication control character STX and ending with ETX. FIGS. 5A to 5C show a telegram configuration used when various data are acquired from the gas leak alarm 2 to the gas meter 1. FIG. 5D shows a telegram configuration used when various data are transmitted from the gas meter 1 to the gas leak alarm 2.

  FIG. 6 shows an example of a communication method using a telegram method according to this embodiment. FIG. 6A shows a procedure in the case of transmitting a cause of interruption from the gas meter 1 to the gas leak alarm 2. First, a switch SW2 (not shown) provided in the interface unit 17 of the gas meter 1 is turned off, and a mark to be given before the telegram is output for a predetermined time (T1). Next, a message including the cause of interruption is output. Then, the switch SW2 is turned on and a space to be added after the telegram is output for a predetermined time (T2). On the gas leak alarm 2 side, a switch SW3 (not shown) provided in the interface unit 24 is turned on, and after detecting the space input from the gas meter 1, the SW3 is turned off for a predetermined time (Td).

  FIG. 6B shows a procedure when the gas meter 1 transmits a message in response to the message from the gas leak alarm 2. First, a switch SW3 (not shown) provided in the interface unit 24 of the gas leak alarm 2 is turned on to output a mark to be given before the message for a predetermined time (Ta). Next, a message containing information such as the occurrence of gas leakage is output. Then, the switch SW3 is turned off and a space to be added after the telegram is output for a predetermined time (Tb), and then the switch SW3 is kept on. On the gas meter 1 side, a switch SW2 (not shown) provided in the interface unit 17 is turned off, and a mark to be given before a telegram after the gas leak alarm device 2 outputs a space is output for a predetermined time (T1). To do. Next, a message including data indicating that the gas leak occurrence information has been received is output. Then, the switch SW2 is turned on and a space to be added after the telegram is output for a predetermined time (T2). On the gas leak alarm 2 side again, after detecting the space input from the gas meter 1, the SW3 is turned OFF for a predetermined time (Td).

  According to the gas meter 1 described above, when determining the communication method of the gas leak alarm device 2, it is determined whether or not communication can be performed by a telegram method depending on whether or not there is a response to the output of the unconnected detection signal. By outputting a signal for detecting an unconnected state, a communicable system can be automatically recognized and switched automatically.

  In addition, according to the gas leak alarm device 2 described above, when determining the communication method of the gas meter 1, it is determined whether or not communication can be performed by a telegram method depending on whether or not there is a response to the response to the unconnected detection signal. By inputting a signal for detecting unconnection, a communicable method can be automatically recognized and switched automatically.

  The unconnected detection signal may be periodically output in consideration of a case where the gas meter 1 or the gas leak alarm 2 is replaced or a power failure, and the communication method may be determined. For example, when the gas meter 1 or the gas leak alarm device 2 is replaced, the communication method may be determined by outputting for a certain period after the shipment mode is canceled or after a power is turned on.

  In the above-described embodiment, the connection line 30 between the gas meter 1 and the gas leak alarm 2 is wired, but may be wireless.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

It is a block diagram showing a gas meter and a gas leak alarm concerning one embodiment of the present invention. It is the flowchart which showed the operation | movement which discriminate | determines the communication system of a gas leak alarm device in the gas meter shown by FIG. It is a wave form diagram of an unconnected detection signal. It is the flowchart which showed the operation | movement which discriminate | determines the communication system of a gas meter in the gas leak alarm device shown by FIG. It is an example of the message | telegram structure used between the gas meter shown in FIG. 1, and a gas leak alarm. It is an example of the communication procedure used between the gas meter shown in FIG. 1, and a gas leak alarm.

Explanation of symbols

1 Gas meter 2 Gas leak alarm 11 μCOM (meter communication means)
17 Interface section (meter communication means)
21 μCOM (Alarm communication means)
24 Interface section (alarm communication means)

Claims (2)

In a gas meter provided with a meter communication means to which a gas leak alarm is connected and outputs a signal for detecting disconnection to the gas leak alarm,
The meter communication means determines whether or not a response signal from the gas leak alarm device has been input after outputting a signal for detecting the disconnection, and determines that the response signal has been input. When the subsequent communication with the gas leak alarm is performed by the method and it is determined that the response signal is not input, the subsequent communication with the gas leak alarm is performed by the pulse method or the ON / OFF method. Gas meter. In a gas leak alarm device comprising an alarm device communication means connected to a gas meter and detecting a signal detecting non-connection from the gas meter and outputting a response signal to the gas meter,
The alarm communication means determines whether or not a reply message for the response signal is input from the gas meter. When it is determined that the reply message is input from the gas meter, it communicates with the gas meter by a message method. And a gas leak alarm device that communicates with the gas meter by a pulse method or an ON / OFF method when it is determined that the reply message is not input from the gas meter.

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