JP3702006B2 - Gas monitoring system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a gas monitoring system using a subscriber telephone line.
[0002]
[Prior art]
This type of gas monitoring system uses an automatic telephone for gas consumption, reading of pressure gauges for detecting gas leaks and generation of raw gas, opening and closing of gas main plugs, etc. It is performed in a time zone that does not collide with the customer's telephone usage such as early morning. FIG. 1 shows a system diagram common to the conventional example and the present invention. First, an NRT device 22 installed in a receiving side switch 21 is selected from a gas monitoring center 1 by a specific telephone number, and then demand is increased. When the home subscriber telephone number is selected, a call signal having a frequency (2080 Hz or push button signal frequency) different from the normal (400 Hz: 16 Hz modulation) is sent from the exchange 21 to the customer, and the customer's telephone 4 is ringed. Without receiving to the terminal NCU5. FIG. 5 shows an internal circuit diagram of the terminal NCU 5 used in the above system. The no ringing detection circuit 8 determines whether the call is a normal call or a call using an NRT (no ringing line) by using a ringing signal. In this case, the input gate of the signal processing circuit 9 is turned on, data is transmitted and received between the microcomputer type gas meter (commonly known as the microcomputer meter) 2 and the monitoring center 1, and automatic meter reading of gas usage is performed. Note that the contact point 12a of the telephone disconnecting relay 12 is kept closed, and even when NRT communication is in progress, when a call is made from the customer, the NRT communication is immediately interrupted, so Prioritize usage. Further, when communication is performed by calling the center 1 side from the microcomputer meter 2, the telephone blocking relay 12a is closed to use a normal call. In the figure, reference numeral 13 denotes a noise filter.
[0003]
[Problems to be solved by the invention]
In ordinary households, opening and closing of the gas main plug or opening after the operation of the seismic device when going out for a long time is usually performed manually by the customer himself, but for the customer unfamiliar with the operation of the equipment, the above-mentioned A gas monitoring system is used to open and close the main plug by remote control using a telephone line from the gas monitoring center in response to a telephone request. This service, however, checks the requester's phone number, hangs up the phone, and then uses the NRT line for remote control. This takes a lot of work, especially after an earthquake. There was a problem that there was a lack of personnel in addition to congestion. The present invention has been made in view of such a problem, and an object of the present invention is to provide a system of this kind that allows a customer to open and close the main plug from the telephone.
[0004]
[Means for Solving the Problems]
As shown in FIGS. 1 and 2, the gas monitoring system according to the present invention transmits / receives data between the monitoring center 1 and the microcomputer meter 2 of a general consumer by using a subscriber telephone line 3 of each consumer. In a gas monitoring system using a so-called no-ringing (NRT) communication that does not ring a home telephone, it has a function of discriminating a call signal from the office line 3 and automatically switching between the microcomputer meter 2 and the consumer telephone 4 The terminal NCU (network control unit) 5 determines a plurality of digits from the top of the selection signal transmitted from the customer's telephone 4 and disconnects the connection to the office line 3 when the specific number is determined. The control circuit 6 is provided with a control circuit 6 for sending a control signal similar to NRT communication to the terminal NCU5 to open and close the gas main plug.
[0005]
[Action]
In the above-described configuration, when the control circuit 6 determines the upper multiple digits of the selection signal (telephone number) transmitted from the customer's telephone 4 and it matches the preset specific number, The relay contact 7a for disconnecting the office line is disconnected to interrupt the call to the exchange 21, and a pseudo call signal similar to the call signal used for no-ringing communication and a necessary control signal are sent to the terminal NCU 5, The no-ringing detection circuit 8 opens the input gate 10a of the signal processing circuit 9, or, as shown in the embodiment of FIG. 4, sends a signal to the terminal 11 that is separately assigned for controlling the main plug to open / close the gas main plug Let the operation be performed. When the selection signal from the customer's telephone 4 does not match the specific number, the control circuit 6 does not operate and a normal call is made through the exchange 21. Furthermore, even when there is an incoming signal from the office line 3 side, regardless of whether the calling signal has a ringing frequency (400 Hz: 16 Hz modulation) or no ringing frequency (usually 2080 Hz or a push button signal frequency is used). The control circuit 6 does not operate.
[0006]
【Example】
1 to 4 show an embodiment of a gas monitoring system according to the present invention. Data transmission / reception between the monitoring center 1 and a general customer's microcomputer meter 2 is performed using a subscriber telephone line 3 of each consumer. First, the NRT device 22 provided in the receiving side switch 21 is called from the center 1 through the general telephone line, and the telephone number of the customer is waited for the second dial request signal returned from the NRT device 22. Is dialed, a no-ringing call signal (for example, push button signal “5”) is sent from the exchange 21 to the customer, and the customer's telephone 4 is not ringed and arrives at the terminal NCU5. In the terminal NCU 5, the no-ringing detection circuit 8 detects the no-ringing call signal, and immediately opens the input gate 10 a of the signal processing circuit 9 to enable data communication between the microcomputer meter 2 and the monitoring center 1 via the modem 10. The contents of data communication include, for example, automatic meter reading by command from the center, that is, reading of gas flow accumulator, gas leak detection by reading the pressure gauge during a certain period of blockage operation of gas main plug, pressure measurement and continuous gas usage time measurement Detection of abnormalities due to the above, collection of temporal or seasonal distribution data of gas usage, changes of various set values, and the like.
[0007]
As shown in FIG. 3, the control circuit 6 is connected between the no-ringing detection circuit 8 of the terminal NCU 5 and the office line connection terminal, and the consumer directly controls the micrometer 2 from the telephone 4 at home. This is for opening and closing the gas main valve. A selection signal discrimination unit 15 for discriminating a plurality of digits from the top of the selection signal transmitted from the telephone 4 of the consumer, and a specific number is discriminated by the selection signal discrimination unit 15 When receiving a signal, a relay driving unit 7 for cutting off the connection to the office line 3, a no-ringing signal sending unit for sending a no-ringing call signal to the terminal NCU 5 after cutting off the office line, and a response signal for the no-ringing call are received. And a signal processing unit 16 including a modem for transmitting control data. This control circuit 6 does not operate in response to an external ringing or no ringing call signal, but a call signal (signal from which the handset is removed) and a selection signal (dial signal) from the customer's telephone 4 or a microcomputer meter When calling the monitoring center 1 from the second side, a selection signal sent from the terminal CPU 5 is detected, and when the upper three digits of the telephone number constituting the selection signal are a specific number, for example, “000”, the relay 17 When the number dialed from the telephone 4 is “1”, for example, the gas main valve is “closed”, and when the number dialed from the telephone 4 is “2”, the gas main valve is “open”. It recognizes and transmits a predetermined control signal to the microcomputer meter 2 side.
[0008]
In the above embodiment (FIG. 3), the control signal sent from the control circuit 6 to open and close the gas main valve has the same frequency as the no ringing call signal (for example, 770 Hz and 1336 Hz representing the push button signal “5”). A pseudo call signal and a digital data signal transmitted / received through a modem. First, the input gate 10a of the signal processing circuit 9 is opened by the pseudo call signal, and then the main plug control function is operated to the microcomputer meter 2 by data communication. ing. FIG. 4 shows another embodiment of the present invention. A no-ringing pseudo call signal (PB signal “5”) for calling a data communication function as a control signal sent from the control circuit 6 to the microcomputer meter 2 side. ) And a pseudo-paging signal having a frequency different from (for example, 697 Hz and 1209 Hz representing the push button signal “1” are used as the main plug “open”, and 697 Hz and 1336 Hz representing “2” are used as the main plug “closed”). The no-ringing detection circuit 8 discriminates three types of calling signals, and in the case of a main plug control signal, sends a signal to the main plug opening / closing terminal 11 so as to specify the main plug opening / closing function without passing through the modem 10. In this way, the system configuration can be simplified, such as eliminating the need for a modem unit in the control circuit 6.
[0009]
【The invention's effect】
According to the present invention, as described above, in a gas monitoring system that performs automatic meter reading and abnormality detection of a general household gas meter using a public line, switching between the telephone 4 of the consumer and the microcomputer type gas meter 2 is performed. By simply adding a simple control circuit 6 to the terminal NCU 5 that is currently being used, the customer's telephone 4 can be dialed only by opening and closing the gas main plug when the customer goes out for a long time or opening the seismic device. Therefore, even a consumer who does not know the installation location of the gas main tap or cannot distinguish between the gas tap and the water tap has the advantage that the gas main tap can be opened and closed very easily. In addition, since the gas monitoring center 1 used to provide a main switch opening / closing service via a telephone line in response to a telephone request from a customer after the seismic device was activated, the telephone number of the client was confirmed one by one, and a call was made once. It is necessary to remotely control the microcomputer meter using the NRT line after disconnecting, and it takes a lot of time and there is a problem that the telephone line is congested especially immediately after the occurrence of an earthquake. Therefore, there are advantages that these problems can be solved and telephone usage fees can be reduced.
[Brief description of the drawings]
FIG. 1 is a general system diagram common to the present invention and a conventional example.
FIG. 2 is a block diagram of an embodiment of the system of the present invention.
FIG. 3 is a block diagram of a terminal NCU used in the above.
FIG. 4 is a block diagram of the main part of the above.
FIG. 5 is a block diagram of a conventional terminal NCU.
[Explanation of symbols]
1 Gas Monitoring Center 2 Microcomputer Gas Meter 3 Subscriber Telephone Line or Office Line 4 Telephone 5 Terminal NCU (Network Control Unit)
6 Control circuit 7 Relay for disconnecting the local line 8 No-ringing detection circuit 9 Signal processing circuit 10 Modem 11 Terminal plug terminal 12 Telephone relay 13 Noise filter 14 Tone dialer 15 Selection signal determination unit 16 Signal processing unit

Claims (1)

In a gas monitoring system in which control communication between a gas monitoring center and a microcomputer gas meter of a general consumer is performed by a no ringing (NRT) communication that does not ring a consumer's telephone using a subscriber telephone line of each consumer The terminal NCU having a function of automatically switching between the gas meter and the customer's telephone by discriminating the calling signal from the office line is discriminated from the most significant digit of the selection signal transmitted from the customer's telephone. And a means for disconnecting the connection to the local line and sending a control signal for opening and closing the gas main plug similar to NRT communication to the terminal NCU when the specific number is determined by the determining means A gas monitoring system with an attached circuit.

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