JPH0660284A - Transmitting/receiving method for radio type alarm system - Google Patents

Abstract

PURPOSE:To shorten the operation period of time of a receiving circuit and to decrease the power consumption by encoding the alarm contents, adding an identification code, and transmitting the code subsequently to a reception waiting signal. CONSTITUTION:Both of a management device of a gas meter 17, etc., and an abnormality detector of a gas leakage alarm 10, etc., are provide with transmitting circuit 14, 21 and receiving circuit 15, 22, and to the receiving circuits 15, 22, a power source is supplied intermittently at a certain period. In such a state, when the abnormality detector detects abnormality, a reception waiting signal is transmitted first and the receiving circuit 22 of the management device side is set to a reception waiting state, and thereafter, an alarm signal consisting of an identification code and an alarm contents code is transmitted, and only for the minimum period of time until such time as this alarm signal is received by the receiving circuit 22 of the management device, the power source is supplied to the receiving circuit 22. In this case, when the alarm signal is received, the abnormality detector side is restored immediately to a regular intermittent receiving state by sending back a reception confirming signal which is not accompanied with the reception waiting signal to the abnormality detector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a transmission circuit and a reception circuit both in a management device such as a gas meter and an abnormality detector such as a gas leak alarm, and performs signal transmission between them by wireless signal line. The present invention relates to a method for transmitting and receiving signals in a wireless alarm system that does not require the work involved in laying.

[0002]

2. Description of the Related Art In this type of wireless alarm system,
In order to reduce power consumption, an intermittent reception method is adopted in which power is supplied intermittently to the receiving circuit at a fixed cycle, and a reception standby signal with a pulse width equal to or longer than the length of the reception cycle precedes the warning signal. It is publicly known that reliable reception can be performed by transmitting. However, this did not sufficiently reduce the power consumption.

Further, in Japanese Patent Laid-Open No. 3-154999, transmission and reception are synchronized between a management device and an abnormality detector, a reception standby signal shorter than the reception cycle is transmitted prior to an alarm signal, and the reception standby signal is transmitted. A method of continuing power supply to a receiving circuit for a predetermined time when receiving is disclosed. However, according to this, since the timer values of both the management device and the abnormality detector are deviated with time, it is necessary to resynchronize, so that it is suitable only for a system that transmits and receives several tens of times a day. It was

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to ensure that both the management device and the abnormality detector can minimize power consumption for transmission and reception in a wireless alarm system, and whether transmission and reception are performed reliably. It is to improve the reliability of signal transmission by making it possible to confirm whether or not it is possible.

[0005]

According to the present invention, both a management device such as a gas meter and an abnormality detector such as a gas leak alarm are provided with a transmission circuit and a reception circuit, and the reception circuit is intermittently provided at a constant cycle. In a wireless alarm system that supplies power,
When one side of the abnormality detector or the management device transmits a reception standby signal prior to the transmission of an alarm signal consisting of an identification code and an alarm content code, and the other side receives the reception standby signal, the reception circuit Power supply is extended until a warning signal is received, and when the warning signal is received, a reception confirmation signal without a reception standby signal is returned to one side.

[0006]

According to the present invention, for example, when an abnormality detector detects an abnormality, a reception standby signal is transmitted first to put the reception circuit on the management device side into a reception standby state, and then an identification code and an alarm content code are used. Only when the alarm signal is transmitted and the alarm signal is received by the receiving circuit of the management device, power is supplied to the receiving circuit. Then, when the alarm signal is received, by returning a reception confirmation signal without a reception standby signal to the abnormality detector, the abnormality detector side can be immediately returned to the normal intermittent reception state.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a wireless gas leak alarm system will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of a gas leak alarm device, which is an abnormality detector. The gas leak alarm 10 includes a transmitter / receiver 1
1 is connected. The transmitter / receiver 11 judges a change in the output of the gas leak alarm 10 and codes the microcomputer 12, and a transmission circuit 14 for modulating a signal from the microcomputer 12 and radiating the signal as a radio wave signal from an antenna 13. A receiving circuit 1 for demodulating a signal received by an antenna 13 and outputting it to the microcomputer 12.
5 and a power supply control circuit 16 which supplies a DC power supply voltage to the transmission circuit 14 and the reception circuit 15 in response to a control signal from the microcomputer 12.

FIG. 2 shows the configuration on the gas meter side, which is a management device. A transceiver 18 is also connected to the gas meter 17. The transmitter / receiver 18 does not have a microcomputer because the microcomputer 19 is built in the gas meter 17, but otherwise the same configuration as the transmitter / receiver 11 on the gas leak alarm 10 side, that is, the microcomputer built in the gas meter 17 is provided. Transmitting circuit 21 for modulating the signal from 19 and radiating it as a radio signal from antenna 20
A receiving circuit 22 that demodulates a signal received by the antenna 20 and outputs the demodulated signal to the microcomputer 19, and a transmitting circuit 21 according to a control signal from the microcomputer 19.
And a power supply control circuit 23 for supplying a DC power supply voltage to the receiving circuit 22.

When the gas leak alarm device 10 is a microcomputer built-in type, the gas leak alarm device 1
The transmitter / receiver 11 on the 0 side does not require the microcomputer 12.

In both the transceivers 11 and 18, the power supply voltage is not normally supplied to the transmission circuits 14 and 21, but the power supply voltage is supplied from the power supply control circuit 16.23 only during transmission. . Further, as shown in FIG. 3, the power supply voltage is supplied from the power supply control circuits 16 and 23 to the receiving circuits 15 and 22 intermittently by the time width t ₁ having a constant period T ₁ (for example, 5 ms at intervals of 5 seconds). It is supposed to be done.

Next, the operation will be described with reference to the timing chart of FIG. The gas leak alarm 10 detects a gas leak, and (1) of FIG.
When the microcomputer 12 detects that a change has occurred in the output signal shown in FIG.
Outputs to the power supply control circuit 16 a signal for stopping the supply of the power supply voltage to the receiving circuit 15 and for supplying the power supply voltage to the transmitting circuit 14. As a result, the power supply voltage is supplied to the transmission circuit 14 as shown in (2) of FIG.

After that, the microcomputer 12 sends to the transmission circuit 14 a reception standby signal having a pulse width (for example, HIGH for only 5 seconds) which is equal to or longer than the length T ₁ of the reception cycle as shown in (3) of FIG. Then, the alarm signal is sent after a short time. As shown in FIG. 5, the alarm signal is composed of an identification code stored in the ROM of the microcomputer 12 and a code indicating the alarm content according to the change of the output signal from the gas leak alarm device 10. Are sent continuously. When the transmission is completed, the supply of the power supply voltage to the transmission circuit 14 is stopped, while (4) in FIG.
The power supply voltage is supplied to the receiving circuit 15 as shown in FIG. The reception standby signal and the alarm signal sent to the transmission circuit 14 are
For example, it is FM-modulated and radiated from the antenna 13 as a radio signal.

The same identification code is stored in the microcomputer 12 on the side of the gas leak alarm 10 and the microcomputer 19 on the side of the gas meter 17, and since the codes are different for each house, they are paired with themselves. It is determined whether or not it is an alarm signal from a device that is installed, and it does not respond to the alarm signals of other adjacent houses.

When the receiving circuit 15 is in the reception standby state when the output signal from the gas leak alarm 10 changes, until the reception of the signal ends or until a certain time elapses from the time when the output signal changes. Transmission from the transmission circuit 14 is not performed.

On the other hand, in the transmitter / receiver 18 on the gas meter 17 side, if there is a signal input from the antenna 20 within a short time t ₁ when the receiving circuit 22 is intermittently supplied with the power supply voltage and is in a receivable state, demodulation is performed. The signal is sent to the microcomputer 19 in the gas meter 17. When the demodulated signal is determined to be the reception standby signal, the microcomputer 19 sends a signal to the power supply control circuit 23 to supply the power supply voltage to the reception circuit 22 as shown in (5) of FIG. Extend until reception is completed.

When the reception circuit 22 receives the alarm signal following the reception standby signal as shown in FIG. 4 (6), the identification code sent from the microcomputer 19 coincides with its own identification code. If there is a match, the alarm content code sent subsequently is analyzed.
Then, when the microcomputer 19 determines that the alarm content code is other than the predetermined regular code, the microcomputer 19 ignores the alarm signal, and the power supply control circuit 23
The receiving circuit 22 is returned to the original intermittent receiving state via. If the code is legitimate, supply of the power supply voltage to the transmission circuit 21 is started as shown in (7) of FIG. 4, and the identification shown in FIG. 6 is shown as a reception confirmation signal as shown in (8) of FIG. After transmitting the code, the power supply voltage supply to the transmission circuit 21 is stopped, and the original intermittent power supply state is restored.

After that, when the gas leak alarm device 10 no longer detects the gas leak and the alarm signal indicating the normal recovery is not sent for a certain period of time, the microcomputer 19 is built in the gas meter 17. Perform processing such as closing the shutoff valve.

If the identification codes do not match when the alarm signal is received, the following content code is ignored and the power supply voltage supply to the receiving circuit 22 is returned to the intermittent state. Further, even if the identification code is not sent within a fixed time after the reception standby state, the intermittent reception state is restored.

The transmitted reception confirmation signal is received by the receiving circuit 15 via the antenna 13 in the transmitter / receiver 11 on the gas leak alarm 10 side and is sent to the microcomputer 12 as a demodulation signal. The microcomputer 1
If the received identification code coincides with its own unique identification code, it judges that the alarm signal transmitted by itself is normally received by the gas meter 17 side, and the receiving circuit 1
The power supply voltage supply to 5 is returned to the intermittent state.

If the identification code as the reception confirmation signal is not returned within the set time, the microcomputer 12 determines that the alarm signal was not correctly transmitted due to noise or the like, and supplies the power supply voltage to the reception circuit 15. While stopping, the power supply voltage is supplied to the transmitting circuit 14, and again, similarly, the reception standby signal is followed by an alarm signal including an identification code and an alarm content code. Here, if the reception confirmation identification code is not returned again, the same transmission is repeated up to the set number of repeated transmissions.

FIG. 8 shows the flow of the above operation. The operation is summarized as follows. Gas leak alarm 1
On the 0 side, the output of the gas leak alarm 10 changes and the transmission circuit 1
When the power supply voltage is supplied to No. 4 and the reception standby signal and the alarm signal are sent, the supply of the power supply voltage to the transmission circuit 14 is stopped, while the power supply voltage is supplied to the reception circuit 15 to make it in the receivable state.

On the gas meter 17 side, if the HIGH state due to the reception standby signal continues within the receivable time for each fixed period, the power supply voltage is continuously supplied to the receiving circuit 22 and the subsequent alarm signal is received. When this is received, the power supply voltage supply to the receiving circuit 22 is stopped, and when the alarm signal is correctly received, the power supply voltage is supplied to the transmitting circuit 21 to transmit the reception confirmation signal, and then the receiving circuit 22 is sent to the transmitting circuit 21. The supply of the power supply voltage is stopped and the receiving circuit 22 is returned to the intermittent receiving state. When the reception confirmation signal is correctly received on the gas leak alarm device 10 side, the reception circuit 15 is returned to the intermittent reception state.

As described above, when the output of the gas leak alarm device 10 changes, by transmitting the code according to the content, the transmission / reception time can be shortened and the power consumption can be reduced. Further, by returning the reception confirmation signal, the reliability of signal transmission can be improved. At that time, the gas leak alarm device 10 side puts it in a reception standby state after transmission, and the gas meter 17 side sends back only a reception confirmation signal without a reception standby signal, so that the transmission / reception time can be shortened, and the battery power of the gas meter 17 side ( For example, it is possible to suppress the consumption of the lithium battery) and reliably transmit and receive the alarm signal.

The alarm signal may be composed only of the identification code and the alarm content code as shown in FIG. 5, but as shown in FIG. 7, a bit inversion code or a checksum may be added, or the same content may be added. The reliability can be further improved by duplicating. Similarly, the reception confirmation signal is also shown in FIG.
Reliability is improved by adding a checksum or the like to the identification code.

The case where a signal is sent from the gas leak alarm device 10 side to the gas meter 17 side has been described above as an example. Conversely, when a signal is sent from the gas meter 17 side to the gas leak alarm device 10 side, transmission / reception can be performed in the same manner. . Also, the transmitter / receiver 11.1
Although the example in which 8 is connected to the outside of each of the gas leak alarm 10 and the gas meter 17 is shown, it may be built-in type. Furthermore, the present invention can be similarly applied to wireless transmission by infrared rays or the like, or to other wireless security systems other than the gas leak alarm system.

[0027]

The present invention has the following effects. Rather than transmitting and receiving the same signal as wired, the alarm content is coded and an identification code is added, and these codes are transmitted following the reception standby signal, so the operating time of the transceiver circuit can be shortened and power consumption can be reduced. .

When the reception standby signal is transmitted prior to the transmission of the alarm signal and the reception side receives the reception standby signal,
Reliable wireless alarm system that extends power supply to the receiving circuit until an alarm signal is received and sends a reception confirmation signal back to the sender when the alarm signal is normally received, so that reliable signal transmission is possible Can be

When the reception confirmation signal is sent back to the transmission side, since it is sent back without the reception standby signal, the time required for the reply is short, and even if the reception confirmation signal is sent back, the power consumption is increased. It can be kept low.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration on a gas leak alarm side of a wireless gas leak alarm system to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration on a gas meter side.

FIG. 3 is a timing chart showing that the power supply voltage is intermittently supplied to the receiving circuits on the gas leak alarm side and the gas meter side.

FIG. 4 is a timing chart showing the operation on the gas leak alarm side and the gas meter side.

FIG. 5 is a diagram showing a format of an alarm signal transmitted from the gas leak alarm device side to the gas meter side.

FIG. 6 is a diagram showing a format of a reception confirmation signal returned from the gas meter side to the gas leak alarm side.

FIG. 7 is a diagram showing another example of a format of an alarm signal.

FIG. 8 is a flowchart showing a flow of operations on the gas leak alarm side.

[Explanation of symbols]

 10 Gas Leak Alarm 11 Transmitter / Receiver 12 Microcomputer 13 Antenna 14 Transmission Circuit 15 Reception Circuit 16 Power Supply Control Circuit 17 Gas Meter 18 Transceiver 19 Microcomputer 20 Antenna 21 Transmission Circuit 22 Reception Circuit 23 Power Supply Control Circuit

Claims (1)

[Claims] 1. A wireless alarm system comprising a transmission circuit and a reception circuit both in a management device such as a gas meter and an abnormality detector such as a gas leak alarm, and which intermittently supplies power to the reception circuit at a constant cycle. In the above, from one side of the abnormality detector or the management device, a reception standby signal is transmitted prior to the transmission of an alarm signal composed of an identification code and an alarm content code, and when the other side receives the reception standby signal, A wireless system, characterized in that the power supply to the receiving circuit is extended until the alarm signal is received, and when the alarm signal is received, a reception confirmation signal without a reception standby signal is returned to one side. Alarm system transmission and reception method.