JPH07210791A - Transmission equipment - Google Patents

Abstract

PURPOSE:To provide an automatic meter inspection system which can increase the timing matching time interval of intermittent receiving operation and prolong the life of a battery. CONSTITUTION:A master device consists of a T-NCU 10 connected to a telephone line and a transmission equipment, and a slave device consists of a flowmeter 12 and a transmission equipment; and the transmission equipment is equipped with a receiving means 18 which receives a radio wave, a clock generating means 19, a timer means 20 which measures a time on the basis of the clock signal from the clock generating means 19, an intermittency control means 21 which controls the operation of the intermittent receiving means 18 at time intervals under the control of the timer means 20, a reference signal generating means 26 which operates intermittently, and a time error detecting means 27 which detects the time error between the signal from the reference signal generating means 26 and the signal from the clock generating means 19, and is so constituted as to correct the time measurement of the timer means 20 with the time error detection signal from the time error detecting means 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic meter reading system for measuring an integrated value of the amount of gas, water, electricity, etc. used by a gas meter, a water meter, an electric power meter, etc. The present invention relates to a transmission device used.

[0002]

2. Description of the Related Art In recent years, a so-called automatic meter reading system has been introduced which absorbs an integrated value measured by a meter from a remote place using a telephone line or the like. In addition, it has been attempted to connect the telephone line and the meter by a wireless line. FIG. 3 shows a block diagram of a conventional wireless automatic meter reading system and a transmission device used therein, which will be described. 3A shows the configuration of the parent device, and FIG. 3B shows the configuration of the child device.

In FIG. 3A, 1 is an antenna, 2 is transmitting means, 3 is channel selecting means, 4 is signal generating means, 5 is receiving means, 6 is clock generating means, 7 is timer means, and 8 is intermittent. It is a control means and constitutes the transmission device 12. Reference numeral 9 is a public telephone line, 10 is a no-ringing network control unit (hereinafter referred to as T-NCU) connected to the public telephone line 9, 11 is an interface unit, and T-NC.
Data collection means 1 by U10 and interface means 11
Make up three.

In FIG. 1B, 14 is an antenna and 1
5 is transmitting means, 16 is channel selecting means, 17 is signal generating means, 18 is receiving means, 19 is clock generating means,
Reference numeral 20 is a timer means, and 21 is an intermittent control means, which constitutes a transmission device 25. Reference numeral 22 is a gas pipe connected to the home, 23 is a gas flow meter (so-called gas meter) provided in the middle of the gas pipe 22 for measuring the amount of gas used in the target home, and 24 is a storage means.

The parent device and the child device are driven by a battery, and an intermittent reception system is adopted to extend the battery life.
In the intermittent control means 8 and 21, for example, 20 m at intervals of 30 seconds
Power is supplied to the receiving means 5 and the receiving means 18 only for a second to enter the receiving state. If it is necessary to transmit data to the other party, the radio wave is transmitted at the timing of the above-mentioned 30 second interval which is synchronized with the other party. As a radio wave to be used, a radio wave in the 400 MHz band, which has recently been approved for use as a low power radio, is used. The channel selecting means 3 and the channel selecting means 16 are for selecting the frequency of the radio wave to be transmitted and received. The channel selecting means 3 and the channel selecting means 16 have a so-called PLL (PHASE LOCKED LOOP) system configuration. Signal generating means 4 and signal generating means 17
Is a crystal oscillator and serves as a reference frequency for determining the channel frequency of the channel selecting means 3 and the channel selecting means 16. ± 4ppm by law for small power radio
It is stipulated that the following frequency accuracy is required. In order for the parent device and the child device to perform the transmission operation and the reception operation at the same time in synchronization with each other, the clock generation means 6 for determining the operation time of the intermittent control means 8 and the intermittent control means 21.
And the clock frequency of the clock generation means 19 must match without any deviation. The timer means 7 and the timer means 20 measure the intermittent operation time intervals by counting the clock pulses from the clock generating means 6 and the clock generating means 19. Generally, clock generation means 6
A crystal oscillator is used as the clock generation means 19, but the clock frequencies of the clock generation means 6 and the clock generation means 19 do not match due to the influence of temperature and the initial adjustment error. As a result, the intermittent operation timings of the two shift with time. Therefore, a signal for timing adjustment is transmitted from the parent device before the intermittent operation timing is significantly deviated. For example, if the frequency accuracy of the crystal oscillators used for the clock generating means 6 and the clock generating means 19 is ± 50 ppm, the worst case will be a deviation of ± 100 ppm between the parent device and the child device. Therefore, for example, in 10 minutes, there is a deviation of ± 60 msec. Therefore, the parent device transmits the timing adjustment signal at 10-minute intervals by slightly lengthening the preamble signal transmitted at the time of transmission so that the child device can receive the signal even if it is deviated by ± 60 msec. When the slave device receives the signal for timing adjustment from the master device, it controls the timer means 20 and corrects the start time of the timer means 20. The above operation cancels the intermittent operation timing deviation every 10 minutes, so that the intermittent operation timing deviation is not accumulated over 10 minutes or more.

[0006]

However, in the configuration of the above-mentioned conventional transmission device, the time interval at which the master device transmits the timing adjustment signal is determined by the maximum difference between the clock frequencies of the master device and the slave device. Therefore, when a normal crystal oscillator is used, it is necessary to transmit and receive the timing adjustment signal at a time interval of about 10 minutes, which causes a deterioration in battery life. Further, when a crystal oscillator with high frequency accuracy is used, the time interval can be lengthened, but there is a problem that such a high-precision crystal oscillator is very expensive.

The transmission apparatus of the present invention is intended to solve the above-mentioned problems, and an object thereof is to realize a transmission apparatus capable of extending the transmission / reception cycle of a timing adjustment signal and thereby extending the battery life.

In the configuration of the conventional automatic meter reading system using the above-mentioned conventional transmission device, the warranty period of the meter is 1
For zero years it has not been possible to operate an automatic meter reading system without battery replacement.

The automatic meter-reading system of the present invention solves the above-mentioned problems, and an object thereof is to realize an automatic meter-reading system which continues to operate for 10 years without battery replacement.

[0010]

In order to achieve the above object, the transmission device of the present invention comprises a receiving means for receiving radio waves,
Clock generating means, timer means for measuring time based on the clock signal from the clock generating means, intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, and intermittently. The reference signal generating means, the time error detecting means for detecting a time error between the signal from the reference signal generating means and the signal from the clock generating means, and the time error detecting signal from the time error detecting means. It is configured to correct the time measurement of the timer means.

Further, in the automatic meter-reading system of the present invention, the parent device is a data collection means for collecting measurement data of the flow meter,
A data collection request signal from the data collection means or a transmission means for transmitting a response signal to the measurement data from the flowmeter on a carrier wave, and a reception means for receiving the measurement data from the flowmeter, The slave device includes a flow meter, a storage unit that electronically stores measurement data from the flow meter, a transmission unit that transmits the measurement data from the storage unit on a carrier wave signal, and measurement data from the storage unit. Of the request signal for requesting the transmission of the data or the response signal to the measurement data, the clock generating means, the timer means for measuring the time based on the clock signal from the clock generating means, and the control of the timer means. Intermittent control means for intermittently controlling the operation of the receiving means at time intervals; reference signal generating means for intermittent operation; A time error detecting means for detecting a time error between the signal from the signal generating means and the signal from the clock generating means is provided, and the time measurement of the timer means is corrected by the time error detecting signal from the time error detecting means. Is configured.

Further, in the automatic meter-reading system of the present invention, the parent device is a data collecting means for collecting the measurement data of the flow meter,
A transmitting means for transmitting a data collection request signal from the data collecting means or a response signal to the measurement data from the flowmeter on a carrier wave; a receiving means for receiving the measurement data from the flowmeter; and a clock generating means. A timer means for measuring time based on a clock signal from the clock generating means, an intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, and a reference for intermittently operating The timer means includes a signal generating means, a time error detecting means for detecting a time error between the signal from the reference signal generating means and the signal from the clock generating means, and the timer means by the time error detecting signal from the time error detecting means. Is configured to correct the time measurement of the flowmeter, while the slave device electronically stores the flowmeter and the measurement data of the flowmeter. Storage means, transmission means for transmitting the measurement data from the storage means on a carrier wave signal, and reception means for receiving a request signal requesting transmission of the measurement data from the storage means or a response signal to the measurement data. It is composed of.

Further, in the automatic meter-reading system of the present invention, the parent device is a data collection means for collecting measurement data of the flow meter,
A transmitting means for transmitting a data collection request signal from the data collecting means or a response signal to the measurement data from the flowmeter on a carrier wave; a receiving means for receiving the measurement data from the flowmeter; and a clock generating means. A timer means for measuring time based on a clock signal from the clock generating means, an intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, and a reference for intermittently operating A signal generating means and a time error detecting means for detecting a time error between the signal from the reference signal generating means and the signal from the clock generating means, while the slave device is a flow meter and a measurement by the flow meter. Storage means for electronically storing data, and transmission means for transmitting the measurement data from the storage means on a carrier wave signal,
Receiving means for receiving a request signal requesting transmission of measurement data from the storage means or a response signal to the measurement data, clock generating means, and timer means for measuring time based on the clock signal from the clock generating means. An intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, a reference signal generating means for intermittently operating, a signal from the reference signal generating means and the clock generating means A time error detection means for detecting a time error of the signal from the parent device and the child device, and the time error detection signal from the time error detection means is configured to correct the time measurement of the timer means. is there.

The reference signal generating means used in the above-mentioned structure receives the signal from the receiving means for receiving the electric wave from the transmitting apparatus which transmits the electric wave intermittently at a predetermined time interval, and the transmitting apparatus. The output signal is the time interval of the radio wave from.

Further, the reference signal generating means used in the above configuration is also used as the signal generating means for determining the frequency to be received by the receiving means.

[0016]

With the above arrangement, the transmission device of the present invention can detect the clock frequency shift between the parent device and the child device and change the count value of the timer means in the direction of eliminating the clock frequency shift between them. Therefore, the transmission / reception interval of the timing adjustment signal can be lengthened.

Further, the automatic meter reading system of the present invention can construct an automatic meter reading system that continues to operate with a battery for 10 years by the above configuration.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1A shows the configuration of the parent device, and FIG. 1B shows the configuration of the child device. The same functional blocks as in the conventional example are given the same numbers. In FIG. 1A, 1 is an antenna, 2 is transmitting means, 3 is channel selecting means, 4 is signal generating means, 5 is receiving means, 6 is clock generating means, 7 is timer means, and 8 is intermittent control means. The transmission device 29 is configured. Reference numeral 9 is a public telephone line, 10 is a no-ringing network control means (hereinafter referred to as TN) connected to the public telephone line 9.
CU), 11 is an interface means, and
-The NCU 10 and the interface means 11 constitute the data collecting means 13.

In FIG. 1 (B), 14 is an antenna, 1
5 is transmitting means, 16 is channel selecting means, 17 is signal generating means, 18 is receiving means, 19 is clock generating means,
Reference numeral 20 is a timer means, and 21 is an intermittent control means, which constitute a transmission device 30. Reference numeral 22 is a gas pipe connected to the home, 23 is a gas flow meter (so-called gas meter) provided in the middle of the gas pipe 22 for measuring the amount of gas used in the target home, and 24 is a storage means. Reference numeral 26 is a reference signal generating means, and 27 is a time error detecting means.

The parent device and the child device are driven by a battery, and an intermittent reception system is adopted to extend the battery life.
That is, as in the conventional example, the timing adjustment signal is transmitted from the parent device (A) at intervals of 10 minutes. In the slave device (B), when the timing adjusting signal from the parent device (A) is received by the receiving means 18, the reference signal generating means 26 synchronizes with the timing adjusting signal based on the timing adjusting signal received by the receiving means 18. The signal is output every 10 minutes. The time error detecting means 27 measures the timing matching signal interval from the reference signal generating means 26 with the signal from the clock generating means 19. For example, it is assumed that the timing matching signal interval measured by the signal from the clock generating means 19 is 10 minutes and 10 milliseconds. Then, the time error detection means 27 outputs an error signal of 10 msec assuming that the timing adjustment signal interval is a correct 10 minute interval. This error signal controls the timer means 20 to cause the timer means 20 to generate an output every 10 minutes and 10 milliseconds in the time measurement by the signal from the clock generating means 19. Therefore, the output of the timer means 20 has the same time interval as the timing adjustment signal. Therefore, even if the time interval of the timing adjustment signal is made longer than 10 minutes, for example, about every hour, the timing of the intermittent operation of the parent device (A) and the child device (B) does not largely deviate. That is, since the transmission interval of the timing adjustment signal can be lengthened, the transmission power of the timing adjustment signal can be reduced for the parent device (A), and the child device (B) can be reduced.
Therefore, the reception power of the timing adjustment signal can be reduced. Therefore, the battery life is extended for both the parent device (A) and the child device (B).

Another embodiment of the present invention will be described with reference to FIG. 2A shows the configuration of the parent device, and FIG. 2B shows the configuration of the child device. The same functional blocks as those in the embodiment of FIG. 1 are assigned the same numbers. In FIG. 2A, 1
Is an antenna, 2 is a transmitting means, 3 is a channel selecting means,
Reference numeral 4 is a signal generating means, 5 is a receiving means, 6 is a clock generating means, 7 is a timer means, and 8 is an intermittent control means, which constitutes a transmission device 29. Reference numeral 9 is a public telephone line, 10 is a no-ringing network control unit (hereinafter referred to as T-NCU) connected to the public telephone line 9, 11 is an interface unit, and the T-NCU 10 and the interface unit 11 constitute a data collecting unit 13. is doing.

In FIG. 2B, 14 is an antenna and 1
5 is transmitting means, 16 is channel selecting means, 17 is signal generating means, 18 is receiving means, 19 is clock generating means,
Reference numeral 20 is a timer means, and 21 is an intermittent control means, which constitute a transmission device 30. Reference numeral 22 is a gas pipe connected to the home, 23 is a gas flow meter (so-called gas meter) provided in the middle of the gas pipe 22 for measuring the amount of gas used in the target home, and 24 is a storage means. 27 is a time error detection means.

The parent device and the child device are driven by a battery, and an intermittent reception system is adopted to extend the battery life.
The signal generation means 4 and the signal generation means 17 are intermittent control means 8
And the intermittent control means 21 operates intermittently. Then, the signal generating means 4 and the signal generating means 17 have frequency accuracy of ± 4.
Generates highly accurate signals below ppm. The signal frequency from the signal generating means 4 and the signal generating means 17 is compared with the signal frequency from the clock generating means 6 and the clock generating means 19 in the time error detecting means 28 and the time error detecting means 27, and the time error signal is time error. Output from the detection means 28 and the time error detection means 27. The timer means 7 and the timer means 20 are controlled by this time error signal so that the time interval measured with the frequency accuracy of the signal generating means 4 and the signal generating means 17 is reached. Therefore, the accuracy of the intermittent operation is ± 4ppm in absolute error for both the parent device (A) and the child device (B).
It becomes the following. Therefore, the time interval of the intermittent operation can be made longer than 10 minutes, for example, every hour, and the battery life can be extended.

A clock of a microcomputer may be used as the reference signal generating means.

[0025]

As described above, according to the transmission apparatus of the present invention, the receiving means for receiving the radio wave, the clock generating means, and the timer means for measuring the time based on the clock signal from the clock generating means, From the intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, the reference signal generating means operating intermittently, the signal from the reference signal generating means and the clock generating means. The time error detection means for detecting the time error of the signal of (1) and the time error detection signal from the time error detection means are configured to correct the time measurement of the timer means, so that the intermittent time interval is lengthened. This has the effect of extending the battery life.
Further, by sharing the signal generating means serving as the reference frequency of the PLL and the reference signal generating means, the absolute accuracy can be improved without increasing the number of parts.

Further, according to the automatic meter reading system of the present invention using the above-mentioned transmission device, the consumption of the battery can be extremely reduced, so that there is an effect that the battery can be operated for 10 years without battery replacement.

[Brief description of drawings]

FIG. 1 is a block diagram of a transmission device and an automatic meter reading system using the same according to an embodiment of the present invention.

FIG. 2 is a block diagram of a transmission device and an automatic meter reading system using the same according to another embodiment of the present invention.

FIG. 3 is a block diagram of a conventional transmission device and an automatic meter reading system using the same.

[Explanation of symbols]

 2 transmitting means 3 channel selecting means 4 signal generating means 5 receiving means 6 clock generating means 7 timer means 8 intermittent control means 10 T-NCU 15 transmitting means 16 channel selecting means 17 signal generating means 18 receiving means 19 clock generating means 20 timer means 21 intermittent control means 23 flow meter 24 storage means 26 reference signal generation means 27 time error detection means

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[Procedure amendment]

[Submission date] April 21, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Transmission device

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is a gas meter and water meters, gas by the power meter or the like, measuring water, the integrated value of the amount of electricity, etc., order to suck up the integrated value from the remote
The present invention relates to a transmission device.

[0002]

2. Description of the Related Art In recent years, a so-called automatic meter reading system has been introduced which absorbs an integrated value measured by a meter from a remote place using a telephone line or the like. In addition, it has been attempted to connect the telephone line and the meter by a wireless line. FIG. 3 shows a block diagram of a conventional wireless automatic meter reading system and a transmission device used therein, which will be described. 3A shows the configuration of the parent device, and FIG. 3B shows the configuration of the child device.

In FIG. 3A, 1 is an antenna, 2 is transmitting means, 3 is channel selecting means, 4 is signal generating means, 5 is receiving means, 6 is clock generating means, 7 is timer means, and 8 is intermittent. It is a control means and constitutes the transmission device 12. Reference numeral 9 is a public telephone line, 10 is a no-ringing network control unit (hereinafter referred to as T-NCU) connected to the public telephone line 9, 11 is an interface unit, and T-NC.
Data collection means 1 by U10 and interface means 11
Make up three.

In FIG. 1B, 14 is an antenna and 1
5 is transmitting means, 16 is channel selecting means, 17 is signal generating means, 18 is receiving means, 19 is clock generating means,
Reference numeral 20 is a timer means, and 21 is an intermittent control means, which constitutes a transmission device 25. Reference numeral 22 is a gas pipe connected to the home, 23 is a gas flow meter (so-called gas meter) provided in the middle of the gas pipe 22 for measuring the amount of gas used in the target home, and 24 is a storage means.

The parent device and the child device are driven by a battery, and an intermittent reception system is adopted to extend the battery life.
In the intermittent control means 8 and 21, for example, 20 m at intervals of 30 seconds
Power is supplied to the receiving means 5 and the receiving means 18 only for a second to enter the receiving state. If it is necessary to transmit data to the other party, the radio wave is transmitted at the timing of the above-mentioned 30 second interval which is synchronized with the other party. As a radio wave to be used, a radio wave in the 400 MHz band, which has recently been approved for use as a low power radio, is used. The channel selecting means 3 and the channel selecting means 16 are for selecting the frequency of the radio wave to be transmitted and received. The channel selecting means 3 and the channel selecting means 16 have a so-called PLL (PHASE LOCKED LOOP) system configuration. Signal generating means 4 and signal generating means 17
Is a crystal oscillator and serves as a reference frequency for determining the channel frequency of the channel selecting means 3 and the channel selecting means 16. ± 4ppm by law for small power radio
It is stipulated that the following frequency accuracy is required. In order for the parent device and the child device to perform the transmission operation and the reception operation at the same time in synchronization with each other, the clock generation means 6 for determining the operation time of the intermittent control means 8 and the intermittent control means 21.
And the clock frequency of the clock generation means 19 must match without any deviation. The timer means 7 and the timer means 20 measure the intermittent operation time intervals by counting the clock pulses from the clock generating means 6 and the clock generating means 19. Generally, clock generation means 6
A crystal oscillator is used as the clock generation means 19, but the clock frequencies of the clock generation means 6 and the clock generation means 19 do not match due to the influence of temperature and the initial adjustment error. As a result, the intermittent operation timings of the two shift with time. Therefore, a signal for timing adjustment is transmitted from the parent device before the intermittent operation timing is significantly deviated. For example, if the frequency accuracy of the crystal oscillators used for the clock generating means 6 and the clock generating means 19 is ± 50 ppm, the worst case will be a deviation of ± 100 ppm between the parent device and the child device. Therefore, for example, in 10 minutes, there is a deviation of ± 60 msec. Therefore, the parent device transmits the timing adjustment signal at 10-minute intervals by slightly lengthening the preamble signal transmitted at the time of transmission so that the child device can receive the signal even if it is deviated by ± 60 msec. When the slave device receives the signal for timing adjustment from the master device, it controls the timer means 20 and corrects the start time of the timer means 20. The above operation cancels the intermittent operation timing deviation every 10 minutes, so that the intermittent operation timing deviation is not accumulated over 10 minutes or more.

[0006]

However, in the configuration of the above-mentioned conventional transmission device, the time interval at which the master device transmits the timing adjustment signal is determined by the maximum difference between the clock frequencies of the master device and the slave device. Therefore, when a normal crystal oscillator is used, it is necessary to transmit and receive the timing adjustment signal at a time interval of about 10 minutes, which causes a deterioration in battery life. Further, when a crystal oscillator with high frequency accuracy is used, the time interval can be lengthened, but there is a problem that such a high-precision crystal oscillator is very expensive.

The transmission apparatus of the present invention is intended to solve the above-mentioned problems, and an object thereof is to realize a transmission apparatus capable of extending the transmission / reception cycle of a timing adjustment signal and thereby extending the battery life.

[0008]

In order to achieve the above object, the transmission device of the present invention comprises a receiving means for receiving radio waves,
Clock generating means, timer means for measuring time based on the clock signal from the clock generating means, intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, and intermittently. The reference signal generating means, the time error detecting means for detecting a time error between the signal from the reference signal generating means and the signal from the clock generating means, and the time error detecting signal from the time error detecting means. It is configured to correct the time measurement of the timer means.

The reference signal generating means used in the above-mentioned structure receives as an input the signal from the receiving means for receiving the radio wave from the second transmission device which transmits the radio wave intermittently at a predetermined time interval. The time interval of radio waves from the second transmission device is used as an output signal.

Further, the reference signal generating means used in the above construction is also used as the signal generating means for determining the frequency to be received by the receiving means.

[0011]

With the above arrangement, the transmission device of the present invention can detect the clock frequency shift between the parent device and the child device and change the count value of the timer means in the direction of eliminating the clock frequency shift between them. Therefore, the transmission / reception interval of the timing adjustment signal can be lengthened.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1A shows the configuration of the parent device, and FIG. 1B shows the configuration of the child device. The same functional blocks as in the conventional example are given the same numbers. In FIG. 1A, 1 is an antenna, 2 is transmitting means, 3 is channel selecting means, 4 is signal generating means, 5 is receiving means, 6 is clock generating means, 7 is timer means, and 8 is intermittent control means. The transmission device 29 is configured. Reference numeral 9 is a public telephone line, 10 is a no-ringing network control means (hereinafter referred to as TN) connected to the public telephone line 9.
CU), 11 is an interface means, and
-The NCU 10 and the interface means 11 constitute the data collecting means 13.

In FIG. 1B, 14 is an antenna, 1
5 is transmitting means, 16 is channel selecting means, 17 is signal generating means, 18 is receiving means, 19 is clock generating means,
Reference numeral 20 is a timer means, and 21 is an intermittent control means, which constitute a transmission device 30. Reference numeral 22 is a gas pipe connected to the home, 23 is a gas flow meter (so-called gas meter) provided in the middle of the gas pipe 22 for measuring the amount of gas used in the target home, and 24 is a storage means. Reference numeral 26 is a reference signal generating means, and 27 is a time error detecting means.

The parent device and the child device are driven by a battery, and an intermittent reception system is adopted to extend the battery life.
That is, as in the conventional example, the timing adjustment signal is transmitted from the parent device (A) at intervals of 10 minutes. In the slave device (B), when the timing adjusting signal from the parent device (A) is received by the receiving means 18, the reference signal generating means 26 synchronizes with the timing adjusting signal based on the timing adjusting signal received by the receiving means 18. The signal is output every 10 minutes. The time error detecting means 27 measures the timing matching signal interval from the reference signal generating means 26 with the signal from the clock generating means 19. For example, it is assumed that the timing matching signal interval measured by the signal from the clock generating means 19 is 10 minutes and 10 milliseconds. Then, the time error detection means 27 outputs an error signal of 10 msec assuming that the timing adjustment signal interval is a correct 10 minute interval. This error signal controls the timer means 20 to cause the timer means 20 to generate an output every 10 minutes and 10 milliseconds in the time measurement by the signal from the clock generating means 19. Therefore, the output of the timer means 20 has the same time interval as the timing adjustment signal. Therefore, even if the time interval of the timing adjustment signal is made longer than 10 minutes, for example, about every hour, the timing of the intermittent operation of the parent device (A) and the child device (B) does not largely deviate. That is, since the transmission interval of the timing adjustment signal can be lengthened, the transmission power of the timing adjustment signal can be reduced for the parent device (A), and the child device (B) can be reduced.
Therefore, the reception power of the timing adjustment signal can be reduced. Therefore, the battery life is extended for both the parent device (A) and the child device (B).

Another embodiment of the present invention will be described with reference to FIG. 2A shows the configuration of the parent device, and FIG. 2B shows the configuration of the child device. The same functional blocks as those in the embodiment of FIG. 1 are assigned the same numbers. In FIG. 2A, 1
Is an antenna, 2 is a transmitting means, 3 is a channel selecting means,
Reference numeral 4 is a signal generating means, 5 is a receiving means, 6 is a clock generating means, 7 is a timer means, and 8 is an intermittent control means, which constitutes a transmission device 29. Reference numeral 9 is a public telephone line, 10 is a no-ringing network control unit (hereinafter referred to as T-NCU) connected to the public telephone line 9, 11 is an interface unit, and the T-NCU 10 and the interface unit 11 constitute a data collecting unit 13. is doing.

In FIG. 2B, 14 is an antenna and 1
5 is transmitting means, 16 is channel selecting means, 17 is signal generating means, 18 is receiving means, 19 is clock generating means,
Reference numeral 20 is a timer means, and 21 is an intermittent control means, which constitute a transmission device 30. Reference numeral 22 is a gas pipe connected to the home, 23 is a gas flow meter (so-called gas meter) provided in the middle of the gas pipe 22 for measuring the amount of gas used in the target home, and 24 is a storage means. 27 is a time error detection means.

The parent device and the child device are driven by batteries, and an intermittent reception system is adopted to extend the battery life.
The signal generation means 4 and the signal generation means 17 are intermittent control means 8
And the intermittent control means 21 operates intermittently. Then, the signal generating means 4 and the signal generating means 17 have frequency accuracy of ± 4.
Generates highly accurate signals below ppm. The signal frequency from the signal generating means 4 and the signal generating means 17 is compared with the signal frequency from the clock generating means 6 and the clock generating means 19 in the time error detecting means 28 and the time error detecting means 27, and the time error signal is time error. Output from the detection means 28 and the time error detection means 27. The timer means 7 and the timer means 20 are controlled by this time error signal so that the time interval measured with the frequency accuracy of the signal generating means 4 and the signal generating means 17 is reached. Therefore, the accuracy of the intermittent operation is ± 4ppm in absolute error for both the parent device (A) and the child device (B).
It becomes the following. Therefore, the time interval of the intermittent operation can be made longer than 10 minutes, for example, every hour, and the battery life can be extended.

A clock of a microcomputer may be used as the reference signal generating means.

[0019]

As described above, according to the transmission apparatus of the present invention, the receiving means for receiving the radio wave, the clock generating means, and the timer means for measuring the time based on the clock signal from the clock generating means, From the intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, the reference signal generating means operating intermittently, the signal from the reference signal generating means and the clock generating means. The time error detection means for detecting the time error of the signal of (1) and the time error detection signal from the time error detection means are configured to correct the time measurement of the timer means, so that the intermittent time interval is lengthened. This has the effect of extending the battery life.
Further, by sharing the signal generating means serving as the reference frequency of the PLL and the reference signal generating means, the absolute accuracy can be improved without increasing the number of parts.

[Brief description of drawings]

FIG. 1 is a block diagram of a transmission device and an automatic meter reading system using the same according to an embodiment of the present invention.

FIG. 2 is a block diagram of a transmission device and an automatic meter reading system using the same according to another embodiment of the present invention.

FIG. 3 is a block diagram of a conventional transmission device and an automatic meter reading system using the same.

[Description of Reference Signs] 2 transmitting means 3 channel selecting means 4 signal generating means 5 receiving means 6 clock generating means 7 timer means 8 intermittent control means 10 T-NCU 15 transmitting means 16 channel selecting means 17 signal generating means 18 receiving means 19 clock Generating means 20 Timer means 21 Intermittent control means 23 Flowmeter 24 Storage means 26 Reference signal generating means 27 Time error detecting means

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masahiro Yamamoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A receiving means for receiving a radio wave, a clock generating means, a timer means for measuring a time based on a clock signal from the clock generating means, and the reception intermittently at time intervals controlled by the timer means. Intermittent control means for controlling the operation of the means, reference signal generating means operating intermittently, time error detecting means for detecting a time error between the signal from the reference signal generating means and the signal from the clock generating means, A transmission device configured to correct the time measurement of the timer means by a time error detection signal from the time error detection means. 2. The reference signal generating means receives a signal from a receiving means for receiving a radio wave from a transmission device which intermittently transmits a radio wave at a predetermined time interval, and receives the time interval of the radio wave from the transmission device. 2. The transmission device according to claim 1, wherein is used as an output signal. 3. The transmission device according to claim 1, wherein the reference signal generating means is also used as signal generating means for determining a frequency to be received by the receiving means. 4. An automatic meter reading system comprising a master device and a slave device for data communication, wherein the master device is a data collection means for collecting measurement data of a flow meter, and a data collection request signal from the data collection means. Alternatively, it comprises a transmitting means for transmitting a response signal to the measurement data from the flowmeter by transmitting it on a carrier wave, and a receiving means for receiving the measurement data from the flowmeter, and the child device is a flowmeter and a flowmeter. Storage means for electronically storing the measurement data, transmission means for transmitting the measurement data from the storage means on a carrier wave signal, and a request signal for requesting the transmission of the measurement data from the storage means or the measurement data Receiving means for receiving a response signal for the clock signal, clock generating means, and timer means for measuring time based on the clock signal from the clock generating means. From the intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, the reference signal generating means operating intermittently, the signal from the reference signal generating means and the clock generating means. And a time error detecting means for detecting a time error of the signal, and an automatic meter reading system configured to correct the time measurement of the timer means by the time error detecting signal from the time error detecting means. 5. An automatic meter reading system comprising a master device and a slave device for data communication, wherein the master device is a data collection means for collecting measurement data of a flow meter, and a data collection request signal from the data collection means. Alternatively, transmitting means for transmitting a response signal to the measurement data from the flowmeter on a carrier wave, receiving means for receiving the measurement data from the flowmeter, clock generating means, and a clock signal from the clock generating means. Timer means for measuring time based on the above, intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, reference signal generating means for intermittent operation, and the reference signal generating means. And a time error detecting means for detecting a time error between the signal from the clock generating means and the signal from the clock generating means. The time measurement of the timer means is configured to be corrected by the time error detection signal, while the slave device includes a flow meter, a storage means for electronically storing measurement data of the flow meter, and a storage means from the storage means. An automatic meter-reading system comprising: a transmitting means for transmitting measurement data on a carrier wave signal; and a receiving means for receiving a request signal requesting transmission of the measurement data from the storage means or a response signal to the measurement data. 6. The reference signal generating means receives a signal from a receiving means for receiving a radio wave from a transmission device which intermittently transmits a radio wave at a predetermined time interval, and receives the time interval of the radio wave from the transmission device. 6. The automatic meter-reading system according to claim 4 or 5, characterized in that 7. An automatic meter reading system comprising a master device and a slave device for data communication, wherein the master device is a data collecting means for collecting measurement data of a flow meter, and a data collection request signal from the data collecting means. Alternatively, transmitting means for transmitting a response signal to the measurement data from the flowmeter on a carrier wave, receiving means for receiving the measurement data from the flowmeter, clock generating means, and a clock signal from the clock generating means. Timer means for measuring time based on the above, intermittent control means for intermittently controlling the operation of the receiving means at time intervals controlled by the timer means, reference signal generating means for intermittent operation, and the reference signal generating means. And a time error detection means for detecting a time error between the signal from the clock generation means and the signal from the clock generation means, while the slave device is a flow meter and Storage means for electronically storing the measurement data of the flow meter, transmission means for transmitting the measurement data from the storage means on a carrier wave signal, and a request signal for requesting the transmission of the measurement data from the storage means Receiving means for receiving a response signal to the measurement data, clock generating means, timer means for measuring time based on the clock signal from the clock generating means, and intermittently receiving the reception at time intervals controlled by the timer means. An intermittent control means for controlling the operation of the means, a reference signal generating means that operates intermittently, and a time error detecting means for detecting a time error between the signal from the reference signal generating means and the signal from the clock generating means. The parent device and the child device correct the time measurement of the timer means by the time error detection signal from the time error detection means. Automatic meter reading system configured to so that. 8. The automatic meter-reading system according to claim 4, 5 or 7, wherein the reference signal generating means is also used as signal generating means for determining the frequency to be received by the receiving means.