JP2003168180A - Automatic meter reading terminal device and automatic meter reading system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a conventional automatic meter reading terminal device requires re-synchronization with a public base station and waiting whenever step-out occurs between the terminal and the public base station and power consumption is increased when step-out occurs frequently. <P>SOLUTION: An error with respect to call-incoming timing of 1.2 sec with a slow clock is confirmed with a fast clock at a stage in an initial state to correspond to the call-incoming timing by the combination of the number of slow clocks and the number of fast clocks, and a call-incoming signal is received within a fast clock operation time. <P>COPYRIGHT: (C)2003,JPO

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 terminal device for transmitting collected measurement data of electricity, gas, water, etc. to a center device via a PHS public base station.

[0002]

2. Description of the Related Art FIG. 9 is a diagram showing a configuration of an automatic meter reading system using a public mode of PHS. In FIG. 9, a conventional automatic meter reading system collects data of a meter installed in each house, for example, a gas meter 1 at a meter reading terminal 2, and uses a public base station 3 for PHS public mode communication.
(A, b, ...) And the data is collected in the center device 5 which aggregates the data through the ISDN network (Integrated Service Digital Network) 4.

FIG. 10 shows a flowchart for explaining the standby operation of the meter-reading terminal 2. Hereinafter, the standby operation of the meter-reading terminal 2 will be described with reference to FIG. The public base station 3 always transmits a control signal or an incoming call signal every 100 msec, transmits the control signal once every 1.2 seconds, and sends the incoming call signal for the remaining 11 times. The meter-reading terminal 2 is
In order to detect whether there is an incoming call to itself, it is necessary to synchronize with the control signal transmission timing.

Therefore, first, the meter-reading terminal 2 receives a signal (control signal or call-in signal) transmitted from the public base station 3 every 100 msec to synchronize with the public base station 3 ( In step S10), the public base stations 3a and 3b capable of communicating with itself are detected (step S11).

Next, the meter-reading terminal 2 waits for the public base station 3a whose received signal strength is a predetermined value or more among the detected public base stations (3a, 3b) (step S12). That is, in synchronization with the transmission timing of the public base station 3a based on the synchronization in step S10, a signal transmitted by the public base station 3a is received every 100 ms until a control signal is received (step S13), and this control is performed. Which of the 11 incoming call signals has its incoming call timing registered in the signal is read (step S
14) At this timing (every 1.2 seconds), the presence or absence of an incoming call is detected (step S15). If there is an incoming call addressed to itself (step S16), an allocation request signal for having a communication channel allocated is transmitted to the public base station 3a (step S17).

The meter-reading terminal 2 is operated by the high-speed clock until the control signal is received (step S13), but the reception timing (1.2 seconds) is counted by the low-speed clock during the normal standby after the incoming call timing is detected. By doing so, the power consumption is reduced.

However, since the timing accuracy of the low-speed clock (the accuracy of the clock generation interval) is inferior to that of the high-speed clock, the synchronization with the public base station 3a is higher than that in the case where synchronization is always performed with the high-speed clock. Is frequently missed and the incoming call signal from the public base station 3a cannot be received frequently. When the control signal from the public base station 3a cannot be received (step S15), the public base station search (step S11), standby (step S12), and control are performed again by synchronization with the high-speed clock (step S10). The operation (open search) up to signal reception (step S13) has to be performed, resulting in an increase in power consumption.

[0008]

Since the conventional automatic meter-reading terminal device is constructed and operates as described above, when synchronization with the public base station is lost, synchronization with the public base station is reestablished each time. Therefore, there is a problem that power consumption becomes large if out of synchronization occurs frequently.

The present invention has been made to solve the above problems, and reduces the frequency of out-of-synchronization occurring in communication between an automatic meter-reading terminal and a public base station. The purpose is to obtain an automatic meter reading system and an automatic meter reading terminal device that can reduce power consumption.

[0010]

An automatic meter reading system according to the present invention is a second generation cordless telephone system (PHS).
In the automatic meter reading system that uses the public line communication of the above, the automatic meter reading terminal transmits the measured value data of the meters of electricity, gas, water, etc. to the center device via the public base station. A high-speed clock circuit for generating a clock, a low-speed clock circuit for generating a low-speed clock having a clock interval longer than the high-speed clock, a counter for counting the number of clocks of the low-speed clock and the high-speed clock, and a public base station The control unit includes a synchronization detection unit that detects synchronization with an incoming call signal transmitted at a predetermined timing (1.2 second intervals), and a control unit that controls driving of the high-speed clock circuit and the low-speed clock circuit. An error detection unit that counts a predetermined number of the low speed clocks by the high speed clocks to detect an error of the low speed clocks; A synchronization timing determination unit that determines the usage time (first time) of the low-speed clock circuit and the usage time (second time) of the high-speed clock circuit between the incoming signal timings based on the error detected by the detection unit. And have.

The automatic meter-reading terminal according to the present invention utilizes the public line communication of the second-generation cordless telephone system (PHS), and transmits the measured value data of meters such as electricity, gas, and water through a public base station. In an automatic meter-reading terminal device that transmits to a center device, a high-speed clock circuit that generates a high-speed clock, a low-speed clock circuit that generates a low-speed clock whose clock interval is longer than the high-speed clock, the low-speed clock and the number of clocks of the high-speed clock are set. A counter for counting, a synchronization detector for detecting synchronization with an incoming call signal transmitted from the public base station at a predetermined timing (at intervals of 1.2 seconds), and driving of a high-speed clock circuit and a low-speed clock circuit. And a control unit for controlling, wherein the control unit counts a predetermined number of the low-speed clocks by the high-speed clocks and lowers them. An error detection unit that detects an error in the clock, and a usage time (first time) of the low-speed clock circuit and a usage time of the high-speed clock circuit between the incoming call signal timings based on the error detected by the error detection unit. And a synchronization timing determination unit that determines (second time).

The second time may be set shorter than the low-speed clock generation interval.

Further, the incoming call signal transmitted from the public base station at a predetermined timing (at intervals of 1.2 seconds) may be counted by the high speed clock, and this count value may be set as the synchronization timing.

Further, a temperature sensor is provided, and the error detection unit obtains an error when the temperature change per hour of the automatic meter-reading terminal itself exceeds a predetermined value or when the temperature exceeds a predetermined value. May be.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 of the Invention FIG. 1 is a block diagram showing the configuration of an automatic meter-reading terminal according to Embodiment 1 of the present invention. In FIG. 1, the automatic meter-reading terminal 2 is
An RF unit 11 for transmitting and receiving signals, a demodulation unit 12 for demodulating signals, a synchronization detection unit 13 for detecting synchronization, a clock counter 14, a control unit 15 including an error detection unit 15a and a synchronization timing determination unit 15b, It comprises a low-speed clock circuit 16, a high-speed clock circuit 17, and a battery 18 which supplies power to these.

In the initial state where the automatic meter-reading terminal 2 is not synchronized with the public base station 3 such as when the power is turned on, the automatic meter-reading terminal 2 performs reception in synchronization with the control signal transmission timing of the public base station 3. As in the conventional case, the flow from step S10 to step S14 shown in FIG. 10 is awaited based on the high-speed clock.

FIG. 2 is a diagram for explaining the error α between the low speed clock and the incoming call timing. The incoming call timing of 1.2 seconds is L (for example, 500) clocks in the low-speed clock, and the high-speed clock is N times (for example, 200 times) the low-speed clock. L generated by the low-speed clock circuit 16
An error between each clock and the incoming call timing of 1.2 seconds will be described as α.

In FIG. 2, (a) shows the case where L pieces of the low-speed clock are accumulated faster than the incoming call timing, and the addition of the error α is required for correction, and (b) shows the case where the L pieces of the low-speed clock are accumulated. This shows a case where the correction is required to be deleted by the error α, which is later than the incoming call timing. The rising edge of the pulse is one clock, and the number of low-speed clock pulses from the incoming call timing is shown in [].

The error detection unit 15a of the meter-reading terminal 2 detects the accuracy of the low-speed clock by the high-speed clock at the standby stage based on the high-speed clock, and obtains the error from the incoming call timing and its correction value.

FIG. 3 shows a flowchart for setting the correction value for the incoming call timing using the error α according to the first embodiment of the present invention. Here, the number of low-speed clocks generated in 1.2 seconds is L, and the number of high-speed clocks is N times the number of low-speed clocks. The L clocks actually generated from the low-speed clock circuit 16 and the incoming call timing 1.2. The error from the second will be described as α.

The automatic meter-reading terminal 2 drives both the low-speed clock circuit 16 and the high-speed clock circuit 17 during the period from the synchronization of the initial state to the stand-by, and the incoming call timing 1.
From the number of low-speed clocks generated in 2 seconds, the number of low-speed equivalent K (= L ×)
N) and a high-speed equivalent number T which is the number of high-speed clocks corresponding to the incoming call timing of 1.2 seconds. (Step S2
0).

The synchronization timing determination unit 15b subtracts the high speed equivalent number T from the low speed equivalent number K to obtain the error α (step S21). Next, whether the error α is positive or negative is determined (step S22). When the error α is negative, the number of low-speed clocks is L (step S24), and the number of high-speed clocks is | α |
Individual pieces (step S26). That is, the incoming call timing of 1.2 seconds is set to L low-speed clocks + high-speed clocks | α |. When the error α is positive, the number of low-speed clocks is (L-1) (step S30), and the number of high-speed clocks is (N-α) (step S32). That is, the incoming call timing of 1.2 seconds is set to low speed clocks (L-1) + high speed clocks (N-α).

By the above flow, the clock correction value for the incoming call timing is obtained at the initial synchronization. In step S20, the accuracy can be improved by performing the measurement with the high-speed clock a plurality of times and obtaining K by the average value or moving average thereof.

Further, in step S28, it is also possible to issue a regular adjustment such as once a day, or to issue an adjustment command corresponding to the occurrence of loss of synchronization.

FIG. 4 is a diagram for explaining the operation of the low speed and high speed clocks in the standby operation of the automatic meter-reading terminal 2 according to the first embodiment of the present invention. In FIG.
(A) shows switching between use of a low speed clock and a high speed clock, 31 is a low speed clock use time, 32 is a high speed clock use time, 33 is a switching point from a low speed clock to a high speed clock, 34 is a high speed clock to a low speed This is the switching point to the clock.

FIG. 4B shows the driving state of the low speed clock circuit. In the figure, the low-speed clock circuit is always operating. FIG. 4C shows the driving state of the high speed clock. _VL is the drive voltage of the low-speed clock circuit,
V _H is a drive voltage for the high speed clock circuit.

In FIG. 4A, the low-speed clock use time 31 is the correction value L or (L-
1) The quantity. That is, the switching point 33 to the high-speed clock use time 32 is α or (N
It is set so that it can be switched to the high-speed clock by -α). In FIG. 4B, the low speed clock circuit is always operating as described above. In FIG. 4 (c), the high-speed clock circuit is driven at a t _V point earlier than the switching point 33 for a period of time after the drive voltage is applied to the circuit until its oscillation stabilizes, and the pulse width is 0.5 nsec. It is driven several tens of times for receiving the incoming call signal, for example, 10 m seconds, and the driving is finished at the point t _E. This point t _E is the switching point 34 from the high speed clock to the low speed clock in FIG.
Becomes The high-speed clock operating time is 10 times as described above.
The time is not limited to m seconds and may be set appropriately.

As described above, the first embodiment of the present invention
In the initial state, the automatic meter reading terminal confirms the error with respect to the incoming call timing 1.2 seconds at the low speed clock by the high speed clock, and adjusts to the incoming call timing by combining the number of low speed clocks and the number of high speed clocks. Since the incoming signal is received within the high-speed clock operation time, out-of-sync is less likely to occur, and the number of re-synchronization works by the high-speed clock due to out-of-sync can be reduced, so that increase in power consumption can be suppressed. Further, since the high-speed clock operating time for each incoming call timing is set as short as about 10 msec, the power consumption can be suppressed also by this.

Second Embodiment of the Invention Although the first embodiment of the invention has been described on the premise that the rising edge of the low-speed clock coincides with the incoming call timing, the rising edge of the low-speed clock may be deviated. Figure 5
The case where the rising edge of the first pulse of the low-speed clock with respect to the incoming call timing is deviated is shown in FIG.

The example of FIG. 5A has the same deviation α (<0) as that of FIG. 2A, but when the first pulse of the low-speed clock is delayed by β high-speed clocks from the incoming call timing, in other words, The case where the incoming call timing precedes the first pulse of the low-speed clock by β high-speed clocks is shown. Furthermore | α
This is a case where | is larger than β and the incoming call timing comes after the Lth low-speed clock.

FIG. 5B shows the first low speed clock.
This is a case where the pulse is delayed by β high-speed clocks to the incoming call timing, but | α | is smaller than β, and the incoming call timing comes before the Lth low-speed clock.

FIG. 5C shows the same deviation α as FIG. 2B.
In (≧ 0), the first pulse of the low-speed clock is delayed from the incoming call timing by β high-speed clocks, and the incoming call timing comes before the Lth low-speed clock.

FIG. 5D shows a case where both α and β have a shift of more than half of one low-speed clock pulse and the incoming call timing reaches to the low-speed clock L-1.

FIG. 6 shows a flowchart for setting the correction value for the incoming call timing using the errors β and α according to the second embodiment of the present invention. Error detector 15a
Prior to this, the error α is obtained in the flowchart of FIG. 3 (step S21). Next, the error β is detected by the high speed clock (step S40).

The synchronization timing determination unit 15b then determines whether the error α obtained above is positive or negative (step S42), and α
Is negative, the process proceeds to step S44, and it is determined whether (| α | -β) is positive or negative (step S44).

In step S44, (| α | -β)
If is positive or zero, the process proceeds to step S46, where the number of low-speed clocks is L and the number of high-speed clocks is (| α | -β). If (| α | -β) is negative, the process proceeds to step S48, where the low-speed clock count is (L-1) and the high-speed clock count is (N + | α | -β).

If α is positive or zero in step S42, the process proceeds to step S50, where (N- | α | -β).
Judge the sign of.

In step S50, (N- | α |-
If β) is positive or zero, the process proceeds to step S52,
The number of low-speed clocks is (L-1) and the number of high-speed clocks is (N-
α-β). When (N- | α | -β) is negative, the process proceeds to step S54, where the low-speed clock number is (L-2) and the high-speed clock number is (2N-α-β).

As described above, since the time from the first rising of the low-speed clock to the next incoming call timing is matched by the combination of each low-speed clock and the high-speed clock, the out-of-synchronization is less likely to occur and the synchronization is reduced. Since the number of times of resynchronization work by the high-speed clock due to disconnection can be reduced, increase in power consumption can be suppressed. Further, since the high-speed clock operating time for each incoming call timing is set as short as about 10 msec, the power consumption can be suppressed also by this.

In the first and second embodiments described above, the high-speed clock circuit 17 calculates the incoming call timing interval of 1.2 seconds, but it is transmitted from the public base station 3 (3a) every 100 milliseconds. Signal, that is, the control signal or the incoming signal to the self every 12 times is considered as 1.2 seconds and measured with a high-speed clock, and the count value of the high-speed clock is a low speed of 1.2 seconds. You may make it set as the considerable number K.

Third Embodiment of the Invention FIG. 7 is a block diagram showing the configuration of the automatic meter-reading terminal according to the third embodiment of the present invention. In FIG. 7, the automatic meter-reading terminal 2 includes an RF unit 11 that transmits and receives a signal, a demodulation unit 12 that demodulates the signal,
A synchronization detector 13 for detecting synchronization and a clock counter 1
4, error detection unit 15a, synchronization timing determination unit 15b
A control unit 15 including the following, a low-speed clock circuit 16, a high-speed clock circuit 17, a battery 18 for supplying power to these,
It is composed of a built-in temperature sensor 19.

FIG. 8 shows a flowchart for setting the correction value for the incoming call timing using the error α according to the third embodiment of the present invention. After obtaining the number of low-speed clocks and the number of high-speed clocks as in the first embodiment, step S34
The temperature sensor 19 causes the control unit 15 to issue an adjustment command (step S36) when the temperature change of the meter itself per hour exceeds a predetermined value or when the temperature of the meter itself exceeds a predetermined value. It is what

As a result, the adjustment command is issued even when there is a temperature change, an abnormally high temperature, or a low temperature that greatly affects the accuracy of the clock, so that the synchronization corresponding to the external conditions can be achieved and the high-speed clock drive It is possible to suppress power consumption without causing frequent synchronization operations due to.

[0044]

The automatic meter-reading terminal and the automatic meter-reading system according to the present invention confirm the error between the low-speed clock and the incoming call timing of 1.2 seconds by the high-speed clock in the initial state, and confirm the number of low-speed clocks and the high-speed clock Since the incoming signal is received within the high-speed clock operation time by matching the incoming call timing by combining the numbers, out-of-sync is less likely to occur, and the number of re-synchronization work with the high-speed clock due to out-of-sync can be reduced. Therefore, increase in power consumption can be suppressed.

Furthermore, by providing a temperature sensor,
When the temperature change per hour of the meter itself exceeds a specified value,
Alternatively, when the temperature of the meter itself exceeds a predetermined value, an adjustment command is issued so that synchronization deviation due to temperature conditions can be dealt with, so that power consumption can be suppressed without causing frequent synchronization operations by high-speed clock driving. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an automatic meter-reading terminal according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining an error α between a low speed clock and an incoming call timing.

FIG. 3 is a flowchart for setting a correction value for an incoming call timing using an error α according to the first embodiment of the present invention.

FIG. 4 is a diagram for explaining operations of a low speed clock and a high speed clock in a standby operation of the automatic meter-reading terminal according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a case where the rising edge of the first pulse of the low-speed clock is deviated from the incoming call timing according to the second embodiment of the present invention.

FIG. 6 is a flowchart for setting a correction value for an incoming call timing using the errors β and α according to the second embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of an automatic meter-reading terminal device according to a third embodiment of the present invention.

FIG. 8 is a flowchart for setting a correction value for an incoming call timing using an error α according to the third embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of an automatic meter reading system using a conventional PHS public mode.

FIG. 10 is a flowchart illustrating a standby operation of a conventional meter-reading terminal.

[Explanation of symbols]

1 meter, 2 meter terminal,
3 public base stations, 4 ISDN networks, 5
Center device, 11 RF unit, 12 demodulation unit, 13 synchronization detection unit, 14 counter,
15 control unit, 15a error detection unit,
15b synchronization timing determination unit, 16 low speed clock circuit, 17 high speed clock circuit, 18 battery,
19 Temperature sensor, 30 Incoming call timing, 31
Low-speed clock usage time, 32 High-speed clock usage time, 33 switching points, 34 switching points.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2F073 AA07 AA08 AA09 AB04 BB01                       BB20 BC02 CC05 CC11 DE12                       DE17 GG01 GG07 GG08                 5K067 AA21 BB04 BB21 DD51 EE02                       EE10 EE16 FF02 GG01                 5K101 KK12 LL11

Claims (5)

[Claims] 1. A second generation cordless telephone system (PH
In the automatic meter reading system that uses S) of public line communication to transmit the measured value data of meters such as electricity, gas, and water to the center device via the public base station, the automatic meter reading terminal A high-speed clock circuit for generating a high-speed clock, a low-speed clock circuit for generating a low-speed clock having a clock interval longer than the high-speed clock, a counter for counting the number of clocks of the low-speed clock and the high-speed clock, and the public base station A synchronization detection unit for detecting synchronization with an incoming call signal transmitted at a predetermined timing (at an interval of 1.2 seconds), and a control unit for controlling driving of the high-speed clock circuit and the low-speed clock circuit. The unit counts a predetermined number of the low-speed clocks with the high-speed clocks and detects an error of the low-speed clocks. A synchronization for determining the usage time (first time) of the low-speed clock circuit and the usage time (second time) of the high-speed clock circuit between the incoming call signal timings based on the error detected by the error detection unit An automatic meter-reading system having a timing determination unit. 2. A second generation cordless telephone system (PH
In the automatic meter-reading terminal device that uses the public line communication of S) to transmit the measured value data of meters of electricity, gas, water, etc. to the center device via the public base station, and a high-speed clock circuit that generates a high-speed clock. A low-speed clock circuit that generates a low-speed clock whose clock interval is longer than the high-speed clock, a counter that counts the number of clocks of the low-speed clock and the high-speed clock, and a predetermined timing (1.2 seconds) from the public base station. A synchronization detection unit that detects synchronization with an incoming call signal transmitted at an interval), and a control unit that controls driving of a high-speed clock circuit and a low-speed clock circuit, wherein the control unit sets a predetermined number of the low-speed clocks. An error detection unit that counts by the high-speed clock to detect an error of the low-speed clock, and an error detected by the error detection unit. Based on the use time of the low-speed clock circuit between incoming signal timing (the first time), high speed clock circuit operating time (second
And a synchronization timing determining unit that determines the time). 3. The automatic meter-reading terminal according to claim 2, wherein the second time is set shorter than the low-speed clock generation interval. 4. An incoming call signal transmitted from a public base station at a predetermined timing (at intervals of 1.2 seconds) is counted by a high-speed clock, and this count value is set as a synchronization timing. The automatic meter-reading terminal according to claim 2 or 3. 5. An error detection unit having a temperature sensor, wherein the error detection unit obtains an error when the temperature change per hour of the automatic meter-reading terminal itself exceeds a predetermined value or when the temperature exceeds a predetermined value. It has done, The automatic meter-reading terminal in any one of Claims 2-4.