JP2001256583A - Automatic meter reading system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably perform communication between a master station and slave stations all the time in an automatic meter reading system where synchronous communications by an intermittent reception system between the master station and slave stations to which a meter device is connected. SOLUTION: This automatic meter reading system has a headquarters station, the radio master station capable of communicating with the headquarters station by radio, the radio slave stations capable of communicating with the radio master station by radio and a meter device capable of communicating with the radio slave stations by radio, and supplies response data of meter reading data, etc., of the meter device to the headquarters station via the radio slave stations and the radio master station in response to a request signal of meter reading, etc., from the headquarters station. Synchronous communications are performed between the radio master station 12 and the radio slave stations 8(1) and 8(2), and the synchronous correction of receiving timing T between the station 12 and the stations 8(1) and 8(2) is also performed in such a manner that the station 12 periodically performs synchronous correction communications D consisting of continuous data communications D1 and synchronous correction information Dt to the stations 8(1) and 8(2).

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 that can automatically measure the amount of gas, water, electricity, etc. used via a communication line. More specifically, the meter reading result of the meter device for measuring the usage of gas, water, electricity, etc. is supplied from the wireless slave station to the wireless master station by wireless communication,
The present invention relates to an automatic meter reading system for transferring data from the wireless master station to a head office via a public telephone line or the like.

[0002]

2. Description of the Related Art As an automatic meter reading system capable of automatically measuring the usage of gas, water, electricity, etc. via a communication line, it is installed in houses, factories, etc. where gas, water, electricity, etc. are consumed. A plurality of meter devices, a wireless slave station connected to each meter device, a wireless master station that collects meter reading results of each meter device by wireless communication from each wireless slave station, and a meter reading collected by the master station. There is known a configuration having a headquarters office that receives the result via a communication line.

[0003] In this case, since each wireless slave station is mounted near the installation place of the corresponding meter device, an AC commercial power supply cannot be used in many cases. Therefore, a battery is provided as a power supply and its power consumption is suppressed. This is very important. From the viewpoint of suppressing such power consumption, the wireless communication between the wireless master station and the wireless slave station in the automatic meter reading system generally employs an intermittent reception method. As a wireless communication using the intermittent reception method, an asynchronous method and a synchronous method are known.

[0004] In wireless communication based on the asynchronous system, as shown in FIG. 8, a wireless transmitting station performing a transmitting operation performs continuous data communication D1 having a time width Ta equal to or longer than an intermittent reception interval, and detects each of the carriers by intermittent reception. The receiving stations 1 and 2 transition to the receiving state at the timing of each station. After all the receiving stations 1 and 2 in the system have shifted to the receivable state, the data transmission operation of the transmitting station starts. This enables wireless section communication from the transmitting station operating asynchronously to each receiving station.

[0005] On the other hand, in the radio communication using the synchronous system, as shown in FIG. 9, a transmitting station that performs a transmitting operation between a radio transmitting station and each of the radio receiving stations 1 and 2 performs reception synchronization timing. The continuous data communication D1 is performed in accordance with T (T1, T2, T3,...), And the receiving stations 1 and 2 simultaneously transition to the receiving state, thereby enabling wireless communication from the transmitting station to the receiving station. .

[0006]

However, a conventional automatic meter reading system in which meter reading data and the like of a meter device connected to a wireless slave station is collected by a wireless master station by wireless communication is as follows. There are important issues to be solved.

First, in the former system employing the asynchronous wireless communication, the continuous data communication time must be longer than the intermittent reception time between the wireless master station and the wireless slave station. For this reason, there is a problem that the effect of reducing power consumption is poor and the response is slow.

[0008] In the latter system employing the synchronous wireless communication, the continuous data communication time is shorter than the asynchronous system in accordance with the intermittent reception timing, so that there is an advantage that the power consumption is small. It is necessary to keep the same intermittent reception timing of all wireless master stations and wireless slave stations in a wireless section. There is a problem that a wireless receiving station that is out of the receiving timing cannot perform a normal wireless receiving operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic meter reading system for performing intermittent wireless communication between a wireless master station and a wireless slave station in a synchronous manner by preventing a shift in reception timing between the wireless master station and the wireless slave station to ensure reliable reception. To enable communication.

[0010]

In order to solve the above problems, the present invention provides a head office, a radio base station capable of communicating with the head office, and a radio base station between the head office and the radio base station. A communication-capable wireless slave station, and a meter device capable of communicating with the wireless slave station, and responding to a request signal such as meter reading from the headquarters station, and responding to meter reading data or the like of the meter device. In an automatic meter reading system in which data is supplied to the headquarters station via the wireless slave station and the wireless master station, while performing synchronous communication between the wireless master station and the wireless slave station, during the synchronous communication, It is characterized in that the reception timing between the wireless master station and the wireless slave station is synchronously corrected.

Here, the synchronization correction of the reception timing between the wireless master station and the wireless slave station is performed by periodically performing the synchronization correction communication between the wireless master station and the wireless slave station. Can be.

In this case, it is desirable to repeat the synchronization correction communication a plurality of times at regular intervals in one synchronization correction communication so that the synchronization correction communication is reliably received at the wireless slave station side.

Alternatively, in one synchronization correction communication, the synchronization correction communication may be continuously repeated a plurality of times.

Next, it is desirable that the wireless master station confirms a response from one wireless slave unit during one synchronization correction communication. In this case, when a plurality of wireless slave stations are assigned to one wireless master station, the wireless master station responds to the synchronization correction communication from the sequentially different wireless slave stations. Should be checked.

[0015] On the other hand, when recognizing that the reception of the synchronization correction communication has failed, the wireless slave unit performs the following processing in a time width including a time zone in which the next synchronization correction communication is performed.
It is desirable to shift to the continuous reception state or to the intermittent reception state in a short cycle. By doing so, it is possible to reliably receive the next synchronization correction communication and correct the reception timing deviation.

When the wireless slave confirms that the reception of the synchronization correction communication has failed, the wireless slave notifies the wireless master of the fact, and the wireless master re-executes the synchronization correction communication. It may be performed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic meter reading system to which the present invention is applied will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of the automatic meter reading system of the present embodiment, and has basically the same configuration as a general automatic meter reading system for electricity, gas and water. That is, the automatic meter reading system 1 is connected via the public telephone network 4 to the head office 3 which is an administrator side system in which the central collection device 2 for collecting meter reading data and the like is installed. , A consumer-side system 5 for electricity, gas, water and the like.

The consumer side system 5 is installed in, for example, an apartment house, a factory, etc., and usually has one master station 6 and
A plurality of meter devices 7 (7
(1), 7 (2), 7 (3)... 7 (n)) connected to the slave stations 8 (8 (1), 8 (2), 8), respectively.
(3)... 8 (n)) (n is a positive integer). The master station 6 has a public telephone network 3 with the head office 2.
A transmission device 11 for communicating via a general line, a PHS line, a mobile phone network, or the like, and a wireless master station 12 for communicating with each slave station 8 are provided. Each slave station 8 is a wireless slave station, and supplies meter reading data and the like of the meter device 7 to the wireless master station 12 by wireless communication (specific low-power wireless, PHS, etc.).

FIG. 2 is a schematic block diagram of a wireless master station and slave stations. The wireless master station 12 is mainly configured by a microcomputer, and realizes various functions such as an intermittent reception control unit 21, a transmission control unit 22, and an intermittent reception timing generation unit 23 by executing a control program stored in advance. Is done. These intermittent reception control unit 21 and transmission control unit 22
Under the control of, the transmission / reception circuit 25 connected via the interface 24 is driven and controlled, various data are transmitted / received to / from each slave station 8 by wireless communication, and the received data and the like are stored in the memory 26. It is memorized. Further, a synchronization correction information generation unit 28 is provided, and here, information for correcting the reception timing of each wireless slave station 8 so as to be synchronized is generated. The wireless master station 12 having this configuration is connected to the transmission device 11 via the interface 27,
Communication with the head office 3 is performed via the transmission device 11.

Similarly, the slave station 8 is also configured mainly by a microcomputer, has an intermittent reception control unit 31, a transmission control unit 32, an intermittent reception timing generation unit 33, and a memory 36, and is connected via an interface 34. The transmission / reception circuit 35 is driven and controlled by the intermittent reception control unit 31 and the transmission control unit 32. Also, based on the synchronization correction information supplied from the wireless master station 12, the intermittent reception timing generation unit 3
3 is provided with a synchronization timing correction unit 38 for correcting the reception timing generated in Step 3.

The wireless slave station 8 having this configuration is connected to the meter device 7 via the interface 37. The meter device 7 is, for example, an electronic gas meter whose measuring section is connected to a gas pipe, detects the flow rate of gas flowing therethrough, and detects the integrated value and the like.

In the thus configured automatic meter reading system 1 of the present embodiment, the wireless communication section between the wireless master station 12 and each wireless slave station 8 uses a wireless communication system using an intermittent reception system in order to reduce power consumption. Communication takes place. Explaining also with reference to the timing chart of FIG. 3, the intermittent reception timing generation units 23 and 33 receive reception timings T (T1, T2, T3...) At fixed intervals as shown in FIGS.
..) are generated, and the state is intermittently switched to the receivable state at a cycle defined by the.

In this example, wireless communication is performed by a synchronous method. As shown in FIG. 3A, a transmitting station that performs a transmitting operation, for example, the wireless master station 12 receives a signal at a reception timing ( In accordance with FIGS. 3B and 3C), continuous data communication D1 is performed, and data D to be transmitted continuously is transmitted.
a is transmitted. When the receiving station, for example, each of the slave stations 8 (1) and 8 (2) receives the continuous data communication D1 at the reception timing T, it shifts to the receiving state and receives the data Da sent from the wireless master station 12.

Here, the wireless master station 12 and the wireless slave station 8 of the present embodiment.
During the wireless communication during the communication, during the communication from the wireless master station 12 to each wireless slave station 8, the synchronization correction information Dt of the reception timing is added after the transmission data Da, and this synchronization correction information Dt is transmitted to each slave station. 8 is transmitted. When each of the slave stations 8 receives the synchronization correction information Dt, the synchronization timing correction section 38 receives the reception timing T (T1, T2, T3,...) Generated by the reception timing generation section 33 based on the received synchronization correction information Dt.・ ・) Is corrected. Since the correction of the reception timing T is performed in each wireless slave station 8, it is possible to always synchronize the reception timing between the wireless slave stations.

Here, as a correction method for synchronizing the reception timings of the respective wireless slave stations 8, instead of adding the synchronization correction information Dt to the transmission data Da and transmitting it as described above, or together with the method. Alternatively, the timing may be adjusted by performing synchronization correction communication for periodically transmitting the synchronization correction information Dt.

For example, as shown in the timing chart of FIG. 4, the wireless master station 12 performs the synchronization correction communication D having a data configuration in which the synchronization correction information Dt is added to the continuous data communication D1 every 24 hours. (FIG. 4A). In each of the wireless slave stations, for example, the wireless slave stations 8 (1) and 8 (2),
As shown in FIGS. 4B and 4C, when receiving the continuous data communication D1 at its own reception timing T, it shifts to the reception state and receives the subsequently transmitted synchronization correction information Dt. Upon receiving the synchronization correction information Dt, the synchronization timing correction unit 38 determines whether or not the reception timing generated by the reception timing generation unit 33 is shifted. Control to correct the deviation.

Next, as a form of such periodic synchronization correction communication, it is desirable to perform a plurality of pre-synchronization correction communication prior to the synchronization correction communication during one synchronization correction communication. Referring to FIG. 5, 2 in FIG.
At the time of synchronization adjustment (at the time of synchronization correction communication) performed every four hours (one day), for example, three times of communication D before synchronization correction (previous 3),
D (previous 2) and D (previous 1) are performed in accordance with the reception timing T. These pre-synchronization correction communications include synchronization correction information D
Synchronization timing estimation information Dt1 capable of estimating the synchronization timing by t is included.

For example, as shown in FIG. 5B, even if the reception timing T1 of the wireless slave station 8 (1) is shifted and the reception of the first pre-synchronization communication D (previous 3) fails,
Assuming that the pre-synchronization communication D (previous 2) can be received at the next reception timing T2, the synchronization correction information Dt included in the next synchronization correction communication D is based on the synchronization timing estimation information Dt2 included therein. , The reception timing correction can be estimated, and the reception timing T can be corrected based on the estimation. Of course, if the synchronization correction communication D supplied thereafter can be received, the reception timing correction is performed again based on the normal synchronization correction information Dt included in the communication D.

On the other hand, as shown in FIG.
In the wireless slave station 8 (2), the first communication D before synchronization correction is performed.
If only (previous 3) can be received, the reception timing is corrected by estimating the reception timing correction based on the synchronization correction information Dt based on the synchronization correction information Dt3 included in the communication.

Here, instead of repeating the synchronization correction communication at a fixed interval as described above, the synchronization correction communication may be repeated a plurality of times (continuous transmission). Explaining with reference to the timing chart of FIG.
2, the synchronization correction communication D periodically, for example, every 24 hours.
However, the synchronization correction communication D includes first to third synchronization correction communication D (1) to D (3).
Each synchronization correction communication D (1) to D (3) is
It is composed of continuous data communication D1 and synchronization correction information Dt1, continuous data communication D1 and synchronization correction information Dt2, continuous data communication D1 and synchronization correction information Dt3.

The subsequent synchronization correction information Dt2 and Dt3 are synchronization correction timing data including a time lag with respect to the synchronization correction information Dt1 according to the transmission timing. Accordingly, even when the first slave station 8 (1) receives the first synchronization correction information Dt1 as shown in FIG. 6B, the first slave station 8 (2) receives the first synchronization correction information Dt1 as shown in FIG. 6C. Even when the second synchronization correction information Dt2 is received, the reception timing can be corrected at the same timing.

Next, in order for the wireless master station 12 to be able to identify which of the wireless slave stations 8 are synchronized and which are out of synchronization,
A response from the wireless slave device 8 that has received the synchronization correction information may be confirmed by the wireless master device 12. In this case, when a plurality of slave units 8 are provided, the response of the wireless slave unit 8 may be confirmed in a predetermined order for each synchronization correction communication.

On the other hand, if the reception of the synchronization correction communication fails, it is desirable that each of the wireless slave units 8 operate as follows so that the next synchronization correction communication can be reliably received.

Referring to the timing chart of FIG. 7, it is assumed that the wireless slave 8 (1) can receive the synchronization correction communication D, and the wireless slave 8 (2) fails to receive the synchronization correction communication D. In this case, a time (reception time zone) at which the synchronization correction communication D is performed is set in advance in each wireless slave device 8. If the synchronization correction communication D is not received at this time, the reception of the synchronization correction communication D is performed. Is determined to have failed.

The radio personal station 8 (2), which has determined that the reception of the synchronization correction communication D has failed, sets the reception time period during which the next synchronization correction communication is to be performed, during the time period including the time period. The intermittent reception method is temporarily interrupted, and a transition is made to the continuous reception state so that the synchronization correction communication can be reliably received. Alternatively, in the reception time zone, the continuous data communication D
1 is shifted to an intermittent reception state having a short receivable period, so that the synchronization correction communication d can be reliably received.

Here, as described above, when a time zone for receiving the synchronization correction communication is set in the wireless slave station 8, in other words, when the reception timing of the synchronization correction communication can be predicted, the time zone is set. In the case where the synchronization correction communication cannot be received, it can be determined that the synchronization has been lost. In this case, the wireless master station 12 is notified by performing continuous data communication for the intermittent reception time or longer.
, The synchronization correction communication is performed again, and the synchronization correction can be performed again.

The present invention is not limited to the above embodiment. For example, the communication data communicated in the automatic meter reading system according to the present invention is not limited to the types and data structures shown in the above example, but can be changed, added, or modified as appropriate. The synchronization timing may be realized by, for example, providing a clock function in the wireless slave device, or by using a counter. Furthermore, it can also be obtained from a clock of a meter or a host device. In addition, any known circuit may be employed. Furthermore, the operating frequency of the wireless line can be defined to any frequency. Further, it is possible to construct not only a wireless line using a single frequency but also a wireless line using a multi-channel access method.

[0039]

As described above, according to the automatic meter reading system of the present invention, the radio communication between the radio base station and the radio slave station is performed by the synchronous intermittent reception method, and the reception timing between the radio base station and the radio slave station is performed. Are corrected each time data is transmitted or periodically so that the values always match.

Therefore, according to the present invention, it is possible to realize an automatic meter reading system which is power saving type and can perform wireless communication reliably.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an automatic meter reading system to which the present invention is applied.

FIG. 2 is a schematic functional block diagram of a wireless master station and a wireless slave station in the automatic meter reading system of FIG.

FIG. 3 is a timing chart for explaining a reception timing synchronization correction operation performed between a wireless master station and a wireless slave station in the automatic meter reading system of FIG. 1;

FIG. 4 is a timing chart for explaining another example of the operation of correcting the synchronization of the reception timing shown in FIG. 3;

FIG. 5 is a timing chart for explaining a modification of the synchronization correction of the reception timing shown in FIG. 4;

FIG. 6 is a timing chart for explaining a modification of the synchronization correction of the reception timing shown in FIG. 4;

FIG. 7 is a timing chart for explaining still another example of the reception timing synchronization correction operation shown in FIG. 3;

FIG. 8 is a timing chart showing an intermittent reception operation by an asynchronous system in conventional wireless communication.

FIG. 9 is a timing chart showing an intermittent reception operation by a synchronization method in conventional wireless communication.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic meter-reading system 2 Central collection device 3 Head office 4 Public telephone line 5 Consumer system 6 Parent station 7 Meter device 8 Wireless child station 11 Transmission device 12 Wireless parent station 21, 31 Intermittent reception control part 22, 32 Transmission control part 23, 33 Reception timing generation unit 25, 35 Transmission / reception circuit 28 Synchronization correction information generation unit 38 Synchronization timing correction unit D, D (1), D (2), D (3) Synchronization correction communication D (previous 3), D ( 2), D (1) Communication before synchronization correction Dt, Dt1, Dt2, Dt3 Synchronization correction information D1 Continuous data communication

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F073 AA07 AA08 AA09 AB02 AB03 AB05 BB01 BB09 BC02 CC10 DD02 GG01 GG07 5K048 AA06 BA35 DA02 DB01 DC01 DC07 EB04 EB10 HA01 HA02 5K067 AA33 BB27 CC22 DD25 EE02H05H01H01 EE02H05 KK12 LL01 LL11

Claims (8)

[Claims] 1. A headquarters station, a radio base station capable of communication with the headquarters station, a radio base station capable of radio communication with the radio base station, and communication between the radio base station A possible meter device, and in response to a request signal such as meter reading from the head office, response data such as meter reading data of the meter device is transmitted to the head office via the wireless slave station and the wireless master station. In the automatic meter reading system, the synchronous communication is performed between the wireless master station and the wireless slave station, and the synchronization correction of the reception timing between the wireless master station and the wireless slave station is performed during the synchronous communication. Automatic meter reading system characterized by performing. 2. The synchronization of reception timing between the wireless master station and the wireless slave station according to claim 1, wherein synchronization correction communication is periodically performed between the wireless master station and the wireless slave station. An automatic meter reading system that performs correction. 3. The automatic meter reading system according to claim 2, wherein in one synchronization correction communication, the synchronization correction communication is repeated a plurality of times at regular intervals. 4. The automatic meter reading system according to claim 2, wherein in one synchronization correction communication, the synchronization correction communication is continuously repeated a plurality of times. 5. The wireless master station according to claim 1, wherein the wireless master station confirms a response from one wireless slave unit at one time of the synchronization correction communication. Automatic meter reading system. 6. The wireless master station according to claim 5, wherein a plurality of the wireless slave stations are assigned to one wireless master station, and the wireless master station sequentially changes the wireless slaves for each synchronization correction communication. An automatic meter reading system that checks the response from the station. 7. The wireless communication device according to claim 1, wherein the wireless communication device performs the next synchronization correction communication when recognizing that the reception of the synchronization correction communication has failed. An automatic meter reading system, wherein the automatic meter reading system shifts to a continuous reception state or a short period intermittent reception state in a time width including a time zone. 8. The wireless communication device according to claim 1, wherein when the wireless slave device confirms that the reception of the synchronization correction communication has failed, the wireless slave device informs the wireless master device of the fact. An automatic meter reading system, wherein the notification is made and the wireless master unit performs the synchronization correction communication again.