JPH11177564A - Communication system to be used for radio meter-reading and radio-meter reading system executing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce unnecessary power consumption at the time of waiting reception by limiting the operation of a radio slave station to be within an irreducibly minimum period. SOLUTION: In a signal recognizing system recognizing line establishment by allowing a radio slave station 2 connected to a meter 1 to recognize an identification signal transmitted by a master station equipment 4 while intermittently operating, a periodical signal characteristic to a system is used and the station 2 detects the periodical signal characteristic to this system to recognize significant communication within its own system or not, and recognizes an individual address signal following the periodical signal characteristic to the system to stepwise recognize a communication request to its own station or not to limit the operation of a circuit within the irreducibly minimum period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system used for a wireless meter reading in which the value of an integrating meter indicating the usage amount of gas, water, electric power and the like is measured using wireless communication. The present invention relates to a wireless meter reading system. The communication method used for the wireless meter reading of the present invention and the wireless meter reading system that implements this method use proprietary intermittent communication technology to reduce the power consumption of the system and allow long-term meter reading without replacing the battery. It has made operation possible.

[0002]

2. Description of the Related Art In the business of meter reading of various meters indicating usage amounts of gas, water, electric power, etc., since the environment where each meter is installed is various, it is easy for a meter reader to visually inspect a visit. There are many cases where it is installed in a non-environment. In order to facilitate the meter reading operation in such a situation where the meter reading is difficult, various trials have been made on the operation and operation of a remote meter reading system using communication means such as a wired telephone line. In addition, utilizing such a remote meter reading system not only enables remedies for meters that are difficult to read, but also improves the efficiency of meter reading and improves the efficiency of meter reading. It has become to.

Further, with the rapid progress of wireless application technology in recent years, the cost of wireless devices and the cost of installation work have become lower than those of wired communication systems. Expectations for the realization of the system are increasing, and various wireless metering systems are starting to be used on a trial basis. In this case, in the wireless meter reading system, in order to make the most of the advantages of the wireless system such as ease of installation and low operating cost, only the built-in battery is used as the power source, and the meter replacement cycle based on the measurement method is used. It is a condition for a practical system that it can be operated without replacing batteries for a certain eight to ten years. However, each currently implemented wireless meter reading system,
In order to satisfy this condition, it is not only necessary to use an expensive large-capacity battery, but also the communication conditions are restricted, and the stage of practical use has not been reached.

[0004]

Generally, in wireless communication, the time required to confirm the connection of a communication line is determined not only by the net required transmission time of the signal itself, but also by the characteristics of the wireless circuit through which the signal passes, that is, the transmission time. It largely depends on the signal response characteristics inherent to the circuit and the receiving circuit, and overcomes the existence of a transient period during which the operation at the start of communication becomes unstable, especially due to the response performance represented by the rise delay time. To do
It is necessary to create communication control software with a sufficient operation delay time.

[0005] Incidentally, in a radio receiving apparatus, the rising delay time until a received signal is output stably is usually 10 ms or more even with good characteristics. Further, in general, when performing data communication, 1200, 1200, etc., in order to receive and recognize control information such as a communication request from a specific partner.
Using a serial code identification signal based on a general signal transmission rate (bit period) such as 2400, 4800, or 9600 bits / sec, a method of recognizing and determining whether a pattern matches a predetermined pattern is performed. Have been done.

When a signal having the above-mentioned general transmission rate (period) is used by such a method, an identification signal (code) is recognized one by one in order to distinguish it from a signal used by another communication system. In order to almost certainly recognize the communication partner by avoiding erroneous determination, at least a synchronization bit string of several tens of bits (usually ten or more bits) for supplementing synchronization and a number of bits as a valid code data component 10 bits
It was necessary to take in a data bit signal sequence (usually more than 10 bits). That is, it is necessary to take in a bit signal sequence of at least about 30 bits in total. By the way, it is possible to communicate with relatively stable line characteristics 2400b
In order to confirm the processing of a 30-bit signal at a signal speed of about ps, a transmission time of 12.5 ms and a receiver start-up time of 3 ms when the wireless circuit used in the present invention is used as it is becomes about 16 ms, Considering some margin (about 20%), it takes about 20 mS.

In some cases, particularly in analog radio communication lines, a method of mutually confirming and recognizing each other by using a tone signal of a specific period is used as an old technique. In order to realize the function of discriminating and detecting the tone signal, a dedicated detection circuit for detecting the tone signal (periodic signal) is required, so that the power consumed by the detection circuit increases. Disadvantages such as increased costs of required circuit components. As mentioned above,
When manufacturing a wireless meter reading system using conventional wireless technology that has been put into practical use, even if the intermittent operation method is adopted, there is a meter reading system that requires communication only several times a month at most. Therefore, the current consumed at the time of transmission does not substantially burden the whole.

[0008] On the other hand, a leakage current constantly flowing through the circuit element when the operation of the wireless metering system is at rest, and a circuit operating current at the time of intermittent reception operation at rest intervals of several seconds to several tens of seconds. Occupies most of the total power consumption. As a result, most of the built-in battery capacity is unnecessarily consumed in a steady and autonomous operation that does not contribute to the actual communication operation at all. . As a result, for example, a large-capacity primary battery of about 10 Ah or more has to be used for power supply of the wireless metering system. In particular, in the field of meter reading for gas, water, electric power, etc., it is required that the stability of the measuring instrument (meter) be maintained for a long period of time, that is, 8 to 10 years without using an external power supply. Have been.

On the other hand, at present, as a standard and easily available battery, for example, a lithium battery having a storage life of 10 years has a standard capacity of about 3 V and 5000 mAh. It is far from realizing a low-cost and easy-to-maintain wireless meter reading system that can be used continuously for a long period of time without replacing a new battery. Due to the situation described above, the conventional wireless metering system uses expensive large-capacity batteries, or provides an excessive pause time to reduce power consumption, on a specific day, and even on a specific time zone. There are many restrictive conditions such that only a communication operation can be performed, and most systems require special operation rules to be defined and used. For this reason, wireless meter reading systems have long been unable to leave practical trial areas, and as a result,
The realization of a wireless meter reading system that can withstand practical use is widely expected.

[0010]

SUMMARY OF THE INVENTION The present invention provides a gas, water,
In a wireless meter reading system that uses a wireless communication to read the value of an integrating meter indicating the amount of power used, etc.,
The wireless slave station connected to the meter uses a periodic signal unique to the system for a signal recognition method in which a line is established by recognizing an identification signal transmitted by the master station device while performing intermittent operation. By detecting a periodic signal unique to the system, it is recognized whether or not significant communication is within the own system, and by recognizing an individual address signal subsequent to the periodic signal unique to the system, a communication request to the own station is recognized. By gradually recognizing whether or not the wireless communication is in progress, the operation of the circuit is limited within the minimum necessary time, and the unnecessary power consumption of the wireless slave station when waiting for reception is greatly reduced. Things.

The wireless meter reading system according to the present invention is composed of hardware consisting of a microprocessor and some peripheral passive circuit elements, and software capable of performing a simple control operation of the hardware. A periodic signal is recognized in a minimum time corresponding to a tone signal period, and a wireless communication line can be established.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a diagram showing the overall configuration of one embodiment of a wireless meter reading system which implements a communication system used for wireless meter reading according to the present invention. In FIG. 1, 1 is a meter and 2 is a meter 1.
Is a slave station device, 3 is a meter reading terminal device carried by the meter reader, and 4 is a master station device mounted on the portable terminal device 3. The slave station device 2 includes a wireless circuit 11, a control circuit 12, a battery 13, a case 14, and an antenna 15,
A specific address (ID) number is set for each meter.

In a meter reading operation by a wireless meter reading system, for example, in a visit meter reading operation, a meter reader approaches a meter in which the meter is to be metered, sets an address (ID) number of the meter in the mobile terminal device 3, and then sets the mobile terminal device. A slave station device 2 connected to a meter having a designated address (ID) number by issuing a communication request from a master station device 4 mounted on the device 3
, And the integrated value of the meter is wirelessly read by the portable terminal device 3. In this case, the reception operation of the slave station device 2 for confirming the communication request signal from the master station device 4 carried by the meter reader has a pause of about 2 seconds in order to reduce the consumption of the battery 13. It is set to perform the operation intermittently.

The master station device 4 is basically connected to the slave station device 2.
However, when making a communication request to the slave station device 2, a periodic signal unique to the system for signal recognition, that is, a unique period that is not generally used, for example, 1400 Hz (0.71 mS ) Is transmitted. The transmission time of the periodic signal peculiar to the system is set so as to be sufficiently longer than the intermittent pause time 2 seconds of the slave station device 2. The wireless circuit 11 of the slave station device 2
A low-power wireless circuit based on narrow-band technology, which can be started at a high speed and can be driven with little current consumption, is used. As an example, the characteristics are as follows: Transmission output 10m
W, transmission rise time about 1 ms, reception rise time about 3 m
S, the current consumption at the time of transmission is about 30 mA, and the current consumption at the time of reception is about 3.5 mA.

The control circuit 12 of the slave station device 2 comprises only a low power consumption microprocessor (MPU) and a few peripheral circuits consuming very little power. The MPU has a characteristic of about 5 mA and a characteristic of about 10 μA at rest. The MPU incorporates software for recognizing a signal received by the wireless circuit 11. As the battery 13 of the slave station device 2, a lithium primary battery which has a storage performance of 10 years and is generally easily available is used. Among lithium primary batteries, among those standardized at the present time, 3 V 5000 mAh
Since this is the largest capacity, the present embodiment aims to enable operation with this capacity.

In the wireless metering system of the present invention having such a configuration, for example, the master station apparatus 4 requests the slave station apparatus 2 of the meter 1 having a specific address (ID) number to transmit the integrated value of the meter 1. Operation for activating communication for communication will be described in detail. In the wireless meter reading system that implements the communication method used for wireless meter reading of the present invention, the slave station device 2 connected to the meter performs intermittent operation while the master station device 4
The line is established by recognizing the identification signal transmitted by the communication device. In the signal recognition method in this case, a periodic signal unique to the system is used. By detecting this system-specific periodic signal, the slave station device 2 recognizes whether the communication is significant within the own system, and recognizes an individual address signal following the system-specific periodic signal. Thus, whether or not the request is a communication request to the own station is made in a stepwise manner.

For this reason, if it is determined that there is no communication request to the own station at each recognition stage, the communication is immediately terminated at that stage, so that the operation of the circuit is limited to a minimum required time. In addition, it is possible to greatly reduce unnecessary power consumption during reception standby. Further, in the slave station device 2, after receiving the periodic signal transmitted by the master station device 4, the frequency signal received by using a confirmation determination method such as a majority decision or a continuous match is a periodic signal unique to the system. It is determined whether there is. Since an odd number of signal period measurements are performed for this determination, it is preferable that the period signal to be used be measured in about 5 or 7 cycles within a range that does not make the signal redundant. The mechanism of the periodic signal detection used in the bright wireless meter reading system of the present invention will be described below with reference to the timing chart of FIG. 2 and the example of the periodic signal of FIGS.

FIG. 2A is a timing chart showing a receiving operation of the slave station device 2, and FIG. 2B is a timing chart showing a transmitting operation of the master station device 4. As shown in FIG. 2A, the slave station device 2 receives the demodulated output signal 2 output from the receiving unit of the wireless circuit 11 in the intermittent reception period 22 via the pause time of 2 seconds.
3, the receiving operation is performed during a fixed period of 10 ms. During the period of the receiving operation for 10 ms, the wireless circuit 11
Is about 3.5 mS, the required signal length is about 5 mS when receiving a periodic signal of about 3.5 mS or about 0.7 mS, and the required signal length is about 5 mS, which is about 10 mS including some margin. Is set to

In order to recognize and determine a predetermined periodic signal by software during this 10 ms, a signal from a partner station must be input at a timing (time slot) at which the receiver performs an intermittent receiving operation. . For this reason, the transmission operation of the master station device 4 which is a legitimate communication partner that starts transmission at least first is, as shown in FIG. 2B, a slave station performing an intermittent reception operation at its own clock timing. When the time is sufficiently longer than the intermittent operation cycle of the device 2, that is, the intermittent reception time is 10 ms and the intermittent pause time is 2S,
It is necessary to transmit a start signal for a period of at least about 2.02S (2S + 0.01S × 2). Note that an ID signal for individual selection is transmitted after the identification signal 21.

In the present invention, in order to save the power consumption of the slave station device 2, the identification signal is recognized in three stages. As a first selection step, the presence or absence of a radio wave transmitted by the master station device is checked. In the second selection step, whether or not the communication is significant within the own system is recognized by detecting a periodic signal unique to the system. Third
In the selection step of (1), by recognizing an individual address signal following the periodic signal unique to the system, it is recognized whether or not the request is a communication request to the own station.

* First selection stage * The slave station device 2 is connected to the radio circuit 1 as shown in FIG.
1 intermittent reception period 22 after a pause of 2 seconds
For a certain period by the reception demodulation output signal 23 output to
If the start (identification) periodic signal 21 transmitted by the master station device 4 cannot be confirmed even if the reception operation is performed within 10 mS, it is determined that there is no communication request to the own station, and 2 seconds are required. Enter pause time. In these intermittent reception operations,
By the first selection step of confirming the presence or absence of radio waves before performing signal recognition determination, when the input of radio waves of a desired frequency cannot be confirmed, the signal recognition operation is not performed, and the state immediately returns to the reception suspended state. Since it is controlled, the power consumption in this case is a small value.

* Second selection stage * Intermittent reception operation As a result of performing the reception operation during 10 ms,
Startup (identification) periodic signal 21 transmitted by master station device 4
Can be confirmed, the process enters a second selection step of measuring the period of the periodic signal 21 for identification. FIG. 3 shows an example of the identification signal 21 used in the wireless metering system of the present invention. Next, in order for the slave station device 2 to efficiently recognize the identification signal transmitted by the master station device 4, the rising or falling edge of the reception signal that changes in an alternating manner in the identification signal 21 shown in FIG. 31 is detected, and T of a cycle time 33 until the next edge 32 is detected is measured.
Is compared with a predetermined cycle time peculiar to the system within an allowable error range to determine whether or not the received signal is a significant signal. In the wireless meter reading system of the present invention, this series of operations is repeated an odd number of times to make a majority decision in order to improve the accuracy of the decision.

In this case, in order to satisfy the set condition of the effective reception time of 5 ms or less, which is intended to be realized by the wireless metering system of the present invention, for example, when a signal of about 1400 Hz is received, about 7 cycles are recognized. Be eligible. Also, as described above, a certain signal length (the number of determination targets: 7)
(7 in the case of the period) can be ensured. In general, the leading portion 34 of the received signal sequence tends to be less reliable than the rear portion 35 due to the transient characteristics of the receiving unit of the radio circuit 11. Can be given different weights to improve the reliability of majority decision.

FIG. 6 shows measurement data for explaining an example in which weighting is determined. In FIG. 6, a measurement result out of the allowable error range of 0: out of the allowable error range is shown. In the weighting determination in FIG. 6, when five signals to be determined are received in the order of 〜, weights (× 2) are added to the rear two signals, and then the determination values for the five signals are added, and OK ≧ This indicates that the determination is made under the condition of No. 3. If the number of determination OKs occupies the majority without weighting, it is recognized as significant communication.

As described above, by adding and comparing the individual judgment results to which weights have been added, analog transmission characteristics different from random errors and the like that are potentially and stochastically generated due to noise interference or the like in a communication system. based on,
Considering the signal rising transient characteristic peculiar to the communication system,
A wireless metering system that has high recognition accuracy and has little useless operation time and that can minimize battery capacity consumption without providing a large reception delay time is realized.

FIG. 4 shows another example of the identification signal 21 used in the wireless metering system of the present invention. The identification signal 21 used in the wireless metering system of the present invention can improve the recognition accuracy by increasing the period to some extent in the analog transient state of the receiver, but basically the entire recognition operation is shortened as much as possible. Figure 4
As shown in the figure, the front part 34 of the identification signal 21 combines a plurality of periodic signals such that the cycle is long (first cycle 41) and the rear part 35 is short (second cycle 42). It is also possible to adopt a method. In this case, the recognition accuracy can be further improved without substantially affecting the entire signal length.

If the frequency is not the frequency of the system as a result of the periodic signal check for identification, it is determined that the request is not a communication request to the own station, and the communication is terminated to enter a communication pause state. Not done. Since the consumption of power used for the identification periodic signal check is less than the power consumed when performing the individual slave station ID identification operation, a plurality of identification periodic signals are set, By grouping the slave stations for each identification periodic signal, it is possible to narrow down the selection of slave stations in the second selection stage of checking the identification periodic signal. Thus, the second selection stage is provided, so that the power consumption of the individual slave station is greatly reduced.

* Third Selection Step * When the identification signal is recognized as a significant communication request as a result of the above-described series of operations, the slave station device 2 performs the third selection step. The operation for identifying an individual slave station ID is started. Third
The operation at the selection stage is described with reference to the time chart of FIG.

FIG. 5 is a time chart showing details of the operation of the master station device and the slave station device in the operation of the third selection stage of the embodiment of the wireless metering system of the present invention. 5A shows the configuration of a start signal transmitted by the master station device, FIG. 5B shows the timing of intermittent reception of the slave station device, and FIG. 5C shows the signal of the slave station device. It shows an example of recognition determination operation. As a result of the discrimination of the identification signal, when it is confirmed that the identification signal is a significant communication request, the slave station device 2 performs the operation of identifying the individual slave station ID. The identification data of the individual slave station ID in the data part of the identification signal transmitted from the station device 4 is received. For example, slave station device 2 and master station device 4
In FIG. 5 showing the signal timing of the slave station device 2,
When it recognizes a radio wave of a required frequency from the master station device 4 at the # 1 intermittent reception timing 51, it enters an identification reception operation 52, and when a desired periodic signal is recognized under required conditions, it generates a significant signal. Judgment is made, and the standby operation 53 and the reception operation 54 of each slave station ID data are performed, and after a predetermined procedure, the operation of the mutual communication 55 is started.

The slave station that has completed its own communication enters the communication pause state again, and does not perform the intermittent reception operation within a certain time during which there is a possibility that the peripheral slave stations will perform communication, and enters a complete sleep state. . Further, as a result of receiving the identification ID and checking the identification data, if the identification data is not the ID of the slave station device 2, it is determined that the request is not a communication request to the own station, and the communication is aborted and the communication is suspended to enter an intermittent standby operation state. In addition, when the slave station device 2 cannot recognize the radio wave of the master station device 4 and when the slave station device 2 cannot recognize (identify) a significant signal even if the slave station device 2 receives the radio wave of the master station device 4 It immediately enters the intermittent standby operation state.

The most important points of the operation of the slave station device 2 in the series of flows described above are shown in the flowchart of FIG. FIG. 7 is a flowchart of software used in the slave station device 2 of the wireless metering system according to the present invention, and illustrates the operation of the slave station device 2 from step 101 of setting the intermittent timer to step 115 of disconnecting the line. It is controlling. The internal timer monitoring conditions such as the reception pause time 22 and the intermittent reception period 23 are set (step 101), the pause timer value is monitored (step 102), and the presence / absence of time-up is confirmed (step 103). Do.

As a result, if the set conditions are not satisfied, the process returns to the timer monitor 102. If the time is up, the receiving circuit is turned on (step 104), and the presence or absence of a carrier (desired radio wave) is checked (step 105). And BU
In the SY level determination condition (step 106), B
If the USY condition is not satisfied, the process returns to the timer setting 101, and if it is regarded as BUSY, a confirmation measurement of a periodic signal transmitted by the master station is performed (step 107). Next, when a periodic signal cannot be confirmed at all, and the confirmed signal period is determined based on a predetermined condition (step 10).
Perform 8). As a result, if they do not match the predetermined cycle, the process returns to the intermittent timer setting 101, and if they do match, the majority decision (snub 110) is performed via the next majority process (step 109).

If the result of the majority decision (step 110) is negative, the process returns to the intermittent timer setting 101. If the result of the majority decision (step 110) is affirmative, a standby check is performed for the polling start ID number and end point ID number of the individual ID (step 111). As a result of confirming the ID number (step 111), if the own station ID is not included, the process returns to the intermittent timer setting 101. If the ID is included, the polling access from the master station device 4 is waited.
Each slave station device 2 sequentially transmits response signals in the order of access (step 113), and performs mutual communication for meter reading data collection (step 114). The slave station device 2 that has completed the series of communication processing up to now disconnects the wireless communication line (step 11).
5) Then return to the start. In actual operation,
If it is not necessary to access again shortly after the meter reading communication operation is completed normally, set an intermittent timer to provide a forced pause time so that unnecessary reception confirmation is not performed when reading meters in other nearby areas. The pause timer set value for the first restart in 101 may be a large value such as one hour, for example.

As described above, according to the present invention, in a wireless meter reading system in which a wireless slave station recognizes an identification signal transmitted from a master station device while performing intermittent operation, a line is established, and system recognition is unique to signal recognition. By using a periodic signal of the following, as a first selection stage of signal recognition:
The presence or absence of a radio wave transmitted by the master station apparatus is checked, and as a second selection step, a periodic signal unique to the system is detected to recognize whether or not significant communication is within the own system. As a selection step, by recognizing an individual address signal following a system-specific periodic signal, recognition of a communication request to the own station is performed stepwise. For this reason, the operation time of the circuit of the wireless slave station is limited to a necessary minimum, and unnecessary power consumption during standby for reception can be greatly reduced.

[0035]

As is apparent from the above description, the wireless metering system of the present invention, which implements the communication system used for wireless meter reading, uses a wireless meter for indicating the amount of gas, water, electric power, etc. used. In a wireless remote meter reading system that performs meter reading using communication, a system-specific periodic signal is used for a signal recognition method for establishing a line, and a wireless slave station detects the system-specific periodic signal, By recognizing whether or not the communication is significant within the own system and recognizing an individual address signal following the periodic signal unique to the system, recognition of whether or not the communication request is for the own station is performed step by step. By doing so, the operation of the wireless slave station can be limited within the minimum time required, so that unnecessary power consumption during reception standby can be significantly reduced.

For this reason, by using the wireless meter reading system of the present invention for a specific meter, which has conventionally been difficult to read, the meter reading operation of the specific meter can be easily performed, and in a snowfall area, it is easy to read in the winter. Most of the regional distress problems, such as the inability to read the meter itself during the period and the inability to obtain accurate monthly meter values, can be solved. At the same time, various status information of the meter device can be easily collected, and the public benefit that the utility business originally aims for can be provided as a new additional information service. And a wide range of effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of a wireless meter reading system that implements a communication method used for wireless meter reading according to the present invention.

FIG. 2 is a timing chart for explaining a mechanism of periodic signal detection used in the bright wireless metering system of the present invention.

FIG. 3 is a diagram illustrating an example of a periodic signal used in a wireless meter reading system that implements a communication method used for wireless meter reading according to the present invention.

FIG. 4 is a diagram illustrating an example of a periodic signal used in a wireless meter reading system that implements a communication method used for wireless meter reading according to the present invention.

FIG. 5 is a time chart showing details of the operation of the master station device and the slave station device in the operation of the third selection stage of the embodiment of the wireless metering system of the present invention.

FIG. 6 shows measurement data for explaining a case in which weighting is determined.

FIG. 7 shows a flowchart of software used in the slave station device 2 of the wireless metering system of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Meter 2 ... Slave station device 3 ... Meter reading terminal device 4 ... Master station device 11 ... Wireless circuit 12 ... Control circuit 13 ... Battery 14 ... Case 15 ... Antenna 21 ... Identification periodic signal 22 ... Intermittent reception period 23 ... Reception demodulation signal 24 ... Individual selection ID signal 31 ... Rising edge of identification periodic signal 32 ... The next rising edge of the periodic signal for identification 33... The period of the signal for identification 34... The front part of the signal for identification 35... The rear part of the signal for identification 41. First cycle of signal 42... Second cycle of identification signal by combination of different cycles 51... Intermittent standby period 52... Identification operation 53... Data standby operation 54. Receiving operation 55 ... Mutual communication operation

Claims (10)

[Claims] 1. A wireless communication station connected to a meter performs intermittent operation to measure the value of the meter indicating the usage of gas, water, electric power, etc. using wireless communication. In a wireless meter reading system that establishes a line by recognizing an identification signal to be transmitted, a periodic signal unique to the system is used for signal recognition, and the wireless slave station detects the periodic signal unique to the system, thereby automatically detecting the signal. By recognizing significant communication within the system and recognizing individual address signals following the periodic signal unique to the system, recognition of whether or not a communication request to the own station is performed step by step. Communication method used for wireless meter reading. 2. A wireless slave station connected to the meter performs an intermittent operation to read a meter value indicating a usage amount of gas, water, electric power or the like using wireless communication. In a wireless meter reading system in which a line is established by recognizing an identification signal to be transmitted, a periodic signal unique to the system is used for signal recognition. Is confirmed, and as a second selection step, a periodic signal unique to the system is detected to recognize whether or not significant communication is within the own system. Further, as a third selection step, a system-specific unique signal is recognized. By recognizing the individual address signal following the periodic signal, and by recognizing whether the request is a communication request for the own station in a stepwise manner, the operation of the circuit of the wireless slave station can be performed within the minimum necessary time. Limited , Communication method using the wireless meter reading which is adapted to reduce unnecessary power consumption during reception standby. 3. A communication system used for wireless meter reading according to claim 1, wherein the periodic signal unique to the system is a unique and fixed single-period signal which is not generally used. . 4. A communication system for use in wireless meter reading according to claim 1, wherein the periodic signal unique to the system is a combination of two or more types of periodic signals. 5. A system according to claim 1, wherein the recognition accuracy of the significant signal is improved by adding a weight to each signal determination result in the signal sequence of the periodic signal unique to the system. Communication method used for wireless meter reading. 6. A plurality of wireless slave stations each having an individual address for transmitting a meter value indicating the usage amount of gas, water, electric power or the like using wireless communication, and wirelessly specifying an individual address. In a wireless meter reading system, which calls a slave station and receives a value of a meter connected to a wireless slave station by using wireless communication, a wireless meter reading system comprising: The wireless slave station has a calling means for transmitting an address signal for each wireless slave station after transmitting a periodic signal for a certain period of time. A wireless metering system comprising a line establishing means for establishing a line by recognizing a periodic signal unique to the system. 7. A plurality of wireless slave stations each having an individual address for transmitting a meter value indicating a usage amount of gas, water, electric power, or the like using wireless communication, and wirelessly specifying an individual address. Call the slave station and read the value of the connected meter of the wireless slave station,
In a wireless meter reading system including a wireless master station device that receives by using wireless communication, a master station device transmits a periodic signal unique to a system for a certain period of time after calling a wireless slave station, and then individually addresses the wireless slave station. A wireless slave station for transmitting a signal, the wireless slave station confirms, as a first selection step, the presence or absence of radio waves transmitted by the master station apparatus, and as a second selection step, a periodic signal unique to the system. To determine whether the communication is significant within the own system, and as a third selection step, by recognizing an individual address signal following the periodic signal unique to the system, A wireless metering system comprising a line establishing means for establishing a line by performing a step-by-step identification of whether or not the request is a communication request. 8. The wireless metering system according to claim 6, wherein the periodic signal unique to the system is a unique and fixed single-period signal that is not generally used. 9. The wireless metering system according to claim 6, wherein the periodic signal unique to the system is a combination of two or more types of periodic signals. 10. A system according to claim 6, wherein the recognition accuracy of the significant signal is improved by adding a weight to each signal determination result in the signal sequence of the periodic signal unique to the system. Wireless meter reading system.