JP2010141690A - Radio transmitter and receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contribute in specifying the cause of a communicative fault, by storing the decision result of the periodical measurement of characteristics of an antenna, in a radio transmitter and receiver that include by a wireless communication system for collecting information containing measured values of a metering device by radio communication. <P>SOLUTION: The radio transmitter and receiver collect information containing measured the values of a metering device by radio communication. A slave unit 2, which is a radio transmitter and receiver measures characteristics of the antenna 21 at a measuring interval stored beforehand by a timing control means 24, for example, by a lapse of each one hour, and measures, for example, the impedance by an antenna-measuring means 25 so as to store the measured result to a memory means 26. Furthermore, when the determined value of the measured result of the antenna 21 goes out of range which has been defined beforehand, the time is also stored, and additionally, this is notified to a master unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wireless transmission / reception device, and more particularly to a wireless transmission / reception device provided in a wireless metering system for remotely reading a gas meter or a water meter by wireless communication.

For measuring instruments such as gas meters and water meters, for example, meter readers read the indicator values of meters installed in each house or facility every month or every two months, and meter readings such as handheld terminals (HT) that are carried around A meter reading operation for inputting the read meter reading value to the terminal is performed.
In such meter reading work, for example, it is difficult for meter readers to read the meter due to factors such as the presence of objects near the meter, the presence of dogs, the meter in the building, or the meter being buried due to snow. There are cases. Furthermore, in the case of a water meter, the meter reading may be dangerous because the meter is installed in a place where the meter pointer cannot be visually recognized unless the heavy iron lid is opened.

  For such problems, a wireless metering system is used to remotely measure the slave unit by connecting the slave unit to a measuring instrument such as a gas meter or water meter using a master unit and slave unit that are wireless transceivers. Has been. In such a wireless meter reading system, by operating the master unit from a location away from the meter, information such as the indicator value of the meter can be collected by the master unit via the slave unit connected to the meter.

  In addition, a master unit is installed at the eaves of each household so that the meter reader does not have to go to each house or facility, or a master unit is installed on the wall of the common floor in apartment buildings such as apartments. There is also a form of an automatic meter reading system in which central meter reading is performed from a meter reading center or the like by connecting the master unit to a public line.

  In such a wireless meter reading system, a specific low-power radio station for telemeter tele-control in the 430 MHz band is often used, but the transmittable output is relatively small at 10 mW or less. And since radio waves have such characteristics as attenuation, reflection, and diffraction due to obstacles such as buildings, the radio waves received by the main unit and slave units depend on the positional relationship between the obstacles and the master unit and slave units. , May weaken.

  In addition, the parent device and the child device have antennas for emitting and receiving radio waves, but the antennas have impedance and VSWR (Voltage Standing Wave Ratio: voltage constant) depending on the surrounding environment, especially the proximity of metals. The standing wave ratio) value and the reflection coefficient change. This is because the antenna transmission / reception performance changes, and in many cases, the performance deteriorates.

  Some conventional systems measure the strength of radio waves at the time of reception by the master unit or slave unit, that is, the electric field strength, periodically or when necessary, and confirm whether the electric field strength level can be satisfactorily communicated. . In addition, there are those that perform transmission output and antenna impedance matching from the measurement result of the electric field strength.

For example, in Patent Document 1, in a wireless data communication system that performs wireless communication between two facility devices that are installed apart from each other, information such as communication errors in each facility device can be grasped and the cause can be investigated. A technology intended to ensure the long-term reliability of the system is disclosed. In this system, one of the two equipments includes a field strength measuring means for measuring a field strength value when a signal transmitted from the other equipment is received, and the field strength measuring means. Electric field strength determination means for determining whether or not the measured electric field strength value has reached a predetermined threshold level, and at least one of the electric field strength value of the electric field strength measurement means and the information determined by the electric field strength determination means And information reporting means for reporting to the outside. Here, when the measured electric field intensity of the received radio wave does not reach the threshold level, notification is made or impedance matching of the antenna is performed.
Japanese Patent Laid-Open No. 10-172087

  However, in the conventional system disclosed in Patent Document 1, it is possible to know that the strength of the radio wave received by the parent device or the child device has changed, but the cause, for example, a structure such as a new building in the vicinity. Whether the communication environment has changed due to the installation of an obstacle or an obstacle placed, the strength of the radio wave has changed, or the performance of the antenna has changed due to a metal obstacle placed near the antenna, etc. Cannot be specified.

  The present invention has been made in view of the above circumstances, and in a wireless transmission / reception apparatus provided in a wireless communication system that collects information including measurement values of a measuring instrument by wireless communication, antenna characteristics are measured at predetermined time intervals. Thus, an object of the present invention is to provide a wireless transmission / reception apparatus that can contribute to the identification of the cause of a communication failure by storing the measurement result.

  The invention according to claim 1 is a wireless transmission / reception apparatus provided in a wireless communication system that collects information including a measurement value of a measuring instrument by wireless communication, wherein the wireless transmission / reception apparatus includes wireless communication means, an antenna used for wireless communication, An antenna measuring means for measuring the characteristics of the antenna, a time measuring means, and a storage means are provided. The antenna measuring means measures the antenna characteristics at a predetermined interval, and the measurement result is stored in the storage means. A wireless transmission / reception device characterized by the above.

  According to a second aspect of the present invention, in the first aspect of the present invention, a determination value is set in the storage unit in advance. The measurement result of the measured antenna characteristic is compared with the determination value, and the antenna characteristic is determined from the comparison result. When it is determined that the condition has deteriorated, the measurement result is stored in the storage device in the previous period.

  The invention of claim 3 is the invention of claim 1 or 2, wherein the time measuring means has a function of generating current time information, and the measurement result is stored in the storage means together with the current time information. It is a thing.

  The invention of claim 4 is the invention of claim 1 or 2, wherein the wireless transmission / reception device is connected to a measuring instrument, collects current time information from the measuring instrument, and displays the measurement result together with the current time information. The information is stored in the storage means.

  According to a fifth aspect of the present invention, in the first or second aspect of the invention, the wireless transmission / reception device is connected to a center device via a network, collects current time information from the center device, and together with the current measurement result In both cases, the measurement result is stored in the storage means.

  The invention of claim 6 is characterized in that, in the invention of claim 2, when the wireless transmission / reception apparatus determines that the antenna characteristic has deteriorated, the wireless communication means notifies the outside.

  A seventh aspect of the invention is characterized in that, in any one of the first to sixth aspects of the invention, the antenna characteristic is any one or a combination of impedance, VSWR value, reflection coefficient.

  According to the present invention, a wireless transmission / reception apparatus such as a master unit or a slave unit has an antenna characteristic measuring unit, a time measuring unit, and a storage unit, and measures the antenna characteristic at a preset time interval and stores it in the storage unit. This makes it possible to know changes in antenna performance, etc., and is useful for identifying the cause of communication problems.

In addition, since the determination value of the antenna characteristic is stored in the storage means in advance, the measurement result is compared with the determination value at the time of periodic antenna characteristic measurement, and the quality of the antenna state is stored. It is easy to understand that the antenna characteristics have deteriorated, and even those who do not have special knowledge about antennas and radio can know whether the antenna performance is good or bad.
In addition, since the measurement time is stored together with the measurement result of the antenna characteristics, when the abnormality occurs, the date and time of occurrence is known, which is useful for identifying the cause of the abnormality.

Further, since the time information is collected from the measuring instrument or the center device, it is not necessary to provide the calendar function to the wireless transmission / reception device, so that time and labor for setting the date and time are not required, and malfunction due to a setting error can be prevented.
In addition, when it is determined that the antenna characteristics have deteriorated, the notification is made to the outside, so that the occurrence of an abnormality can be confirmed at an early stage, and the treatment can be performed quickly.
Further, the antenna characteristic value measured in the parent device or the child device is any one or more of the impedance VSWR value of the antenna, the reflection coefficient of the antenna, and it is possible to accurately grasp the performance of the antenna.

Embodiments of a wireless meter reading system according to the present invention will be specifically described below with reference to the accompanying drawings.
FIG. 1 is a diagram for explaining a configuration example of a wireless meter reading system according to the present invention. In FIG. 1, 1 is a master unit of the wireless meter reading system, and 2 is a slave unit of the wireless meter reading system. Equivalent to. Reference numeral 3 denotes a measuring instrument (meter) which is an object of meter reading. The wireless meter reading system of this example is composed of a master unit 1 that collects information such as a meter reading value of the measuring instrument 3 and a slave unit 2 connected to the meter 3, and between the master unit 1 and the slave unit 2 Wireless communication with each other, and data of the measuring device 3 and the slave device 2 are collected by the master device 1.

  FIG. 2 is a diagram for explaining another configuration example of the wireless meter reading system according to the present invention, in which 4 is an external device. In the wireless meter reading system of this example, the master unit 1 is connected to the external device 4. As the external device 4, for example, a handy terminal, a centralized meter reading board, a display, a terminal network control device, or the like can be applied.

FIG. 3 is a diagram showing a configuration example of a slave unit that is a wireless transmission / reception apparatus applicable to the wireless meter reading system of the present invention.
The subunit | mobile_unit 2 of a radio | wireless transmission / reception apparatus has the radio | wireless communication means 22 for performing radio | wireless communication, the antenna 21, the antenna measurement means 25 which measures the characteristic of the antenna 21, and the time measuring means which produces | generates time, such as a measurement interval. 24, storage means 26 for storing the measurement results and determination values to be described later, and control means 23 for controlling these means and communicating with the connected measuring instrument 3. . The antenna measuring means 25 is an impedance measuring circuit for measuring the impedance of the antenna 21, a measuring circuit for the VSWR (voltage standing wave ratio) value of the antenna 21, a measuring circuit for the reflection coefficient, Or it is comprised from the circuit which combined those two or more.

FIG. 4 is a diagram showing a configuration example of a master unit that is a wireless transmission / reception apparatus applicable to the wireless meter reading system of the present invention.
The base unit 1 of the wireless transmission / reception apparatus includes a wireless communication unit 12 for performing wireless communication, an antenna 11, an antenna measuring unit 15 for measuring characteristics of the antenna 11, and a time measuring unit for generating time such as an interval for performing the measurement. 14, a storage unit 16 that stores measurement results, a determination value that will be described later, and the like, and a control unit 13 that controls each unit and communicates with the connected external device 4. The antenna measurement means 15 is an impedance measurement circuit that measures the impedance of the antenna 11, a measurement circuit for the VSWR (voltage standing wave ratio) value of the antenna 11, a measurement circuit for the reflection coefficient, Or it is comprised from the circuit which combined those two or more.

The operation of one embodiment of the system shown in FIG. 1 using the slave shown in FIG. 3 will be described below.
The storage means 26 of the handset 2 of FIG. 3 stores in advance measurement interval information for performing antenna measurement, for example, 1 hour.
The control means 23 measures the measurement interval by the time measurement means 24, and measures the impedance of the antenna 21 by the impedance measurement circuit as the antenna measurement means 25 every time the measurement interval elapses and stores the measurement result. The data are sequentially accumulated in the means 26.

  Here, since the storage capacity of the storage means 26 is limited, when the capacity is exceeded, the oldest data is erased and the latest data is saved instead, so that the latest data is always updated. Yes. When the free capacity of the storage means 26 decreases, the measurement interval may be lengthened, or the date and time for starting storage may be set. Further, when the storage capacity of the storage means 26 is full, subsequent storage may not be performed.

Then, the user can connect the slave unit 2 by wireless communication from the master unit 1 or another wireless device, or by connecting a reading device to the input / output unit (not shown) of the slave unit 2 or the input / output unit of the measuring instrument 3 and by wired communication. By reading out the antenna characteristic data stored in the storage means 26 and displaying and analyzing it, it becomes possible to confirm the change in the electromagnetic environment around the handset 2.
In this embodiment, the antenna measurement means 25 is an impedance measurement circuit for measuring the impedance of the antenna 21. However, the antenna measurement means 25 is a measurement circuit for the VSWR value of the antenna 21, a measurement circuit for the reflection coefficient, or the like. The combinational circuit may be used.

The operation of another embodiment of the system shown in FIG. 1 using the slave shown in FIG. 3 will be described below.
In this embodiment, in the slave shown in FIG. 3, the impedance of the antenna is measured at a preset interval as in the previous embodiment. The time measuring means 24 has a calendar function and can generate the current date and time, that is, current time information.
In addition, the storage means 26 of the slave unit 2 has, as an example of the determination value, 50Ω ± 10%, that is, a determination value (here, an allowable range) for determining that the antenna is good between 45Ω and 55Ω and the other is antenna deterioration. Stored in advance. Here, the determination value is an example, and is not limited to this value.

  Then, the control unit 23 compares the measurement result obtained by the antenna measurement unit 25 with the determination value stored in the storage unit 26, and determines that the antenna characteristics are good if the measurement result is within a range of 50Ω ± 10%. To do. If it is determined that the antenna characteristics are good, it is not essential to store the measurement results in the storage means 26. However, if the measurement results are outside the range of 50Ω ± 10%, the antenna characteristics deteriorate. And the measurement result by the antenna measurement means 25 is stored in the storage means 26 together with the current time information (year / month / day and hour / minute) as abnormality information.

  Then, the user can connect the slave unit 2 by wireless communication from the master unit 1 or another wireless device, or by connecting a reading device to the input / output unit (not shown) of the slave unit 2 or the input / output unit of the measuring instrument 3 and by wired communication. By reading out the measurement result and the date and time of occurrence of the abnormality stored in the storage means 26, it is possible to confirm the change in the electromagnetic environment around the slave unit 2.

In this embodiment, the time measuring means 24 has a calendar function, but even a simple timer that measures the elapsed time since manufacture or installation can identify the date and time of occurrence of an abnormality in combination with other information. Any means can be used.
Further, the calendar of the time measuring means 24 may be corrected by communicating with the measuring instrument 3 that is regularly connected such as once a month and obtaining the current time information from the measuring instrument 3. . Furthermore, instead of periodic communication, information on the current date and time may be read from the measuring instrument 3 together with the meter reading value at a communication opportunity when the meter 3 is read.

When the VSWR value is measured as the antenna characteristic, the determination value of the VSWR value is 3 as an example of the determination value. Since the VSWR value does not take a value less than 1.0, it is determined that the VSWR value is between 1 and 3 is good, and the case where it is 3 or more is antenna deterioration.
When the reflection coefficient is used as the antenna characteristic, the reflection coefficient determination value is set to 0.5, 0 to 0.5 is determined to be good antenna, and 0.5 to 1.0 is determined to be antenna deterioration.

The operation of the embodiment of the system of FIG. 2 using the slave unit of FIG. 3 and the master unit of FIG. 4 will be described below.
In the system configuration of FIG. 2, the external device 4 is a terminal network control device, and the external device 4 is connected to a center device via a network (not shown).
In FIG. 2, the master device 1 and the external device 4 are shown as being connected by wire, but the function of the external device 4 may be integrated into the master device 1, and its form It is not something to be caught in.

In the slave unit shown in FIG. 3, the storage means 26 stores measurement interval information, for example, 1 hour as an example, 50Ω ± 10% as an example of a judgment value, that is, between 45Ω and 55Ω, the antenna is good, and the others are antenna deterioration. Determination values for determination are stored in advance.
The control means 23 measures the measurement interval by the time measurement means 24, and measures the impedance of the antenna 21 by the impedance measurement circuit which is the antenna measurement means 25 every time the measurement interval elapses. The determination value stored in the storage means 26 is compared, and if the measurement result is out of the range of 50Ω ± 10%, it is determined that the antenna characteristic is deteriorated, and the measurement result is stored together with the current time information as abnormality information. Store in means 26.

Further, the control unit 23 calls the external base unit 1 by the wireless communication unit 22 and transmits the occurrence of the abnormality of the antenna 21 by wireless communication. The control unit 13 of the base unit 1 operates to prepare for a call from the slave unit 2 by the wireless communication unit 12 and receives a call from the slave unit 2 and a communication in which an abnormality occurs in the antenna 21 of the slave unit 2 Then, it communicates with the external device 4 and operates to notify the external center device that an abnormality has occurred in the handset 2.
Here, depending on the degree of abnormality of the antenna characteristics of the slave unit 2, there is a possibility that communication with the master unit 1 may be disabled. Therefore, an antenna degradation determination value is set in a separately communicable area, and communication is disabled. Before the event, the slave unit 1 notifies the master unit 2 that an abnormality in the antenna characteristics has occurred, or the slave unit 2 is provided with a display means such as an LED to emit light in the event of an abnormality and notify the outside. do it.

  In addition, when it is determined that the antenna characteristic is abnormal in the slave unit 2, it is conceivable that abnormalities are continuously detected. However, if the base unit 1 is notified each time it is detected, power is consumed wastefully, Since the wireless communication may be disturbed, the control unit 23 of the slave unit 2 continuously detects abnormalities in the antenna characteristics until it detects normality a predetermined number of times, for example, three consecutive times. In consideration of the case where the report to the master unit 1 is stopped or the center device cannot receive the report from the master unit 1 for some reason, the report is made once every fixed time, for example every six hours. I am doing so.

In addition to the above operation, the base unit 1 performs the following operation.
In the storage means 16, measurement interval information, for example, 1 hour as an example, 50Ω ± 10% as an example of a determination value, that is, a determination value for determining that the antenna is good between 45Ω and 55Ω and the other is antenna deterioration in advance. It is remembered.

  The control means 13 measures the measurement interval by the time measurement means 14, and measures the impedance of the antenna 11 by the impedance measurement circuit which is the antenna measurement means 15 every time the measurement interval elapses. The determination value stored in the storage means 16 is compared. If the measurement result is out of the range of 50Ω ± 10%, it is determined that the antenna characteristic is deteriorated and the measurement result is stored together with the current time information as abnormality information. The information is stored in the means 16 and an abnormality is notified to a center device (not shown) via the external connection device 4.

In addition, the operation when the abnormality is continuously detected is the same operation as that of the slave unit 2. The antenna measurement means 15 in the base unit 1 is an impedance measurement circuit that measures the impedance of the antenna 11, but, like the antenna measurement means 25 in the handset 2, is a measurement circuit for the VSWR value of the antenna 11, It may be a reflection coefficient measurement circuit or a combination of the circuits.
The base unit 1 may collect current time information from a center device connected via the external device 4.

It is a figure for demonstrating the structural example of the wireless meter-reading system by this invention. It is a figure for demonstrating the other structural example of the wireless meter-reading system by this invention. It is a figure which shows the structural example of the subunit | mobile_unit of the radio | wireless transmission / reception apparatus applicable to the radio | wireless meter-reading system of this invention. It is a figure which shows the structural example of the main | base station of the radio | wireless transmitter / receiver applicable to the radio | wireless meter-reading system of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Master machine, 2 ... Slave machine, 3 ... Measuring instrument, 4 ... External device, 11, 21 ... Antenna, 12, 22 ... Wireless communication means, 13, 23 ... Control means, 14, 24 ... Time measuring means, 15, 25 ... Antenna measuring means, 16, 26 ... Storage means.

Claims (7)

  In a wireless transmission / reception apparatus provided in a wireless communication system that collects information including a measurement value of a measuring instrument by wireless communication, the wireless transmission / reception apparatus measures wireless communication means, an antenna used for wireless communication, and characteristics of the antenna. A radio transmission / reception apparatus comprising an antenna measurement unit, a timing unit, and a storage unit, wherein the antenna measurement unit measures antenna characteristics at a predetermined interval and stores the measurement result in the storage unit .   A determination value is set in advance in the storage means, and the measurement result of the measured antenna characteristic is compared with the determination value. When it is determined from the comparison result that the antenna characteristic has deteriorated, the measurement result is stored in the previous period. The wireless transmission / reception apparatus according to claim 1, wherein the wireless transmission / reception apparatus is stored in the apparatus.   The radio transmission / reception apparatus according to claim 1, wherein the time measuring unit has a function of generating current time information, and stores the measurement result together with the current time information in the storage unit.   3. The wireless transmitter / receiver is connected to a measuring instrument, collects current time information from the measuring instrument, and stores the measurement result together with the current time information in the storage means. The wireless transmission / reception apparatus described.   The wireless transmission / reception device is connected to a center device via a network, collects current time information from the center device, and stores the measurement result together with the current measurement result in the storage means. The wireless transmission / reception apparatus according to claim 1.   The wireless transmission / reception apparatus according to claim 2, wherein when the wireless transmission / reception apparatus determines that the antenna characteristic has deteriorated, the wireless communication means notifies the wireless transmission / reception apparatus to the outside.   The wireless transmission / reception apparatus according to claim 1, wherein the antenna characteristic is any one or a combination of an impedance, a VSWR value, and a reflection coefficient.