JP6281337B2 - Communication device, meter reading system provided with communication device, and drive signal detection method in communication device - Google Patents

Description

  The present invention relates to a communication device, a meter reading system including the communication device, and a drive signal detection method in the communication device.

A system that connects the meter reading device of a meter meter and a wireless slave unit to transmit the meter reading device unattended, and the wireless slave unit transmits the “meter meter reading value” and “meter meter alarm” acquired from the meter meter to the center (Meter reading system) is known (see Patent Document 1).
FIG. 8 is a diagram schematically illustrating an example of a conventional meter reading system.
The meter reading system includes a meter reading meter (for example, a gas meter reading meter) 1, a wireless slave device 2, a wireless master device 3, and a meter reading center (center) 4.
In this meter-reading system, the meter-reading meter reading value and the meter-reading meter alarm from the meter-reading meter 1 are received by the wireless slave unit 2 connected to the meter-reading meter 1, and the wireless master unit 3 is further wirelessly communicated from the wireless slave unit 2 by wireless communication. The data is transmitted from the base unit 3 to the center 4 through a public communication line (not shown). Further, from the center 4, a meter reading request or the like is transmitted to the meter reading meter 1 through a reverse route.

By the way, in order to perform communication as described above in such a meter reading system, it is necessary to make communication settings so that the meter meter 1 and the wireless slave unit 2 can communicate with each other.
FIG. 9 is a diagram schematically showing a procedure for communication setting performed between the meter-reading meter and the wireless slave unit.
As shown in FIG. 9, in general, the communication setting between the meter-reading meter and the wireless slave is first transmitted from the meter-reading meter 1 as a start signal, and the wireless slave 2 receives and detects it. It starts with that. That is, the meter reading meter 1 transmits a start request signal to the wireless slave unit 2 for a certain period of time to transmit a communication start request. The wireless handset 2 that has received the start request signal transmits a data transmission request to the meter-reading meter 1 when detecting this next as a start request signal. When the meter-reading meter 1 receives a data transmission request from the wireless slave unit 2, the meter-reading meter 1 makes a data transmission response to the wireless slave unit 2. Thereby, the communication setting between a meter-reading meter and a wireless cordless handset is established.

In the above-described procedure, when the wireless slave device 2 receives the activation request signal from the meter-reading meter 1, the wireless slave device 2 detects the activation request signal in the following procedure.
That is, first, the “activation request signal” transmitted from the meter-reading meter 1 is usually a standardized signal width (standard signal width) as the signal width (time width) of the activation request signal.
Next, the standard time width “Ams (milliseconds)” is used as the detection width of the activation request signal, and the error “Bms” is added thereto, and the time of the signal width (time width) “A” ms ± “B” ms. A width (here, a prescribed value or a signal width detectable region) is set.
Next, the wireless handset 2 detects a reception signal (start-up request signal) within this specified value as a start-up request signal. On the other hand, if it is not within the specified value of the “start-up request signal”, The activation request signal received without detection is discarded.

FIG. 10 illustrates the above description, and is a diagram for explaining the relationship between the signal width of the activation request signal transmitted from the meter-reading meter 1 and whether or not the wireless slave unit 2 can detect.
That is, when the activation request signals X, Y, and Z are transmitted from the meter-reading meter 1, the signal width of the activation request signal X does not reach the standard signal width-error signal width detectable region, and the activation request signal Since the signal width of Z exceeds the standard signal width + error signal width detectable region, both are discarded on the wireless slave device 2 side as detection failure. Only the activation request signal Y has a signal width within the standard signal width ± error region, and is detected as the activation request signal.

By the way, even if the signal width of the activation request signal transmitted from the meter-reading meter 1 is set to the standard signal width, the activation request signal actually received has a signal width distributed around the standard signal width. Therefore, as described above, a signal width obtained by adding an error to the standard signal width is set so that the activation request signal can be detected with a probability that there is no practical problem.
However, in addition to this, since the signal width of the activation request signal changes due to the surrounding communication environment or aging, etc., when the deviation from the standard width of the signal width of the activation request signal actually received increases, Activation request signals that deviate from the error range of the activation request signal increase. Therefore, as it is, even if a start request signal is transmitted from the meter-reading meter 1 and the wireless slave unit 2 receives it, there is a possibility that it will not be detected and discarded as it is. That is, the case where the wireless slave device 2 misses the activation request signal increases, and in this case, there is a problem that the case where communication setting between the meter-reading meter 1 and the wireless slave device 2 cannot be performed increases.

JP 2007-10409 A

  The present invention has been made to solve the above-described problems between communication devices, for example, the conventional meter-reading meter and the wireless slave device, and its purpose is to communicate the communication width (time) of an activation request signal from another communication device. (Width) changes over time from the set value, the activation request signal detection width is automatically tracked and changed according to the peak value of the communication width accordingly, so that the activation request signal in the receiving side communication device is missed. Is to prevent.

  The present invention detects the signal width of the activation request signal when the activation request signal of another communication device is received, and the activation request only when the detected signal width is within a preset signal width detectable region. A communication device capable of detecting a signal, a means for setting a signal width detectable area, a counting means for counting the number of times the received activation request signal is received for each signal area of a predetermined width, and an activation counted by the counting means A storage unit that stores the number of receptions of the request signal for each predetermined signal width, and a signal that has the maximum number of receptions or exceeds a predetermined set value among the receptions for each predetermined signal width stored in the storage unit Signal width detectable area changing means for determining the width as a peak value and changing the set signal width detectable area to a signal width detectable area having a predetermined width centered on the peak value. Signal width detection possible A communication device for detecting said activation request signal to set the frequency.

  According to the present invention, when the communication width (time width) of the activation request signal from another communication device changes over time from the set value, the activation request signal detection width is set to the peak value of the communication width accordingly. By changing following automatic tracking, it is possible to prevent the activation request signal from being missed in the receiving-side communication device.

It is a block diagram which shows the structure of the radio | wireless handset which concerns on embodiment of the communication apparatus used as the reception side of the starting request signal of this invention. It is a figure which shows an example of a starting request | requirement signal width statistical counter table. 2 is added to the counter table data shown in FIG. 2. Further, the detection width distribution and the peak value of the activation request signal are displayed on the upper stage, the ratio (%) on the vertical axis, and the time ( It is the figure which added the bar graph shown taking ms). It is a figure similar to FIG. 3 which shows the case where the signal width | variety of the starting request signal received from the meter-reading meter has shifted | deviated from the standard value. FIG. 4 is a diagram similar to FIG. 3 when there are two peak values. It is a flowchart explaining the processing procedure until it detects an activation request signal, communicates with a meter-reading meter, and transmits the acquired data to a center. FIG. 7 is a flowchart of the subroutine of step S108 in the flowchart of FIG. 6. It is a figure which shows typically an example of the conventional meter-reading system. It is a figure which shows roughly the procedure for the communication setting performed between a meter-reading meter and a radio | wireless subunit | mobile_unit. It is a figure explaining the relationship between the signal width | variety of the starting request signal transmitted from a meter-reading meter, and the detection availability in the radio | wireless handset side.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a structure of a wireless slave device 2 according to an embodiment of a communication device on the receiving side of a start request signal of the present invention.
The wireless slave unit 2 controls the entire wireless slave unit 2 and includes a control unit 101 and a ROM (Read Only Memory) 102 that are configured by a CPU (Central Processing Unit) 101 that functions as a signal width detectable region changing unit of the present invention. A random access memory (RAM) 103, an operation unit 104, a display unit 105, a specific low-power wireless unit 106 that is a communication unit for communicating with the wireless master device 3 or the center 4, an antenna 107, and a transmission side of an activation request signal A meter-reading meter I / F (interface) 108 for connecting to a meter-reading meter, which is a communication device, and a power supply unit 109.

The ROM 102 stores a program for operating the CPU 101, for example, an automatic signal width tracking program for executing processing for changing the signal width detectable region.
The RAM 103 is storage means that functions as a temporary storage area for the operation of the CPU 101, and includes a startup request signal width statistical counter table (abbreviated as a counter table), and a detection value of the signal width of the startup request signal Save statistical data etc.
The operation unit 104 includes operation means such as a key, and performs device status confirmation, installation operation, and communication test of the wireless slave device.

The display unit 105 includes, for example, a display unit such as an LED, and displays an installation confirmation result, a test result display, and the like.
The specific low-power radio unit 106 functions as a communication unit that receives a request signal for meter reading data from an external communication device, that is, a wireless master unit or a center, and transmits meter reading data to the outside in response to the request signal.
The power supply unit 109 is configured by a battery or the like serving as a driving power source for the wireless slave unit.

  Note that the wireless slave device 2 of the present embodiment is provided with a period counter which is a counting means (not shown). This cycle counter is composed of a cycle timer that is output every time the data movement time required per unit data of the activation request signal from the meter-reading meter 1 and a counter that accumulates the outputs of the cycle timer are counted. To obtain the signal width (time; ms).

The wireless slave unit 2 counts the signal width when the “start-up request signal” is received through communication between the meter-reading meter 1 and the wireless slave unit 2 for each predetermined signal width by the period counter, and the count value is the signal width. It is stored (or accumulated) in a “counter table” in the RAM 103 provided for each time.
In the present embodiment, based on the detection width data (statistical data) stored in the “counter table”, as will be described later, the currently set signal width detectable area is set to the reception frequency (for each predetermined signal width ( From the (number of receptions), change and reset the part with a relatively high frequency as a reference. That is, the wireless slave device 2 automatically and variably controls the signal width detectable region in accordance with the distribution of the signal width of the reception signal (activation request signal) from the meter-reading meter.

Hereinafter, the process of automatically changing the signal width detectable region in the wireless slave device 2 according to the present embodiment will be described.
First, the counter table (start-up request signal width statistical counter table) will be described.
FIG. 2 is a diagram illustrating an example of a counter table (activation request signal width statistical counter table).
The counter table shows the result of measuring the signal width (detection width) of the activation request signal (activation request signal before detection) received by the wireless slave device 2 with a period counter, that is, the measured activation request signal width (time width, unit). ms) in a predetermined time width unit (100 ms unit in the illustrated example) and the ratio of the number of receptions in the time unit to the total number of receptions, that is, the detection width (ms), reception by the period counter The number of times and the overall ratio are accumulated.

Here, the detection width is the time width (ms (milliseconds)) of the signal width of the activation request signal received by the wireless slave unit 2 from the meter-reading meter 1. The reception number counter value is the total number of reception signals received from the meter-reading meter 1 of the wireless slave unit 2 measured by the period counter for each predetermined detection width (here, every 100 ms). The overall ratio is a numerical value indicating the ratio of the number of receptions for each predetermined detection width with respect to the total number of receptions in a certain period in%.
When a start request signal is received from the meter-reading meter 1 to the wireless slave unit 2, the cycle counter counts the signal width for each predetermined unit width of the signal width. The CPU 101 increments the “reception number counter value” for each predetermined detection width in the “counter table” by 1 (increment) and stores it in the RAM 103 for each output of the cycle timer. Further, the CPU 101 recalculates the reception ratio of the reception counter value for each predetermined detection width with respect to the total reception frequency, and stores it at the position of the corresponding counter value.

Next, a process for changing the signal width detectable region (specified value) based on the data accumulated in the counter table will be described.
FIG. 3 shows a display indicating that detection is not possible and can be further detected in the data of the counter table in FIG. 2. Further, the detection width distribution and peak value of the activation request signal are shown in the upper part, and the vertical axis indicates the ratio (%) and horizontal It is the figure which added the bar graph which took time (ms) on the axis | shaft and was shown.

FIG. 3 shows that the activation request signal entering the detectable region (signal width detectable region) is detected as an activation request signal, and conversely, it is not detected as an activation request signal outside this specified value.
In the overall ratio, the ratio of the number of receptions in the detection width to the total number of receptions is shown every 100 ms unit. In this example, the highest value (peak value) is 47%. Further, the detection width corresponding to this is the reference value A width (more than the reference value Ams and less than A + 100 ms), which contains a standard value.
According to this detection width data example of the counter table, the wireless slave unit 2 can detect 94% of the total number of receptions as an activation request signal. In addition, the ratio of non-detection is 6% in total, 3% below the reference value (minimum) and 3% above the reference value (maximum), but this detection width data is effective by setting the specified value according to the standard. This indicates that there is no problem.

FIG. 4 is a view similar to FIG. 3 showing a case where the signal width of the activation request signal received from the meter-reading meter is deviated from the standard value due to the meter-reading meter or due to the installation environment and secular change.
Here, a case is shown in which the peak value in the signal width (detection width) of the number of times of reception of the received activation request signal is shifted by −200 ms from the reference value of the specified value.
In this case, if the signal width detectable area of the wireless slave unit 2 is fixed to the signal width detectable area based on the standard value (specified area; reference value ± 200 ms), the total is less than the reference value (−200 ms) of 22%. Thus, a total of 25% of 3% exceeding the reference value (+200 ms) cannot be detected. That is, once every four times, the activation request signal from the meter-reading meter 1 side cannot be detected on the wireless slave unit side, and therefore communication between the two is not performed.

  Therefore, in the example of FIG. 4, the wireless slave unit 2 (the CPU 101) sets the reference value to the detection width (peak value) corresponding to the highest value (47%) of the reception frequency number (overall ratio) from the counter table. The new reference value ± 200 ms obtained by adding the error range to the new setting value, that is, the signal width detectable region is reset. When the standard value is likely to deviate due to the resetting, the setting value including the standard value can be used.

As for the accumulated amount such as the detection width of the counter table at the time of peak value selection, a predetermined value (or threshold) is provided for the total number of receptions so that a stable peak value can be selected, and the total number of receptions The peak value may be determined when the value exceeds the specified value.
Also, instead of the total number of receptions, the count value of the number of receptions during a certain period such as time and date (for example, 30 days) is stored, and the detection width with the largest count value is detected as the peak (center). It is good also as conditions which determine a field.

In addition, when determining the peak value, a specified value (or threshold value) is provided for the ratio to the whole, and only a value exceeding the specified value can be set as the peak value.
In this case, if there are multiple ratios exceeding the specified value (threshold value), the detection width (peak value 1) corresponding to the smallest one and the detection width (peak value 2) corresponding to the maximum peak. As a value, the “−error” portion is subtracted from the small peak value 1, and the “+ error” portion is added from the large peak value 2 to obtain a new signal width detectable region, and this changed signal width The activation request signal is detected based on the possible area.

FIG. 5 is a view similar to FIG. 3 when there are two peak values.
Also in this case, when the activation request signal is detected based on the signal width detectable area set on the wireless slave unit 2 side, 13% is less than the specified value (minimum), and 3% is more than the specified value (maximum), which is 16%. Will be missed on the wireless handset 2 side.
Therefore, here, based on the respective peak values 1 and 2, that is, the lower limit is a value obtained by subtracting an error of 200 ms from the peak value 1, and the upper limit is a region of the value obtained by adding the error of 200 ms to the peak value 2, that is, the peak value− The set signal width detectable region is changed with the region between 200 ms and the peak value 2 + 200 ms as the signal width detectable region. Thereby, the undetectable ratio is only 4% in total, that is, 1% of the lower limit side (peak value 1-200 ms) and 3% of the upper limit side (peak value 2 + 200 ms).

The signal width detectable region setting based on the peak value is performed when the communication tendency is stable (when the total number of receptions is equal to or more than a predetermined specified value). It is preferable to operate with a detection range within a meter (original) specified value.
In this way, by changing the set signal width detectable area and resetting a new signal width detectable area, the number of “start request signals” that deviate from the specified value is reduced as much as possible, and the start request signal is generated with high probability. Can be detected.

According to the present embodiment, the number of times of reception of the activation request signal generated in the installed site is counted and accumulated for each signal width, and based on the accumulated data, the signal width detectable area is set. When the communication width (time width) of the activation request signal from the meter-reading meter changes from the set value, the activation request signal detection width is automatically tracked and changed accordingly, and thereby the activation request signal in the wireless slave unit 2 is changed. Can be prevented from being overlooked. That is, even if the signal width of the “start-up request signal” changes slowly due to secular change after setting the signal width detectable area in the field, it is possible to set the signal width detectable area following the change.
Furthermore, since the setting including a plurality of peak values can be performed, detection with high probability is possible even when the detection width distribution of the detected activation request signal width is large.

Next, a control processing procedure performed on the wireless slave unit 2 side for setting the signal width detectable region described above will be described with reference to the accompanying drawings.
FIG. 6 is a flowchart for explaining a processing procedure from detection of an activation request signal to communication with the meter-reading meter 1 until transmission of acquired data to the center.
That is, first, a counter table provided in the RAM 103 of the wireless slave device 2 is initialized, and a signal width detectable region (effective detection width) is initialized with an initial reference value (S101).

  Here, it waits until the activation request signal is turned on (transmits) (S102, No). If the activation request signal is turned on (S102, Yes), the signal width count value of the period counter is reset (S103), After the fixed time has elapsed (S104), while the activation request signal is on (S105, Yes), the signal width count is incremented by 1 until the activation request signal is turned off (S106), and the process is repeated.

  If the activation request signal is not turned on in step S105 (S105, No), the signal width time is determined (S107), and then the signal width detectable region is checked (discriminated). In this step, a subroutine described in the flowchart of FIG. 7 is executed (S108). Thereafter, it is determined whether or not the activation request signal is within the signal width detectable region (effective detection width in the figure) (S109), and if it is within the signal width detectable region (effective detection width) (S109, Yes), the meter reading is performed. Communication with the meter is performed (S110). Here, if there is a response from the meter-reading meter and meter-reading meter communication is successful (S111, Yes), meter-reading meter acquisition data is transmitted to the center (S113), and the processing from step S102 is repeated.

  If the start request signal width is not within the signal width detectable region (effective detection region) in step S109 (S109, No), and if meter reading communication is not successful in step S111 (S111, No), Since the communication is failed (S114), the process returns to step S102 and is repeated.

FIG. 7 is a flowchart of the processing procedure of step S108 in the subroutine of the flow of FIG.
When the signal width (detection width; time) is determined in step S107 in FIG. 6, the CPU 101 increments the corresponding reception count (count value) in the counter table by 1 (S201), and increments the total number of detections by 1 (S202). Next, the total ratio of the counter table is recalculated and updated (S203). Here, when the total number exceeds the specified value (S204, Yes), since the number of data acquisition is sufficient, the ratio of the total number of receptions for each predetermined width to the total number of receptions (in the figure, the total ratio) ) Exceeds the specified value (S205, Yes), the peak value is stable. Next, if the peak value is singular (S206, No), “−error” is subtracted from the peak value. A time width (minimum effective width) is determined (S207), and a time width (signal width detectable region; maximum effective width in the figure) obtained by adding a time width corresponding to “+ error” to the peak value is determined. (S208), this process ends.
If the total number does not exceed the specified value in step S204 (S204, No), the number of data acquisitions is insufficient, and the peak value is not stable. Therefore, the signal width detectable region (maximum effective width, minimum effective width) ) Is not changed (S212), and this process ends.

As the statistical data stored in the counter table increases, it becomes difficult to follow small changes. Therefore, when the signal width detectable region is set from the detection width data (statistical data) accumulated in the counter table, the accumulated statistical data is reset. The reset timing may be the detection width data amount (for example, stored in the ring buffer as a maximum of 300 data and overwritten from the oldest one) or deleted after a certain number of days from the start of storage.
If there are a plurality of peak values in step S206 (S206, Yes), the minimum detection width: peak value 1 and the maximum detection width: peak 2 are determined from the detection width data in the counter table (S209). Next, the effective width minimum value obtained by subtracting the time width of −error from the time width of peak value 1 is determined (S210), and the time width of + error is added to the time width of peak value 2 and the effective width. The maximum value is determined (S211), the signal width detectable region is determined, and this process is terminated.

  In setting the signal width detectable region described above, the signal width detection region is set with a standard value when the wireless slave unit is initially installed. Therefore, for example, when an activation request signal having a signal width other than a specified value such as 700 ms or 1300 ms is received, the activation request is made until the signal width detectable area is changed by the detection width data (record data of the counter table). The signal may not be detected.

Therefore, at the time of initial setting, for example, a provisional operation period is provided, the activation request signal is received from the first several times (for example, about 10 times), and the detection signal width is determined with the detection frequency having a large number of times as a peak You can also.
Further, at the time of initial setting, a signal width detectable region in which ± error is added around the activation request signal received first may be set so as to follow the activation request signal received from the beginning.
Further, as described above, the width itself may be changed (widened or narrowed) so as to satisfy the standard value of the signal width detectable region as well as shifting the signal width detectable region according to the peak value. .

  DESCRIPTION OF SYMBOLS 1 ... Meter-reading meter, 2 ... Wireless cordless handset, 3 ... Wireless master phone, 4 ... Center, 101 ... CPU, 102 ... ROM, 103 ... RAM, 104 ... Operation unit, 105 ... display unit, 106 ... specific low-power radio unit, 107 ... antenna, 108 ... meter-reading meter I / F, 109 ... power supply unit.

Claims (8)

When the activation request signal of another communication device is received, the signal width of the activation request signal is detected, and the activation request signal can be detected only when the detected signal width is within a preset signal width detectable region Communication device,
Means for setting a signal width detectable region;
Counting means for counting the number of times of reception of the received activation request signal for each signal area of a predetermined width;
Storage means for storing the number of times of reception of the activation request signal counted by the counting means for each predetermined signal width;
Of the number of receptions for each of the predetermined signal widths stored in the storage unit, a signal width that is the maximum number of receptions or exceeds a predetermined set value is determined as a peak value, and the set signal width detectable region is determined as the peak. A signal width detectable area changing means for changing to a signal width detectable area having a predetermined width centered on a value;
Have
A communication apparatus for detecting the activation request signal by setting a changed signal width detectable region. The communication device according to claim 1,
The communication apparatus performs the determination of the peak value of the signal width on the condition that the number of receptions of the activation request signal exceeds a predetermined set value. The communication device according to claim 1,
The determination of the peak value of the signal width is a communication device that is performed every elapse of a predetermined period after setting the signal width detectable region. The communication device according to any one of claims 1 to 3,
The signal width detectable region changing means changes to a signal width detectable region including a region between the minimum peak value and the maximum peak value when there are a plurality of the peak values exceeding the predetermined set value. . The communication device according to any one of claims 1 to 4,
The communication apparatus according to claim 1, wherein the signal width is a time width, and the counting means is a period counter that counts the time width of the activation request signal. The communication device according to any one of claims 1 to 5,
The communication device is a wireless slave device electrically connected to a slave device in a meter reading system.   A meter-reading system comprising the communication device according to claim 6, a meter-meter and a center. When the activation request signal of another communication device is received, the signal width of the activation request signal is detected. When the detected signal width is within a preset signal width detectable region, the activation request signal can be detected. A drive signal detection method in a communication device,
A step of setting a signal width detectable region within a predetermined range centered on a specified value;
A counting step of counting the number of times the received activation request signal is received for each signal area of a predetermined width;
A storage step of storing the number of times of reception of the activation request signal counted in the counting step in a storage unit for each predetermined signal width;
Of the number of receptions for each of the predetermined signal widths stored in the storage unit, a signal width that is the maximum number of receptions or exceeds a predetermined set value is determined as a peak value, and the set signal width detectable region is determined as the peak. A signal width detectable region changing step for changing to a signal width detectable region having a predetermined width centered on a value;
Have
A drive signal detection method in a communication apparatus in which a changeable signal width detectable region is set to detect the activation request signal.

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