JP4471435B2 - Wireless meter reading system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless meter reading system for remotely measuring a meter such as a water meter, a gas meter, or a calorimeter by wireless communication.
[0002]
[Prior art]
1 and 2 show the configurations of a conventional wireless meter reading system, respectively. In the system of FIG. 1, by operating the parent device 1, wireless communication is performed with the child device 2 connected to the measuring device 3, and data of the measuring device 3 is collected.
[0003]
Further, in the wireless meter reading system of FIG. 2, by operating an external device 4 connected to the parent device 1, such as a handy terminal, a centralized meter reading board, a terminal network control device, etc., wireless communication is performed with the child device 2. And collect the data of the measuring instrument 3.
[0004]
However, in the conventional wireless meter reading system, the communication speed is not changed during the communication between the master unit and the slave unit. In general, the speed is 1200 bps or 2400 bps.
[0005]
Further, in the conventional wireless meter reading system, when starting wireless communication, the calling wireless device transmits a repetition signal of a specific pattern or ID as an activation signal in order to call the counterpart station.
[0006]
The called radio is intermittently receiving to reduce power consumption, and when the received signal matches a specific pattern or ID stored in it, it is determined that it is calling to itself. After the activation response is returned, data is exchanged between them.
[0007]
In addition, the intermittent reception operation can reduce the power consumption if it is shorter. For this reason, it is advantageous that each of the activation patterns and IDs of the activation signal is short. For example, when the activation signal is a repetitive signal of “0” and “1”, the repetition of “0” and “1” is repeated. May also exist in communication data other than the activation signal.
[0008]
Now, assuming that communication is performed between a certain parent device and a child device, a child device not related to this mistakes the “0” “1” signal present in the communication with the activation signal to itself, Incorrect startup.
[0009]
In such a wireless meter reading system, a battery is used as a power source. If a malfunction occurs, the battery will be consumed more than that, and the battery will run out before the specified operation period. There is a problem that it is necessary to install a battery having a larger capacity, resulting in an increase in cost.
[0010]
[Problems to be solved by the invention]
Accordingly, a first object of the present invention is to prevent erroneous activation by a signal other than the activation signal by making the communication speed other than the activation signal different from the activation signal.
[0011]
Also, the second purpose is to change the communication speed with the start signal from the master unit and the start information from the slave unit, so that when another master unit is transmitting the start signal, This is to prevent other slave units from erroneously starting when a slave unit is transmitting a start signal.
[0012]
Furthermore, the third object is to make it possible to further reduce the probability of erroneous activation by setting the communication speed of the activation signal to a communication speed that is not generally used.
[0013]
[Means for Solving the Problems]
In order to achieve the first and second objects , the invention according to claim 1 includes a master unit, a slave unit, and a measuring instrument connected to the slave unit, and there are a plurality of master units having overlapping communication areas. In order to call the other station between the master unit and the slave unit in a wireless meter reading system that performs wireless communication between each master unit and each slave unit and collects information such as the measurement value of the measuring instrument. And the transmission signal other than this activation signal are different in transmission speed, the activation signal for the parent device to call the child device, and the activation signal for the child device to call the parent device, It is characterized by changing the communication speed .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 3 shows a configuration of an embodiment of a wireless meter reading system to which the present invention is applied.
The first centralized board 5 collects the weighing data of the first weighing device 8 via the first parent device 6 and the first child device 7 connected thereto. The second centralized board 9 is connected to the second master unit 10 connected thereto and the second slave unit 11 or the third slave unit 13 via the second scale unit 12 or the third scale unit 14. Collect the weighing data.
[0018]
Here, in order to prepare for the start signal from the slave units 7, 11 and 13 in the normal standby state, each of the master units 6 and 10 receives intermittently, for example, receiving operation for 10 ms every 2 seconds. It is operating. In addition, in each slave unit, in order to prepare for an activation signal from the master unit, the reception operation is intermittently performed in the same manner.
[0019]
FIG. 4 shows a communication procedure between the parent device and the child device. The start signal is performed at a communication speed of 2400 bps, and other communication, that is, the start response, the data request, and the data response have a communication speed of 1200 bps.
[0020]
FIG. 5 shows an example of the activation signal. As the activation signal, the “ID” of the communication destination is transmitted following the repetition signal of “0” and “1” at 2400 bps.
[0021]
Hereinafter, an operation example will be described with reference to these drawings.
Now, it is assumed that the ID of each wireless device is “101” for the first parent device 6, “102” for the second parent device 10, “001” for the first child device 7, and the second child device 11. Is “002”, the third slave unit 13 is “003”, and the first master unit 6 receives the start signal when the meter reading data of the first measuring device 8 is collected from the first centralized board 5. Then, “010101...” Is transmitted for 2.1 seconds at a communication speed of 2400 bps, and then ID “001” is transmitted.
[0022]
In this example, the activation signal is received, and when “0101” is received, it is determined that “activation is present”. Therefore, the first child device 7, the second child device 11, the third child device 13, All the wireless devices of the second base unit 10 are determined to be “activated” and are in a state of waiting for reception of the subsequent ID. However, when receiving the ID, it is determined that “ID mismatch” except for the first handset 7 Return to the standby state.
[0023]
The first handset 7 returns an activation response to the first base unit 8 at a communication speed of 1200 bps, and thereafter communicates between the first base unit 6 and the first handset 7 as shown in FIG. And necessary data such as meter reading data of the first measuring instrument 8 is collected.
[0024]
While the first base unit 6 and the first handset 7 are transmitting and receiving data, the other radio units are in a standby state and performing an intermittent reception operation. At this time, even if “0101” is present in the 1200 bps data transmitted / received between the first master unit 6 and the first slave unit 7, the communication speed is different from the activation signal. As shown in FIG. 6, the other wireless device receives the signal at 2400 bps to wait for the activation signal, and the data is “00110011...”, Which is clearly different from “0101”. There is no false start.
[0025]
However, in this example, since the first slave unit 7 is called, the second master unit 10 that is not related to the activation signal transmitted by the first master unit 6 may also determine that “there is activation”. is there.
[0026]
Therefore, the communication speed of the activation signal is 2400 bps when calling the slave unit from the master unit as shown in FIG. 7A, and 4800 bps when calling the master unit from the slave unit as shown in FIG. 7B. Thus, even if the first parent device 6 transmits the 2400 bps activation signal “010101...” In order to activate the first child device 7, the second parent device 10 receives the signal from the child device. Waiting for a 4800 bps activation signal “010101...”, The same reasoning as in the previous example, and no erroneous activation occurs due to this difference in communication speed. Further, when the child device activates the parent device, another child device is prevented from being erroneously activated for the same reason.
[0027]
Furthermore, by setting the communication speed of the activation signal to a unique speed such as 3200 bps or 8600 bps other than the communication speed generally used for communication such as 1200, 2400, and 4800 bps, the same system of other manufacturers and other wireless devices By data communication, it is possible to prevent accidental reception of data that matches the determination condition for starting the parent device or the child device.
[0028]
In this embodiment, 4 bits of “0101” are set as a condition for starting the parent device and the child device. However, the number of bits is not changed, and “0” and “1” are not simply repeated. Data having a specific meaning, such as “5531”, may be used.
[0029]
Furthermore, in the determination of the activation signal, in this example, the determination is performed once. However, in order to improve certainty, the activation signal may be activated when received a plurality of times.
[0030]
In addition, although “ID following“ 010101... ”Is used as the activation signal, it is not limited to ID, and may be meter reading value request data, for example.
[0031]
【The invention's effect】
(1) Effect for Claim 1 By making the communication speeds different from those other than the activation signal, it is possible to prevent erroneous activation with a signal other than the activation signal, and to reduce power consumption.
[0032]
In addition, by changing the communication speed with the start signal from the master unit and the start signal from the slave unit, when another master unit is sending the start signal, another master unit or a slave unit is starting signal It is possible to prevent other slave units from erroneously starting up when transmitting, and further reduce power consumption.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a conventional wireless meter reading system.
FIG. 2 is a configuration diagram of a conventional wireless meter reading system that performs meter reading using an external device.
FIG. 3 is a configuration diagram of a wireless meter reading system to which the present invention is applied.
FIG. 4 is a sequence diagram showing a relationship between a communication procedure and a communication speed between the parent device and the child device in the present invention.
FIG. 5 is a timing chart showing an example of a start signal.
FIG. 6 is a timing chart showing that the timings of the start signal and other signals are different.
FIG. 7 is a sequence diagram showing that the communication speed when calling a child device from the parent device is different from the communication speed when calling the parent device from the child device. FIG. 7 (a) shows a case where the child device is called from the parent device. , (B) is a case where the master unit is called from the slave unit.
[Explanation of symbols]
5.9 Centralized panel 6/10 Master unit 7, 11, 13 Slave unit 8, 12, 14 Weighing instrument

Claims (1)

Consists of a parent device, a child device, and a measuring instrument connected to the child device, when there are multiple parent devices with overlapping communication areas, perform wireless communication between each parent device and each child device, In a wireless meter reading system that collects information such as weighing values of a measuring instrument,
The communication speed between the start signal for calling the other station between the master unit and the slave unit and the transmission / reception signal other than this start signal are different,
A wireless meter-reading system, characterized in that the communication speed is changed between a start signal for the master unit to call the slave unit and a start signal for the slave unit to call the master unit .

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