JP6926865B2 - Remote monitoring system - Google Patents

Description

The present invention relates to a remote monitoring system having a center device, a master unit, and a plurality of slave units having a multi-stage configuration, and the center device collects monitoring information acquired by each slave unit via the master unit.

It has a center device, a master unit, and a plurality of slave units in a multi-stage configuration, and centers the monitoring information (meter reading value of gas meter and water meter, gas leak alarm, low battery level alarm, etc.) acquired by each slave unit. There is a remote monitoring system in which a device collects information via a master unit (Patent Document 1).

In this remote monitoring system, communication between the center device and the master unit is performed by a wireless or wired public communication line (carrier line), and "master unit-1st stage slave unit-2nd stage slave unit -...- N". Communication between "stage slave units" is performed by specified low power radio. Each slave unit transmits monitoring information to the center device via the upper slave unit, that is, the upper slave unit is used as a relay slave unit via the master unit, and a large amount of monitoring information is collected by the multi-stage configuration. Is possible.

In this remote monitoring system, a plurality of communication routes from the slave unit to the master unit are set. The center device registers a communication route obtained from each slave unit, that is, a plurality of communication routes in which the number of relay stages from the master unit is usually up to 2 stages (the lowest is the 3rd stage). After registering the communication route, the handset that has acquired the monitoring information (calling source handset) sends the monitoring information to the nearest handset on the registered highest priority communication route, and the above-mentioned handset that receives this (the handset) The relay slave unit) also performs the same operation, and transmits the above monitoring information to the center device via the master unit.

By the way, in these conventional remote monitoring systems, the monitoring information generated by a certain slave unit does not reach the relay slave unit or the master unit due to a communication failure caused by an environmental change or a device failure, and the center device sends the monitoring information. It may not be possible to obtain it. Further, although the monitoring information has arrived at the center device, the monitoring information acquisition completion notification returned by the center device may not reach the calling source slave unit of the monitoring information.

In such a case, the calling source slave unit changes the communication route, selects the nearest higher slave unit in the next rank, and makes a re-call. This communication route change operation is repeated until the monitoring information acquisition completion notification transmitted from the center device is received from the nearest higher-level slave unit.

Therefore, if the cause of such a communication failure is left unattended, communication between the slave units or between the master unit and the slave unit may be performed more than necessary, which may interfere with the operation service. It is desirable to identify the location of the device failure and improve it.

Japanese Unexamined Patent Publication No. 2009-237964

The present invention has been made to solve such a problem, and an object of the present invention is to have a center device, a master unit, and a plurality of slave units having a multi-stage configuration, and monitoring acquired by each slave unit. In a remote monitoring system in which the center device collects information via the master unit, it is possible to detect a slave unit causing a communication failure.

The present invention has a center device , a master unit each of which is a wireless terminal, and a plurality of slave units having a multi-stage configuration, and each slave unit transmits acquired monitoring information to the center device via a higher-level wireless terminal. In the remote monitoring system, the center device communicates with the wireless terminal directly above each slave unit added to the monitoring information notification message transmitted from each slave unit via the master unit. The communication status information representing the above is acquired, and it is determined that the slave unit whose value of the communication status information matches the predetermined threshold condition for a predetermined period of time is causing a communication failure, and the communication status information is described. Includes the same number of times the message is resent, and if the number of times the same message is resent added to the monitoring information report message sent at the time of this report matches the predetermined threshold condition, the next time the report is abandoned. Monitoring information transmitted at the time of notification This is a remote monitoring system in which the number of times the same message is resent added to the notification message is set to a specific value indicating that the notification has been abandoned.

According to the present invention, in a remote monitoring system having a center device, a master unit, and a plurality of slave units having a multi-stage configuration, and the center device collects monitoring information acquired by each slave unit via the master unit. It is possible to detect a slave unit that is causing communication failure. Further, according to the present invention, in the center device, when the number of times the same message is retransmitted added to the monitoring information report message received at the time of the next report is a specific value, the slave unit gives up this report. Can be recognized.

It is a figure which shows the structure of the remote monitoring system which concerns on embodiment of this invention. It is a block diagram which shows the schematic structure of a slave unit. It is a block diagram which shows the schematic structure of a master unit. It is a block diagram which shows the schematic structure of a center device. It is a figure which shows the example of the format of the communication status table held by the 2nd stage slave unit. It is a figure which shows the procedure which the 2nd stage slave unit acquires the reception level of the radio wave from the 1st stage slave unit, and the example of the reception level acquired by the procedure. It is a figure which shows the example of the procedure which the slave unit of the 2nd stage retransmits the same telegram, and the number of times of the same telegram retransmission held by the procedure. It is a figure which shows the example of the terminal communication status table held by a center apparatus. It is a figure which shows the example of the meter reading value report telegram transmitted from the master unit to the center apparatus, and the terminal communication status table updated by the center apparatus by receiving the telegram. It is a figure which shows the procedure when the report of the meter reading value from the second-stage handset succeeds in the first retransmission, and the number of times of the same telegram retransmission in the terminal communication status table in that case. It is a figure which shows the procedure when the report of the meter reading value from the 2nd stage slave unit succeeds in the 4th retransmission, and the number of times of the same telegram retransmission in the terminal communication status table in that case. It is a figure for demonstrating the warning display which a center apparatus performs when the state which the transmission level of the 2nd stage slave unit matches a threshold value condition is continuous for a predetermined period. It is a figure for demonstrating the warning display which a center apparatus performs when the state which the reception level of the 2nd stage slave unit matches a threshold condition is continuous for a predetermined period. It is a figure for demonstrating the warning display which a center apparatus performs when the state which the transmission / reception level difference of the 2nd stage slave unit matches a threshold value condition is continuous for a predetermined period. It is a figure for demonstrating the warning display which a center apparatus performs when the state which the same telegram retransmission count of the 2nd stage slave unit matches a threshold value condition is continuous for a predetermined period. The procedure when the second-stage slave unit reports the meter reading value and can receive the meter reading value acquisition completion notification from the center device and the procedure when the retransmission is abandoned due to poor communication with the first-stage slave unit are shown. It is a figure. In the procedure shown in FIG. 16, the contents of the communication status table of the second-stage slave unit when the second-stage slave unit transmits the meter reading value notification message to the first-stage slave unit, and the contents of the meter reading value notification message are shown. It is a figure. FIG. 6 is a diagram showing the contents of the communication status table of the second-stage slave unit when the second-stage slave unit receives an ACK message from the first-stage slave unit in the procedure shown in FIG. In the procedure shown in FIG. 16, a diagram showing the contents of the communication status table of the first-stage slave unit when the first-stage slave unit sends a meter reading value notification telegram to the master unit, and the contents of the meter reading value notification telegram. be. In the procedure shown in FIG. 16, the contents of the communication status table of the first-stage slave unit when the first-stage slave unit receives the ACK message from the master unit, and the meter reading value notification message transmitted by the master unit to the center device. It is a figure which shows the content. FIG. 6 is a diagram showing the contents of a terminal communication status table held by a center device that has received a meter reading value notification telegram from a master unit in the procedure shown in FIG. In the procedure shown in FIG. 16, the figure shows the number of times the same telegram is resent in the communication status table of the second-stage slave unit when the second-stage slave unit can receive the meter reading value acquisition completion notification and when the retransmission is abandoned. be. When the second-stage slave unit notifies the meter reading value in response to the request from the center device, the procedure when the center device can acquire the meter reading value by retransmitting the second meter reading value request, and the communication status table of the center device. It is a figure which shows the number of times of continuous failure of telegram transmission in. It is a figure for demonstrating the warning display which a center apparatus performs when the state which the number of continuous failure of telegram transmission caused by a center matches a threshold value condition is continuous for a predetermined period. It is a figure which shows the procedure which the 2nd stage slave unit reports a meter reading value in response to a request from a center apparatus. In the procedure shown in FIG. 25, it is a figure which shows the meter reading value request message transmitted by the center apparatus to a master unit, and the meter reading value request message transmitted by a master unit to a first-stage slave unit. In the procedure shown in FIG. 25, the reception level in the communication status table of the first-stage slave unit when the first-stage slave unit receives the meter reading value request message from the master unit, and the first-stage slave unit is the second-stage slave unit. It is a figure which shows the meter reading value request telegram to be transmitted to. In the procedure shown in FIG. 25, the reception level in the communication status table of the second-stage slave unit when the second-stage slave unit receives the meter reading value request message from the first-stage slave unit, and the second-stage slave unit is the first stage. It is a figure which shows the meter reading value response telegram transmitted to the handset of an eye. In the procedure shown in FIG. 25, the reception level in the communication status table of the second-stage slave unit when the second-stage slave unit receives the ACK message from the first-stage slave unit, and the first-stage slave unit transmits to the master unit. It is a figure which shows the meter reading value response telegram. In the procedure shown in FIG. 25, the reception level in the communication status table of the first-stage slave unit when the first-stage slave unit receives the ACK message from the master unit, and the meter reading value response message transmitted by the master unit to the center device. It is a figure which shows. FIG. 5 is a diagram showing transmission / reception levels of the second-stage slave unit and the first-stage slave unit in the terminal communication status table of the center device that received the meter reading value response telegram from the master unit in the procedure shown in FIG. 25.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of remote monitoring system>
FIG. 1 is a diagram showing a configuration of a remote monitoring system according to an embodiment of the present invention.
This remote monitoring system is used, for example, for automatic meter reading of gas and water meters, and is a two-stage configuration of a center device 1 and a wireless terminal provided in each meter reading device (meter, etc.). The meter reading values from the machines (4 handsets 3-1a to 3-1d in the 1st stage and 5 handsets 3-2a to 3-2e in the 2nd stage) and the meter readings from the handsets are relayed to the center device 1. It consists of a master unit 2 which is a wireless terminal. The master unit 2 is connected to the center device 1 via a public communication line NW such as a mobile phone line. In the following description, when the slave units for each stage are not distinguished, the slave units 3-1 and 3-2 are used, and when the slave units are not distinguished, the slave units 3 are used.

The master unit 2 can communicate with the slave unit 3 by the specific low power radio, and the slave units 3 can also communicate with each other by the specific low power radio. Further, the slave unit 3 transmits the meter reading value to the center device 1 via the master unit 2, and the multi-stage configuration (here, two stages) enables more meter reading values to be collected.

In the present embodiment, the slave units 3-1a to 3-1d are connected to the first stage of the number of relay stages, that is, the stage directly below the master unit 2. Further, in the second stage of the number of relay stages, the slave units 3-2a and 3-2b are connected directly under the slave unit 3-1a, and the slave units 3-2b and 3-2c are directly under the slave unit 3-1b. It is connected, and the slave units 3-2c and 3-2d are connected directly under the slave unit 3-1c, and the slave units 3-2d and 3-2e are connected directly under the slave unit 3-1d. The second-stage slave units 3-2a to 3-2e are terminal slave units to which no slave unit is connected directly under the slave unit 3-2a to 3-2e.

In other words, the wireless terminal directly above the first-stage slave units 3-1a to 3-1d is the master unit 2. Regarding the second-stage slave unit, the wireless terminal directly above the slave unit 3-2a is the slave unit 3-1a, and the wireless terminal directly above the slave unit 3-2b is the slave units 3-1a and 3-1b. The wireless terminals directly above the handset 3-2c are the handset 3-1b and 3-1c, and the wireless terminals directly above the handset 3-2d are the handset 3-1c and 3-1d, and the handset 3-2e. The upper wireless terminal is the slave unit 3-1d.

<Structure of slave unit>
FIG. 2 is a block diagram showing a schematic configuration of the slave unit 3 in FIG.
As shown in the figure, the slave unit 3 includes a control unit 31, a storage unit 32 connected to the control unit 31, a wireless transmission / reception unit 33, an external I / F (interface) unit 34, a display unit 35, and an operation input. The unit 36 is provided. An antenna 37 is connected to the wireless transmission / reception unit 33.

The control unit 31 is composed of, for example, a microprocessor and peripheral circuits thereof, and controls the entire slave unit 3 and performs arithmetic processing and the like.

The storage unit 32 includes a non-volatile memory such as a ROM, a rewritable non-volatile memory such as a flash memory, and a volatile memory such as a RAM. The ROM stores a control program necessary for operating the slave unit 3. In addition, each program being executed by the control unit 31 and information necessary for executing the program (terminal number, wireless channel, electric field strength, number of relay stages of own terminal, various tables, etc.) are stored in the RAM. In addition, various setting data and the like are stored in the rewritable non-volatile memory. Here, the communication status table 321 that holds the communication status information including the reception level, the transmission level, and the same number of times the telegram is retransmitted of the own terminal is shown. Details of these communication status information will be described later.

The wireless transmission / reception unit 33 performs wireless communication with another slave unit 3 and the master unit 2 by a specific low power radio. An external device such as a meter for gas or water is connected to the external I / F unit 34, and the meter reading value detected by these external devices is acquired periodically or in response to a request from the center device 1. The display unit 35 is a user I / F that is composed of LEDs or the like and displays an operating state or the like of the slave unit 3. The operation input unit 36 includes buttons, switches, and the like, and is a user I / F for inputting a predetermined setting for the slave unit 3. The antenna 37 transmits and receives radio waves.

<Configuration of master unit>
FIG. 3 is a block diagram showing a schematic configuration of the master unit 2 in FIG.
The master unit 2 includes a control unit 21, a storage unit 22, a wireless transmission / reception unit 23, a network control unit 24, a display unit 25, and an operation input unit 26, each of which is connected to the control unit 21. An antenna 27 is connected to the wireless transmission / reception unit 23.

The control unit 21 is composed of, for example, a microprocessor and peripheral circuits thereof, and controls the entire master unit 2 and performs arithmetic processing and the like.

The storage unit 22 includes a non-volatile memory such as a ROM, a rewritable non-volatile memory such as a flash memory, and a volatile memory such as a RAM. The ROM stores a control program and the like necessary for operating the master unit 2. In addition, each program being executed by the control unit 21 and information necessary for executing the program (terminal number, wireless channel, electric field strength, various tables, etc.) are stored in the RAM. In addition, various setting data and the like are stored in the rewritable non-volatile memory.

The wireless transmission / reception unit 23 performs wireless communication with the slave unit 3 by the specified low power radio. The network control unit 24 communicates with the center device 1 via the public communication line NW.
The display unit 25 is composed of LEDs and the like, and displays the operating state and the like of the master unit 2. The operation input unit 26 includes buttons, switches, and the like, and is a user I / F for inputting a predetermined setting for the master unit 2. The antenna 27 transmits and receives radio waves. As with the slave unit 3, an external I / F unit may be provided so as to acquire the meter reading value.

<Configuration of center device>
FIG. 4 is a block diagram showing a schematic configuration of the center device 1 in FIG.
The center device 1 includes a control unit 11, a storage unit 12, a network control unit 13, a display unit 14, and an operation input unit 15, each of which is connected to the control unit 11.

The control unit 11 is composed of, for example, a microprocessor and peripheral circuits thereof, and controls the entire center device 1 and performs arithmetic processing and the like.

The storage unit 12 includes a non-volatile memory such as a ROM, a rewritable non-volatile memory such as a flash memory or a hard disk, and a volatile memory such as a RAM. The ROM stores a control program and the like necessary for operating the center device 1. In addition, each program being executed by the control unit 11 and information necessary for executing the program are stored in the RAM. In addition, the rewritable non-volatile memory communicates with the terminal number of each slave unit 3 registered, the management data table consisting of information about the external device connected to each slave unit 3, the terminal number of the master unit 2, and the like. In addition to the information about the system required for the system, data of an external device transmitted from the master unit 2 and the like are stored.

Here, the terminal communication status table 121 that holds the terminal communication status information including the reception level, the transmission level, and the same number of times the telegram is retransmitted of the slave unit 3 and the communication status of the slave unit 3 are monitored, resulting in a communication failure. The monitoring threshold table 122 that holds the thresholds of the reception level, the transmission level, the transmission / reception level difference, the number of times of the same message retransmission, and the number of times of continuous failure of the message caused by the center, which is used to identify the slave unit 3, is shown. Here, the number of continuous telegram failures caused by the center means that the center device 1 requests the slave unit 3 to report the meter reading value and controls the slave unit 3 via the master unit 2. The number of consecutive failures of the transmitted telegram. Details of these thresholds will be described later.

The network control unit 13 communicates with the master unit 2 via the public communication line NW.
The display unit 14 is, for example, a liquid crystal display (LCD), and displays information about the system, information about an external device connected to the slave unit 3, an operation screen at the time of input to the center device 1, and the like. The operation input unit 15 has input means such as a keyboard and a mouse for inputting various data and commands to the center device 1 from the outside.

<Communication status table held by the second-stage handset>
FIG. 5 is a diagram showing an example of the format of the communication status table held by the second-stage slave unit 3-2.

In this communication status table 3211, when the second-stage slave unit 3-2 has three first-stage slave units 3-1a, 3-1b, 3-c as communication partner terminals, that is, directly higher-level terminals serving as relay terminals. This is an example. The communication status table 3211 holds the reception level of radio waves from the three communication partner terminals (here, 9, 9, 8) and the number of times the same telegram is retransmitted (here, 0).

<Acquisition of reception level in communication status table>
FIG. 6 is a diagram showing a procedure in which the second-stage slave unit acquires the reception level of radio waves from the first-stage slave unit, and an example of the reception level acquired in the procedure.

When the slave unit 3-2 receives the ACK message from the slave unit 3-1a after transmitting the meter reading value notification message to the slave unit 3-1a (procedure S1) (procedure S2), the reception level thereof. (Here, 10) is stored in the communication status table 3211 (overwrites the state shown in FIG. 5) as the reception level of the slave unit 3-2 when the slave unit 3-1a is used as the communication partner terminal.

<Acquisition of the same message retransmission count in the communication status table>
FIG. 7 is a diagram showing an example of a procedure in which the second-stage slave unit retransmits the same telegram and the number of times the same telegram is retransmitted held in the procedure.

The slave unit 3-2 could not receive the ACK message from the slave unit 3-1a after the first transmission of the meter reading value notification message (procedure S01) to the slave unit 3-1a.
Therefore, the slave unit 3-2 transmits the first meter reading value notification telegram to the slave unit 3-1b (procedure S11), and stores 1 in the same number of times the telegram is resent in the communication status table 3211.

The slave unit 3-1b transmitted an ACK telegram to the slave unit 3-2 (procedure S12), and then transmitted a meter reading value notification telegram to the master unit 2 which is the immediate higher terminal (procedure S13). The master unit 2 transmitted a meter reading value notification telegram to the center device 1 (procedure S14).

When the center device 1 receives the meter reading value notification telegram, it stores it in the meter reading value management table (not shown) in the storage unit 12 and transmits the meter reading value acquisition completion notification telegram to the master unit 2 (procedure S15). .. The master unit 2 transmits a meter reading value acquisition completion notification telegram to the slave unit 3-1b (procedure S16).

The slave unit 3-1b transmitted a meter reading value acquisition completion notification telegram to the slave unit 3-2 (procedure S17). However, due to poor communication, the handset 3-2 could not receive the meter reading value acquisition completion notification telegram.
Therefore, the slave unit 3-2 transmits the second meter reading value notification telegram to the slave unit 3-1c (procedure S21), and stores 2 in the same number of times the telegram is resent in the communication status table 3211.

The slave unit 3-1c transmitted an ACK telegram to the slave unit 3-2 (procedure S22), and then transmitted a meter reading value notification telegram to the master unit 2 which is the immediate higher terminal (procedure S23). The contents of the subsequent procedures S24 to S26 are the same as the contents of the procedures S14 to S16.

The content of the next procedure S27 is the same as the content of the procedure S17. However, in step S17, the handset 3-2 could not receive the meter reading value acquisition completion notification telegram due to poor communication, whereas in step S27, the handset 3-2 could receive the meter reading value acquisition completion notification telegram. Therefore, the slave unit 3-2 clears the number of times of retransmitting the same message in the communication status table 3211 to 0.

The description of updating the reception level of the slave unit 3-1b based on the reception level of the ACK message in step S12 and updating the reception level of the slave unit 3-1c based on the reception level of the ACK message in procedure S22 has been omitted. Further, the description of the ACK telegrams for each of the procedures S13 to S16 and the procedures S23 to S27 is omitted.

<Terminal communication status table held by the center device>
FIG. 8 is a diagram showing an example of a terminal communication status table held by the center device.

The terminal communication status table 121 is created and held for each terminal. The figure is a terminal communication status table 1211 for the slave unit 3-2, that is, the terminal slave unit. The terminal communication status table 1211 sets the transmission level and reception level when the slave units 3-1a, 3-1b, and 3-1c, which are the higher-level routes (directly higher-level terminals) of the slave unit 3-2, are communication partner terminals. Transmission / reception level tables 12111, 12112, 12113 that are linked to information and held, the same message retransmission count table 12114 that holds the same message retransmission count of the slave unit 3-2 linked to time information, and continuous failure of message transmission due to the center. It is provided with a center-induced message transmission continuous failure count table 12115 that holds the number of times in association with the first failure date and time and the last failure date and time.

Here, the reception level in the transmission / reception level tables 12111, 12112, and 12113 is the reception level of the radio waves from the slave units 3-1a, 3-1b, and 3-1c in the slave unit 3-2, that is, the communication of FIGS. 5 to 7. It corresponds to the reception level stored in the status table 3211. The transmission level in the transmission / reception level tables 12111, 12112, and 12113 is a level acquired as the reception level of the radio waves from the slave units 3-2 in the slave units 3-1a, 3-1b, and 3-1c. When the first-stage slave unit is added, the transmission / reception level table for the slave unit is added, and when the first-stage slave unit is removed, the transmission / reception level table for the slave unit is deleted.

The number of retransmissions stored in the same telegram retransmission count table 12114 corresponds to the number of retransmissions stored in the communication status table 3211 of FIGS. 5 to 7. The number of retransmissions is the total number of retransmissions regardless of the relay route of the slave unit 3-2.

In the center-induced telegram transmission continuous failure count table 12115, although the center device 1 requested the second-stage slave unit 3-2 to report the meter reading value via the master unit 2 and the first-stage slave unit 3-1. Holds information in case of continuous failure. Here, it indicates that the first request made at 12:00 on April 1, 2017 to the final request made at 19:00 on April 20, 2017 have failed 10 times in a row. There is.

<Creating a terminal communication status table>
FIG. 9 is a diagram showing an example of a meter reading value notification telegram transmitted from the master unit to the center device and a terminal communication status table updated by the center device upon receiving the telegram.

The telegram 41 is a meter reading value notification telegram transmitted by the master unit 2 to the center device 1, and is the meter reading value of the slave unit 3-2 and the communication status information of the slave unit 3-2 (retransmission count = 5th, slave unit 3-). The previous reception level of 2 = 5, the previous reception level of the slave unit 3-1c = 9), and the transmission level of the slave unit 3-2 and the transmission level of the slave unit 3-1c as the transmission route information (transmission level). include.

Here, the previous reception level of the slave unit 3-2 and the transmission level of the slave unit 3-2 are ACKs for the meter reading value report telegram transmitted by the slave unit 3-2 to the slave unit 3-1c, respectively, as described above. The reception level of the telegram slave unit 3-2 and the reception level of the meter reading value report telegram transmitted by the slave unit 3-2 to the slave unit 3-1c.

Further, the previous reception level of the slave unit 3-1c and the transmission level of the slave unit 3-1c are set in the slave unit 3-1c of the ACK message for the meter reading value notification message transmitted by the slave unit 3-1c to the master unit 2, respectively. The reception level is the reception level of the meter reading value report message transmitted by the slave unit 3-1c to the master unit 2 in the master unit 2.

The telegram 41 was received by the center device 1 at 15:00:00 on March 18, 2017. Depending on the previous reception level (= 5) and transmission level (= 5) of the slave unit 3-2 included in the telegram 41, the center device 1 has the transmission / reception level in the terminal communication status table 1211 for the slave unit 3-2. The reception level and transmission level of the slave unit 3-1c in Table 12113 are added. Further, depending on the previous reception level and transmission level of the slave unit 3-1c included in the telegram 41, the center device 1 causes the master unit 2 of the transmission / reception level table 12121 in the terminal communication status table 1212 for the slave unit 3-1c. Add the receive level and send level of.

<First example of the same message resending procedure>
FIG. 10 is a diagram showing a procedure when the meter reading value is successfully reported from the second-stage slave unit in the first retransmission and the number of times the same telegram is resent in the terminal communication status table in that case.

The slave unit 3-2 transmitted a meter reading value notification telegram to the slave unit 3-1c in step S101 as the first notification. The meter reading value notification telegram was transmitted to the master unit 2 in the procedure S102, and was transmitted to the center device 1 in the procedure S103. However, since the center device 1 could not receive the meter reading value notification telegram, the meter reading value acquisition completion notification telegram was not transmitted, and the slave unit 3-2 could not receive the meter reading value notification acquisition notification telegram.

Therefore, the slave unit 3-2 transmitted the meter reading value report telegram in step S104 as the first retransmission. This meter reading value notification telegram was transmitted to the center device 1 via the master unit 2 in steps S105 and 106. This meter reading value reporting telegram includes the number of retransmissions (here, 1) as in the meter reading value reporting telegram 41 described with reference to FIG. 9, and the center device 1 holds the slave unit 3-2. The same telegram retransmission count table 12114 in the terminal communication status table 1211 for the user stores the same telegram retransmission count as the telegram reception time, and sends a meter reading value acquisition completion notification telegram to the master unit 2 (procedure S107). This meter reading value acquisition completion notification telegram was transmitted to the slave unit 3-2 via the slave unit 3-1c (procedures S108 and S109).

<Second example of the same message resending procedure>
FIG. 11 is a diagram showing a procedure when the meter reading value is successfully reported from the second-stage slave unit in the fourth retransmission and the number of times the same telegram is resent in the terminal communication status table in that case.

In this figure, the contents of procedures S201 to S205 are the same as the contents of procedures S104 to S108 in FIG. In the next procedure S206, similarly to the procedure S109, the slave unit 3-1c transmits a meter reading value acquisition completion notification telegram to the slave unit 3-2. However, the slave unit 3-2 could not receive the meter reading value acquisition completion notification telegram.

Therefore, the slave unit 3-2 transmitted the meter reading value report telegram in step S207 as the second retransmission. The meter reading value notification telegram was transmitted to the master unit 2 in step S208, and was transmitted to the center device 1 in step S209. However, as in the case of the first notification in FIG. 10, since the center device 1 could not receive the meter reading value notification telegram, the meter reading value acquisition completion notification telegram was not transmitted, and the slave unit 3-2 sent the meter reading value notification acquisition notification telegram. Could not receive.

Therefore, the slave unit 3-2 transmitted the meter reading value notification telegram in step S210 as the third retransmission. The meter reading value notification telegram was transmitted to the master unit 2 in step S211 and to the center device 1 in step S212. However, this time as well as the previous time, the center device 1 could not receive the meter reading value notification telegram, so the meter reading value acquisition completion notification telegram was not transmitted, and the slave unit 3-2 could not receive the meter reading value notification acquisition notification telegram. rice field.

Therefore, the slave unit 3-2 transmitted the meter reading value notification telegram in step S213 as the fourth retransmission. The meter reading value notification telegram was transmitted to the center device 1 via the master unit 2 in steps S214 and 215. This meter reading value notification telegram includes the number of retransmissions (here, 4) as in the telegram 41 described with reference to FIG. 9, and the center device 1 has terminal communication with the handset 3-2 held by the center device 1. The same telegram retransmission count table 12114 in the status table 1211 stores (overwrites) the same telegram retransmission count as the telegram reception time, and sends a meter reading value acquisition completion notification telegram to the master unit 2 (procedure S216). This meter reading value acquisition completion notification telegram was transmitted to the slave unit 3-2 via the slave unit 3-1c (procedures S217 and S218).

<Monitoring and warning display of the communication status of the slave unit performed by the center device>
The center device 1 has a transmission level, a reception level, a transmission / reception level difference, and the same message based on the communication status information (reception level, transmission level, number of times of same message retransmission) held in the terminal communication status table 121 for each slave unit. Monitor the number of retransmissions. Then, it is compared with each threshold value set and held in the monitoring threshold value table 122, and when a predetermined condition is satisfied, it is determined that the communication is defective and a warning is displayed.

That is, for example, the threshold conditions are transmission level: less than 4, reception level: less than 4, transmission / reception level difference: 5 or more, and number of same message retransmissions: 5 times or more. Then, it is determined whether or not the threshold condition is met for each monitoring target information, and if it is met, it is set as a continuous monitoring target. When the slave unit subject to continuous monitoring continuously meets the threshold value for a predetermined period (number of days or number of days; 15 days or more in this embodiment), a warning is displayed on the display unit 14 of the center device 1. .. Even if it becomes a continuous monitoring target, if the threshold condition is not met at the next communication, the warning is not displayed and it is excluded from the continuous monitoring target. Hereinafter, the transmission level, the reception level, the transmission / reception level difference, and the number of times the same message is retransmitted will be described in this order.

<< Transmission level threshold monitoring and warning display >>
FIG. 12 is a diagram for explaining a warning display performed by the center device when a state in which the transmission level of the second-stage slave unit matches the threshold value condition is continuous for a predetermined period of time. Here, FIG. 12A shows a transmission / reception level table 12111 when the slave unit 3-1a in the terminal communication status table 1211 for the slave unit 3-2 held by the center device 1 is a communication partner terminal, and FIG. 12B shows a center. The warning display 141 performed by the device 1 is shown.

As shown in FIG. 12A, in the transmission / reception level table 12111, the transmission level became 3 on January 10, 2017, which matched the threshold condition, and thus became a continuous monitoring target. The threshold condition is also met at the time of the next communication (January 15, 2017, 5 days later), and the threshold condition is also met at the time of the next communication (January 26, 2017, 16 days later). That is, the transmission level of the slave unit 3-2 matches the threshold condition continuously for a predetermined period after being the target of continuous monitoring.

Therefore, the display unit 14 of the center device 1 displays the warning display 141 shown in FIG. 12B, that is, at 16:00 on January 26, 2017, which is the final communication time, the handset 3-2, which is a poor communication terminal, and the communication partner. A warning display is performed in a mode in which the slave unit 3-1a, which is a terminal, and the transmission level threshold value, which is a cause of communication failure, are included as display contents.

<< Reception level threshold monitoring and warning display >>
FIG. 13 is a diagram for explaining a warning display performed by the center device when the reception level of the second-stage slave unit matches the threshold value condition continuously for a predetermined period of time. Here, FIG. 13A shows a transmission / reception level table 12112 when the slave unit 3-1b in the terminal communication status table 1211 for the slave unit 3-2 held by the center device 1 is a communication partner terminal, and FIG. 13B shows a transmission / reception level table 12112. The warning display 142 performed by the center device 1 is shown.

As shown in FIG. 13A, in the transmission / reception level table 12112, the reception level became 3 on February 10, 2017, and the threshold condition was met, so that the transmission / reception level table was continuously monitored. The threshold condition is also met at the time of the next communication (February 15, 2017, 5 days later), and the threshold condition is also met at the time of the next communication (February 27, 2017, 17 days later). That is, the reception level of the slave unit 3-2 matches the threshold condition continuously for a predetermined period after being the target of continuous monitoring.

Therefore, the display unit 14 of the center device 1 displays the warning display 142 shown in FIG. 13B, that is, at 17:00 on February 27, 2017, which is the final communication time, the handset 3-2, which is a poor communication terminal, and the communication partner. A warning display is performed in a mode in which the slave unit 3-1b, which is a terminal, and the reception level threshold value, which is a cause of communication failure, are included as display contents.

<< Threshold monitoring and warning display of transmission / reception level difference >>
FIG. 14 is a diagram for explaining a warning display performed by the center device when the state in which the transmission / reception level difference of the second-stage slave unit matches the threshold value condition is continuous for a predetermined period. Here, FIG. 14A shows a transmission / reception level table 12113 when the slave unit 3-1c in the terminal communication status table 1211 for the slave unit 3-2 held by the center device 1 is a communication partner terminal, and FIG. 14B shows a center. The warning display 143 performed by the device 1 is shown.

As shown in FIG. 14A, in the transmission / reception level table 12113, the transmission / reception level difference was 6 on March 10, 2017, which matched the threshold condition, and thus the subject was continuously monitored. The threshold condition is also met at the time of the next communication (March 15, 2017, 5 days later), and the threshold condition is also met at the time of the next communication (March 28, 2017, 18 days later). That is, the transmission / reception level difference of the slave unit 3-2 matches the threshold condition continuously for a predetermined period after being subject to continuous monitoring.

Therefore, the display unit 14 of the center device 1 displays the warning display 143 shown in FIG. 14B, that is, at 18:00 on March 28, 2017, which is the final communication time, the handset 3-2, which is a poor communication terminal, and the communication partner. A warning display is performed in a mode in which the slave unit 3-1c, which is a terminal, and the transmission / reception level difference threshold value or higher, which is a cause of communication failure, are included as display contents.

<< Threshold monitoring and warning display for the number of times the same message is retransmitted >>
FIG. 15 is a diagram for explaining a warning display performed by the center device when the state in which the same telegram retransmission count of the second-stage slave unit matches the threshold value condition is continuous for a predetermined period. Here, FIG. 15A shows the same telegram retransmission count table 12114 in the terminal communication status table 1211 for the slave unit 3-2 held by the center device 1, and FIG. 15B shows the warning display 144 performed by the center device 1.

As shown in FIG. 15A, in the same telegram retransmission count table 12114, the same telegram retransmission count was 5 times on April 10, 2017, which matched the threshold condition and was therefore subject to continuous monitoring. The threshold condition is also met at the time of the next communication (April 15, 2017, 5 days later), and the threshold condition is also met at the time of the next communication (April 29, 2017, 19 days later). That is, the number of times the same telegram is retransmitted by the slave unit 3-2 matches the threshold condition continuously for a predetermined period after being subject to continuous monitoring.

Therefore, the display unit 14 of the center device 1 displays the warning display 144 shown in FIG. 15B, that is, at 19:00 on April 29, 2017, which is the final communication time, the handset 3-2, which is a poor communication terminal, and the communication partner. A warning display is performed in which the display contents include the slave units 3-1a, 3-1b, 3-1c, which are terminals, and the retransmission count threshold value or more, which is a cause of communication failure.

<Procedure for reporting the meter reading value of the second-stage slave unit, the telegram transmitted in that procedure, and the information held in the terminal communication status table of the center device>
FIG. 16 shows the procedure when the second-stage slave unit reports the meter reading value and can receive the meter reading value acquisition completion notification from the center device, and the case where the retransmission is abandoned due to poor communication with the first-stage slave unit. It is a figure which shows the example of the procedure of.

The slave unit 3-2 transmits a meter reading value notification telegram to the slave unit 3-1a in order to notify the meter reading value to the center device 1 via the slave unit 3-1a (procedure S301). FIG. 17 shows the contents of the communication status table 3211 of the slave unit 3-2 and the contents of the meter reading value report telegram. As shown in the figure, the reception level in the communication status table 3211 is added to the meter reading value notification telegram 42 as the previous reception level. In addition, the number of times the same message is retransmitted is also added.

The slave unit 3-1a receives the meter reading value notification telegram from the slave unit 3-2, temporarily holds the reception level, that is, the transmission level of the slave unit 3-2 (10 in this case), and the slave unit 3 An ACK message is transmitted to -2 (procedure S302). The slave unit 3-2 receives the ACK message and stores (overwrites) the reception level (7 in this case) in the communication status table 3211. The communication status table 3211 updated by this storage is shown in FIG.

The slave unit 3-1a transmits a meter reading value notification telegram to the master unit 2 in order to notify the center device 1 of the meter reading value of the slave unit 3-2 via the master unit 2 (procedure S303). FIG. 19 shows the contents of the communication status table 3212 of the slave unit 3-1a and the contents of the meter reading value report telegram. As shown in the figure, the meter reading value reporting telegram 43 sets the reception level in the communication status table 321 (reception level of radio waves from the master unit 2 = 9) to the previous slave unit 3-1a with respect to the meter reading value reporting telegram 42. The transmission level (10 in this case) of the handset 3-2, which is acquired at the time of receiving the meter reading value notification telegram 42 (procedure S301) and temporarily held, is added as the reception level of the handset 3-2. It is added as the transmission level of.

The master unit 2 receives the meter reading value notification telegram from the slave unit 3-1a, temporarily holds the reception level, that is, the transmission level (here, 10) of the slave unit 3-1a, and the slave unit 3-1a. ACK message is transmitted to (Procedure S304). The slave unit 3-1a receives the ACK message and stores (overwrites) the reception level (here, 6) in the communication status table 3212. The communication status table 3211 updated by this storage is shown in FIG. 20A.

The master unit 2 transmits a meter reading value notification telegram including the meter reading value of the slave unit 3-2 to the center device 1 via the public communication line NW (procedure S305). The content of the meter reading value report telegram is shown in FIG. 20B. As shown in the figure, the meter reading value reporting message 44 is acquired when the reception level of the master unit 2 is carrier communication with respect to the meter reading value reporting message 43 and when the meter reading value reporting message 43 is received (procedure S303). , The transmission level of the slave unit 3-1a (10 in this case) temporarily held is added as the transmission level of the slave unit 3-1a.

The center device 1 receives the meter reading value report telegram 44 from the master unit 2, and includes the transmission level and reception level of the slave unit 3-2, the transmission level and reception level of the slave unit 3-1a, and the child. The same telegram retransmission count of the machine 3-2 is stored in the terminal communication status table 1211.

FIG. 21 shows the contents of the terminal communication status table 1211 holding the information stored at this time. Here, FIG. 21A is a transmission / reception level table 12111 and the same message retransmission count table 12114 when the slave unit 3-1a in the terminal communication status table 1211 for the slave unit 3-2 is a communication partner terminal, and FIG. 21B shows. The transmission / reception level table 12121 when the master unit 2 in the terminal communication status table 1212 for the slave unit 3-1a is the communication partner terminal.

Since the center device 1 transmits a meter reading value report completion notification telegram to the slave unit 3-2 via the communication route of the master unit 2 → the slave unit 3-1a → the slave unit 3-2, the center device 1 reads the meter to the master unit 2. A value completion notification message is transmitted (procedure S306). This meter reading value completion notification message is transmitted to the slave unit 3-2 via the master unit 2 and the slave unit 3-1a (procedures S307 and S308). When the slave unit 3-2 receives the meter reading value completion notification message, as shown in FIG. 22A, the slave unit 3-2 clears the same message retransmission count in the communication status table 3211 to 0.

However, if the slave unit 3-2 could not receive the meter reading value completion notification message, the slave unit 3-2 also failed to resend the fifth time, so the resend was abandoned and as shown in FIG. 22B. In addition, the number of times the same message is resent is set to FF. Then, by setting the number of times of retransmitting the same message in the meter reading value notification message to be transmitted at the next communication to FF, the center device 1 can recognize that the notification of the meter reading value this time has been abandoned. When the center device 1 receives this telegram, the center device 1 sets the slave unit 3-2 as a continuous monitoring target.

The procedure shown in FIG. 16 is a procedure when the slave unit 3-1a is a relay slave unit, but the same procedure is performed when the other first-stage slave unit is a relay slave unit.

<Notification of meter reading value of the second stage slave unit in response to the request from the center device>
FIG. 23 shows a procedure when the center device can acquire the meter reading value by retransmitting the second meter reading value request when the second-stage slave unit notifies the meter reading value in response to the request from the center device, and the center device. It is a figure which shows the number of times of continuous failure of telegram transmission in the communication status table of.

The center device 1 transmits a meter reading value request message to the slave unit 3-2, which is the slave unit for which the meter reading value is to be acquired, via the communication route of the master unit 2 → the slave unit 3-1a → the slave unit 3-2 ( Procedures S401 to S403). However, the slave unit 3-1a could not communicate with the slave unit 3-2, and an error notification message was transmitted to the center device 1 by the communication route of the slave unit 3-1a → the master unit 2 → the center device 1 (procedure S403, S404).

Therefore, the center device 1 sets the first failure date and time and the last failure date and time of the center-induced telegram transmission continuous failure count table 12115 in the terminal communication status table 1211 for the handset 3-2 held at 12:00 on April 1, 2017. 0 minutes was stored as 1 as the number of consecutive failures of telegram transmission caused by the center. Here, 12:00 on April 1, 2017 is the arrival time of the error notification.

Next, the center device 1 transmits a meter reading value request message to the slave unit 3-2 by the communication route of the master unit 2 → the slave unit 3-1a → the slave unit 3-2 as in the previous time (procedures S411 to S411). S413). Although the slave unit 3-2 transmitted the meter reading value response telegram, the center device 1 could not receive the meter reading value response telegram (procedures S414 to S416).

Therefore, the center device 1 updates (overwrites) the last failure date and time and the number of failures in the center-induced telegram transmission continuous failure number table 12115 in the terminal communication status table 1211 for the handset 3-2 held. Here, 13:00 on April 10, 2017, which is the final failure date and time, is the time-out time for the meter reading value request.

Next, the center device 1 transmits a meter reading value request message to the slave unit 3-2 by the communication route of the master unit 2 → the slave unit 3-1a → the slave unit 3-2 as in the previous time (procedures S421 to 1). S423). This time, the meter reading value response telegram was transmitted to the center device 1 (procedures S424 to S426).

Therefore, the center device 1 erases the first failure date and time and the last failure date and time of the center-induced telegram transmission continuous failure count table 12115 in the terminal communication status table 1211 for the handset 3-2 held, and sets the failure count to 0. It was reset by clearing it.

<Threshold monitoring and warning display of the number of consecutive telegram transmission failures caused by the center>
The center device 1 monitors the number of consecutive failures of telegram transmission caused by the center in the terminal communication status table 1211 for the handset 3-2 held by the center device 1 and transmits the telegram transmission even once. If it fails, the slave unit to which the telegram is sent is continuously monitored. That is, the threshold condition for whether or not to be continuously monitored is set to once.

Then, when telegram transmission fails continuously for a predetermined period (the number of days or the number of times; 15 days or more in this embodiment) to the slave unit subject to continuous monitoring, the display unit 14 of the center device 1 displays. Display a warning. Even if it becomes a continuous monitoring target, if the threshold condition is not met at the next communication, the warning is not displayed and it is excluded from the continuous monitoring target.

FIG. 24 is a diagram for explaining a warning display performed by the center device when the number of consecutive failures of telegram transmission caused by the center matches the threshold value condition for a predetermined period of time. Here, FIG. 24A shows a center-induced telegram transmission continuous failure count table 12115 when the state in which the center-induced telegram transmission continuous failure count matches the threshold value condition is continuous for a predetermined period, and FIG. 24B shows the table 12115. The warning display 145 performed by the center device 1 in this case is shown.

As shown in FIG. 24A, the number of consecutive failures of telegram transmission caused by the center has reached 10 times, and the telegram transmission has failed for 19 days. Therefore, the display unit 14 of the center device 1 displays the warning display 145 shown in FIG. 24B, that is, the final failure time, the handset 3-2 which is a communication failure terminal, the handset 3-1a which is a communication partner terminal, and A warning is displayed that includes the number of consecutive failures of telegram transmission caused by the center, which is the cause of communication failure, as the display content.

<Procedure for requesting the meter reading value from the center device for the second-stage slave unit and responding to the meter reading value according to the procedure, the telegram transmitted in that procedure, and the information held in the table of the slave unit and the center device>

FIG. 25 is a diagram showing a procedure in which the second-stage slave unit reports the meter reading value in response to a request from the center device.

Since the center device 1 transmits a meter reading value request message to the slave unit 3-2 by the incoming route of the master unit 2 → the slave unit 3-1a → the slave unit 3-2, the center device 1 transmits the meter reading value request message to the master unit 2. (Procedure S501). The meter reading value request telegram 51 transmitted at this time is shown in FIG. 26A. When the master unit 2 receives the meter reading value request message 51, the master unit 2 transmits the meter reading value request message to the slave unit 3-1a (procedure S502). The meter reading request message transmitted at this time is shown in FIG. 26B. The content of the meter reading value requesting telegram 52 is the same as the content of the meter reading value requesting telegram 51.

The slave unit 3-1a receives the meter reading value request message 52 from the master unit 2 and at the same time acquires the reception level (9 in this case) of the message and receives the communication partner (master unit 2) in the communication status table 3212. Update level to 9. The communication status table 3212 holding the updated reception level is shown in FIG. 27A.

The slave unit 3-1a transmits an ACK telegram to the master unit 2 (procedure S503). When the master unit 2 receives this ACK message, it temporarily holds the reception level, that is, the transmission level (here, 10) of the slave unit 3-1a.

The slave unit 3-1a transmits a meter reading value request telegram to the slave unit 3-2 (procedure S504). The content of the meter reading value request telegram transmitted at this time is shown in FIG. 27B. The content of the meter reading value requesting telegram 53 is the same as the content of the meter reading value requesting telegrams 51 and 52.

The slave unit 3-2 receives the meter reading value request message 53, simultaneously acquires the reception level of the message, and updates the reception level of the slave unit 3-1a in the communication status table 3211. The communication status table 3211 holding the updated reception level is shown in FIG. 28A.

The slave unit 3-2 transmits an ACK telegram to the slave unit 3-1a (procedure S505). The slave unit 3-1a receives the ACK message, acquires the reception level thereof, that is, the transmission level of the slave unit 3-2 (10 in this case), and temporarily holds the reception level.

The slave unit 3-2 transmits a meter reading value response telegram to the slave unit 3-1a in order to notify the center device 1 of the meter reading value acquisition result via the slave unit 3-1a (procedure S506). The content of this meter reading value response telegram is shown in FIG. 28B. As shown in the figure, the reception level (10 in this case) acquired from the meter reading request message 53 received in the procedure S504 is added to the meter reading value response message 54.

The slave unit 3-1a receives the meter reading value response message 54, acquires the reception level thereof, that is, the transmission level of the slave unit 3-2 (10 in this case), and temporarily holds the reception level. As a result, the transmission level of the slave unit 3-2 acquired from the ACK message received in step S505 is updated (overwritten).

The slave unit 3-1a transmits an ACK telegram to the slave unit 3-2 (procedure S507). The slave unit 3-2 receives the ACK message, acquires the reception level (7 in this case), and updates the reception level of the slave unit 3-1a in the communication status table 3211. The communication status table 3211 holding the updated reception level is shown in FIG. 29A.

The slave unit 3-1a transmits a meter reading value response telegram to the master unit 2 in order to notify the center device 1 of the meter reading value of the slave unit 3-2 via the master unit 2 (procedure S508). The meter reading value response telegram 55 transmitted at this time is shown in FIG. 29B. As shown in the figure, the meter reading value response message 55 adds the reception level (= 9) of the meter reading value request message 52 received in the procedure S502 as the reception level of the slave unit 3-1a to the meter reading value response message 54. , The transmission level (= 10) of the meter reading value response telegram 54 received in the procedure S506 is added as the current transmission level of the slave unit 3-2.

When the master unit 2 receives the meter reading value response message 55 from the slave unit 3-1a, the master unit 2 acquires the reception level of the message, that is, the transmission level of the slave unit 3-1a (10 in this case), and temporarily holds the message. .. As a result, the transmission level of the slave unit 3-1a acquired from the ACK message received in step S503 is updated (overwritten).

The master unit 2 transmits an ACK telegram to the slave unit 3-1a (procedure S509). The slave unit 3-1a receives the ACK message, acquires the reception level (5 in this case), and updates the reception level of the communication partner (master unit 2) in the communication status table 3212. The communication status table 3212 holding the updated reception level is shown in FIG. 30A.

The master unit 2 transmits a meter reading value response telegram to the center device 1 (procedure S510). The meter reading value response telegram transmitted at this time is shown in FIG. 30B. As shown in the figure, the content of the meter reading value response message 56 is that the transmission level (= 10) of the meter reading value response message 55 received in step S508 is transmitted to the meter reading value response message 54 this time by the slave unit 3-1a. It is added as a level, and carrier communication is added as a reception level of the master unit 2.

The center device 1 receives the meter reading value response telegram 56, and stores the reception time (arrival time) of the telegram and the transmission level and reception level included in the telegram in the terminal communication status table 121. FIG. 31 shows a terminal communication status table 121 in which these transmission levels and reception levels are stored. Here, FIG. 31A shows a transmission / reception level table 12111 when the slave unit 3-1a in the terminal communication status table 1211 for the slave unit 3-2 is a communication partner terminal, and FIG. 31B shows a terminal for the slave unit 3-1a. The transmission / reception level table 12121 when the master unit 2 in the communication status table 1212 is the communication partner terminal is shown.

The procedure shown in FIG. 25 is a procedure when the slave unit 3-1a is a relay slave unit, but the same procedure is performed when the other first-stage slave unit is a relay slave unit.

As described in detail above, according to the remote monitoring system according to the embodiment of the present invention, the following effects (1) to (5) can be obtained.
(1) The center device 1 monitors the transmission / reception level of the slave unit 3 and the number of times the same telegram is retransmitted for a predetermined period of time, so that the slave unit with poor communication can be detected while avoiding a temporary failure such as an environmental factor.
(2) When the slave unit 3 abandons the retransmission of the same telegram, the number of retransmissions is set to a specific value (for example, FF) at the time of the next notification, so that the center device can know that the abandonment has been given. Also, by adding the date and time when the retransmission was abandoned, it is possible to know when the communication failure occurred.
(3) Check the communication status of the upper terminal managed by the center device 1, and if communication failure with some terminals is found, it is possible to suspect the specific terminal and the communication environment with the specific terminal, and with many terminals. When communication failure is seen, it is possible to suspect the own terminal and the environment around the own terminal.
(4) Even when the center device 1 acquires or controls the meter reading value of the slave unit 3, the slave unit 3 (including the relay slave unit) memorizes the transmission / reception level and notifies the meter reading value acquisition result telegram. And control result notification The transmission / reception level can be notified to the center device 1 by adding it to a telegram or the like.
(5) Even when the center device 1 transmits a telegram to the slave unit 3, the center device 1 has a table for storing the number of consecutive failures of the telegram transmission caused by the center, so that the slave unit can be monitored from the center viewpoint. It will be possible.

In the embodiment described above, three types of information including the reception level, the transmission level, and the same number of times the telegram is retransmitted are used as the communication status information, but any one or two of these may be used. Further, the embodiment described above is for reporting the meter reading value as monitoring information, but the present invention can be similarly applied to the case of reporting a gas leak alarm or a low battery level alarm as monitoring information. ..

1 ... Center device, 2 ... Master unit, 3 ... Slave unit, 121 ... Terminal communication status table, 122 ... Monitoring threshold table, 321 ... Communication status table.

Claims (2)

A remote monitoring system that has a center device, a master unit that is a wireless terminal, and a plurality of slave units that have a multi-stage configuration, and each slave unit transmits the acquired monitoring information to the center device via a higher-level wireless terminal. There,
The center device acquires communication status information indicating the communication status with the wireless terminal directly above each slave unit added to the monitoring information notification telegram transmitted from each slave unit via the master unit. Then, it is determined that the slave unit in which the value of the communication status information matches the predetermined threshold value for a predetermined period of time has caused a communication failure.
The communication status information includes the same number of times the telegram is retransmitted, and each slave unit abandons this report because the number of times the same telegram retransmitted added to the monitoring information report message transmitted at the time of this report matches the predetermined threshold condition. In this case, a remote monitoring system in which the number of times the same message is retransmitted added to the monitoring information report message to be sent at the next report is set to a specific value indicating that the report has been abandoned this time. In the remote monitoring system according to claim 1,
Wherein the communication status information, reception levels of the same message retransmission number or the transmission level and the same message number of retransmissions or remote monitoring system and the reception level is the transmission level and the same message number of retransmissions,.

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