JP6481514B2 - Communication apparatus and communication system - Google Patents

Description

  The present invention relates to, for example, a remote meter reading system that automatically performs meter reading of a gas meter or a water meter, and a communication device and a communication system used in a remote monitoring system such as a fire or abnormal situation monitoring.

  There is known a remote meter reading system that includes a center device, a parent device, and a plurality of child devices, and the plurality of child devices are configured in multiple stages (Patent Document 1). In this system, each slave unit transmits meter reading data to the center device via the master unit, and a multi-stage configuration makes it possible to collect a large amount of meter reading data.

  In such a remote meter-reading system, each slave unit has a function of registering and holding a plurality of communication paths from the own terminal to the master unit. For example, when the first path is incapable of communication, the second path By switching to the third path, the communication quality of the entire system is ensured.

  Registration of the communication path of the slave unit in such a remote meter reading system is performed as follows, for example. When a child device is newly installed, the child device first transmits (broadcasts) a test signal in which the terminal ID (identification information) of the own terminal is added to the broadcast message, and within a predetermined time, other terminals (parent device, Check whether there is a response from the slave unit.

  If there is a response within a predetermined time, select a terminal with good communication conditions from the terminal ID, electric field strength, and number of relay stages included in the response message, and finally select one or more communication paths, that is, communication partners Information related to one or more immediately higher-level terminals (terminal ID, electric field strength) and the number of relay stages (number of stages from the parent device) of each terminal in each communication path are registered in the storage unit of the terminal. Here, the number of relay stages of the own terminal is calculated by adding 1 to the number of relay stages of the immediately higher terminal.

  Also, route numbers such as the first route and the second route are assigned in order of increasing electric field strength from the electric field strength and the number of relay steps acquired at the time of registration. Then, a message for requesting registration of these communication paths (this message includes the terminal ID of the new handset, the terminal ID and electric field strength of the communication partner, and the number of relay stages of the new handset) is transmitted to the center device. The center device registers the route.

  In such a remote meter reading system, it is also known that the slave unit newly searches for a communication path to the master unit when all the communication paths held by the slave unit are not communicable. At this time, the slave unit stores the terminal ID of the direct host terminal that is the communication partner on the new communication path and the relay stage number of the own terminal on the new communication path in the storage unit of the own terminal.

  Also, in such a remote meter reading system, as a system limitation, when the master unit collects meter reading data from the terminal unit at the end, there is a waiting time from the time when the meter reading data request is transmitted until the time when the meter reading data is received. There is a limit, and the maximum number of relay stages (for example, three stages) for satisfying the limit is determined.

  Since the conventional remote meter-reading system is configured as described above, the number of relay stages of the slave unit that newly searches for the communication route to the master unit and registers the new communication route may change. In this case, the number of relay stages of the slave units under the slave unit, that is, the slave units having the slave unit as a relay slave unit also changes.

  That is, for example, a slave unit at the first stage, that is, a slave unit directly below the master unit (hereinafter referred to as the first slave unit) has a communication error with the master unit, so that the other slave unit at the first stage When a route for communicating with the parent device via the second child device (hereinafter referred to as the second child device) is a new communication route, the number of relay stages of the first child device increases from the first to the second step. For this reason, the number of relay stages of the slave unit immediately below the first slave unit (hereinafter referred to as the third slave unit) is also increased by one to the third level. If there is a slave unit directly below the third slave unit, The number of stages is also increased by one.

  However, since the third handset holds information indicating that it is the second stage regardless of the relay stage number of its own terminal being changed to the third stage, when the maximum number of relay stages is three, that is, If the slave unit with the third relay stage number cannot be a relay slave unit of another slave unit, the following problem occurs.

  That is, when a new slave unit is installed (added), the new slave unit has the second relay stage included in the response message from the third slave unit with respect to the test signal. Is registered as a communication partner (direct terminal).

  The center device solves the above problem by transmitting a communication path re-search instruction to the third slave unit and its slave units, that is, all slave units subordinate to the first slave unit. It is possible. However, at this time, since instructions for the number of slave units subordinate to the first slave unit are transmitted from the center device and delivered to each slave unit, there are particularly many slave units subordinate to the first slave unit. The communication line is occupied and traffic is congested. Further, resources (CPU, memory, etc.) of the center device are also occupied.

JP 2010-87761 A

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a communication system having a center device, a parent device, and a plurality of child devices having a multi-stage configuration, in which the number of relay stages of the child devices is When changing, it is possible to execute the change of the number of relay stages of the subordinate slaves without occupying the resources of the communication line and the center device.

  The present invention is a communication device used as the slave unit in a communication system having a center device, a master unit, and a plurality of slave units having a multi-stage configuration, a route search unit that performs route search, and the route search As a result, when the number of relay stages of the terminal changes, the communication apparatus has a relay stage number notification unit that notifies the subordinate slave unit of the number of relay stages after the change.

  According to the present invention, in a communication system having a center device, a master unit, and a plurality of slave units having a multi-stage configuration, when the relay stage number of the slave unit changes, the change of the relay stage number of the subordinate slave unit is changed. It can be executed without occupying the resources of the communication line and the center device.

It is a figure which shows the structure of the communication system which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of the subunit | mobile_unit in the communication system which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of the main | base station in the communication system which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of the center apparatus in the communication system which concerns on embodiment of this invention. It is a figure which shows the state which the communication error generate | occur | produced between the 1st step | paragraph subunit | mobile_unit and the main | base station in the communication system which concerns on embodiment of this invention. It is a sequence diagram which shows operation | movement when the communication system which concerns on embodiment of this invention will be in the state shown in FIG. It is a flowchart which shows the content of the relay stage number change process in FIG. It is a figure which shows the communication path and the number of relay stages after the communication system which concerns on embodiment of this invention performs the operation | movement shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of communication system>
FIG. 1 is a diagram showing a configuration of a communication system according to an embodiment of the present invention.
This communication system is used in, for example, an automatic meter reading system for gas and water meters, and is a plurality of (seven in this case) wireless terminals as communication devices provided in each meter reading device (meter, etc.). It consists of the subunit | mobile_unit 40a-40g and the main | base station 30 which receives the meter-reading data from the subunit | mobile_unit 40a-40g while managing the subunit | mobile_unit 40a-40g. In the present embodiment, the base unit 30 is further connected to the center apparatus 10 via a public communication line 20 such as a mobile phone line. In addition, in the following description, it is set as the subunit | mobile_unit 40 when not distinguishing subunit | mobile_unit 40a-40g.

  The parent device 30 can communicate with the child device 40 by wireless communication such as specific low-power radio, and the child devices 40 can also communicate with each other by wireless communication such as specific low-power wireless. Moreover, the subunit | mobile_unit 40 has transmitted meter-reading data to the center apparatus 10 via the main | base station 30, and enables collection of more meter-reading data by setting it as a multistage structure (here 3 steps | paragraphs).

  In the present embodiment, the slave units 40 a and 40 b are connected to the first stage of the number of relay stages, that is, directly below the master unit 30. Further, in the second stage of the number of relay stages, the slave unit 40c is connected directly below the slave unit 40a, and the slave units 40d and 40e are connected directly below the slave unit 40b. Further, in the third stage of the number of relay stages, the slave unit 40f is connected directly below the slave unit 40c, and the slave unit 40g is connected directly below the slave units 40d and 40e.

  That is, seven slave devices 40a to 40g are connected in a three-stage configuration under the master device 30, and slave devices 40c and 40f are connected in a two-tier configuration under the first slave device 40a, and the first slave device 40b. Are connected to the slave units 40d, 40e, and 40g in a two-stage configuration. In addition, a slave unit 40f is connected in a one-stage configuration under the second-stage slave unit 40c, a slave unit 40g is connected in a one-stage configuration under the second-stage slave unit 40d, and one stage is connected under the second-stage slave unit 40e. The subunit | mobile_unit 40g is connected by the structure. The third-stage child device 40g holds two communication paths (40g-40d, 40g-40e).

<Configuration of slave unit>
FIG. 2 is a block diagram showing a schematic configuration of the slave unit 40 in FIG.
As illustrated, the slave unit 40 (40a to 40g) includes a control unit 41, a transmission / reception unit 42, a storage unit 43, an I / F (interface) unit 44, a display unit 45, which are connected to the control unit 41, And an operation input unit 46, and an antenna 47 is connected to the transmission / reception unit 42.

  The control unit 41 includes a CPU, a RAM, and a ROM, and performs overall control of the slave unit 40, arithmetic processing, and the like. The transmission / reception unit 42 performs wireless communication with other child devices 40 and the parent device 30 by short-range wireless communication. The memory | storage part 43 consists of non-volatile memories, and memorize | stores various setting data. External devices such as meters such as gas and water are connected to the I / F unit 44. The display unit 45 is configured by an LED or the like, and is a user I / F that displays an operation state or the like of the slave unit 40. The operation input unit 46 includes a button, a switch, and the like, and is a user I / F for inputting predetermined settings for the child device 40. The antenna 47 transmits and receives radio waves.

  The control unit 41 reads the program stored in the ROM by the built-in CPU into the RAM, and processes the RAM as a work area. As a functional block, the route search unit 41a, the route information acquisition unit 41b, and message analysis A unit 41c, a relay stage number notification unit 41d, and a relay stage number change processing unit 41e.

  The route search unit 41a generates a test signal in which the terminal ID (identification information) of its own terminal is added to the broadcast message, and determines the parent device 30 or the child device 40 that can communicate from the response message. The route information acquisition unit 41 b stores the route information (terminal ID, electric field strength, number of relay stages) for the parent device 30 or the child device 40 determined by the route search unit 41 a in the storage unit 43. The message analysis unit 41 c analyzes a message transmitted from another child device 40.

  When the relay stage number in the route information acquired by the route information acquisition unit 41b changes, the relay stage number notification unit 41d reports the changed relay stage number in accordance with the relay stage number change instruction from the center device 10 and the slave unit 40 Notify When the relay stage number change processing unit 41e receives the relay stage number transmitted from the terminal immediately above, it changes the relay stage number of its own terminal to the received relay stage number + 1.

<Main unit configuration>
FIG. 3 is a block diagram showing a schematic configuration of base unit 30 in FIG.
The base unit 30 includes a control unit 31, a storage unit 32, a transmission / reception unit 33, a network control unit 34, a display unit 35, and an operation input unit 36 each connected to the control unit 31.

  The control unit 31 includes a CPU, a RAM, and a ROM, and performs overall control of the parent device 30 and arithmetic processing. The storage unit 32 includes a non-volatile memory, and stores data necessary for control by the control unit 31 and arithmetic processing. The transmission / reception unit 33 performs wireless communication with the child device 40 by short-range wireless communication. The network control unit 34 communicates with the center apparatus 10 via a public communication line. The display unit 35 is configured by an LED or the like, and displays an operation state or the like of the parent device 30. The operation input unit 36 includes a button, a switch, and the like, and is a user I / F for inputting predetermined settings for the parent device 30. The antenna 37 transmits and receives radio waves.

<Configuration of center device>
FIG. 4 is a block diagram showing a schematic configuration of the center apparatus 10 in FIG.
The center device 10 includes a control unit 11, a network control unit 12, a storage unit 13, a display unit 14, and an operation input unit 15, each connected to the control unit 11.

  The control unit 11 includes a CPU, a RAM, and a ROM, and performs control of the entire center device 10 and arithmetic processing. In this embodiment, the CPU includes an update registration unit 11a and a relay stage number change instruction unit 11b as functional blocks realized by reading a program stored in the ROM into the RAM and processing the RAM as a work area.

  The update registration unit 11a performs registration processing of the terminal IDs of the parent device 30 and the child device 40, and newly registers the route information in the storage unit 13 based on the route information transmitted from the child device 40 side. Register for update. When the relay stage number of the slave unit 40 that has performed the reroute search changes, the relay stage number change instruction unit 11b notifies the slave unit 40 of the relay stage number change instruction.

  The storage unit 13 includes, for example, a non-volatile memory, a hard disk drive, and the like, and includes a management data table including the terminal ID of each registered child device 40 and information on external devices connected to each child device 40, and the like. In addition to information related to a system necessary for communication such as a terminal ID, data of an external device transmitted from the parent device 30 is stored.

  The display unit 14 is, for example, a liquid crystal display (LCD), and displays information related to the system, information related to external devices connected to the child device 40, an operation screen at the time of input to the center device 10, and the like. The operation input unit 15 includes input means such as a keyboard and a mouse for inputting various data and commands to the center device 10 from the outside.

<Operation from occurrence of communication error to registration of new route and change of number of relay stages>
FIG. 5 is a diagram illustrating a state in which a communication error has occurred between the first-stage child device 40a and the parent device 30 in FIG. Since the slave unit 40a has one communication path with the master unit 30, the slave unit 40a performs a re-route search when it enters this state.

  6 is a sequence diagram showing an operation when the communication system according to the embodiment of the present invention enters the state shown in FIG. 5, and FIG. 7 is a flowchart showing the contents of the relay stage number changing process in FIG. . Hereinafter, with reference to these drawings, the reroute search of the child device 40a, the subsequent communication route, and the number of relay stages of each child device will be described.

  As shown in FIG. 6, when a communication error occurs between the slave unit 40a and the master unit 30, the slave unit 40a performs a reroute search (step S1). That is, a test signal in which the terminal ID of its own terminal is added to the broadcast message is transmitted (broadcast), and it is checked whether there is a response from another terminal (parent device or child device) within a predetermined time.

  Next, the subunit | mobile_unit 40a receives a response message from a surrounding terminal, and acquires terminal ID, the number of relay steps, and electric field strength (step S2). Here, it is assumed that a response message has been received from the slave units 40b, 40c, and 40d. The number of relay stages of the slave units 40b, 40c, and 40d is the first stage, the second stage, and the second stage from FIGS. 1 and 5, respectively.

  Next, the subunit | mobile_unit 40a determines a new communication path | route (step S3). In this embodiment, when there is a response within a predetermined time, the slave unit 40a selects a terminal with good communication conditions from the terminal ID, the electric field strength, and the number of relay stages included in the response message. Then, the route information acquisition unit 41b finally sets one communication route as a new communication route. Here, it is assumed that among the slave units 40b, 40c, and 40d, the slave unit 40b having the smallest number of relay stages is determined as the communication partner (direct upper terminal) of the new communication path.

  Next, the route information acquisition unit 41b automatically obtains information on the determined communication route, that is, information related to the directly upper terminal serving as a communication partner (terminal ID, electric field strength) and the number of relay stages (the number of steps from the base unit 30) of the terminal in the route. Store in the storage unit 43 of the terminal (step S4). Here, since the number of relay stages of the own terminal is the number of relay stages of the communication partner + 1, it changes from the first stage before the occurrence of the communication error to the second stage.

  Next, handset 40a transmits a new route registration request message to center device 10 using the new route (step S5). This electronic message includes the terminal ID and the number of relay stages of the slave unit 40a, the terminal ID of the slave unit 40b that is the communication partner, and the electric field strength.

  The center device 10 that has received the new route registration request message from the child device 40a determines whether or not the number of relay stages of the child device 40a that is the new route registration request terminal has changed (step S6). Here, whether or not the number of relay stages has changed is determined by a message for requesting registration of the relay stage number of the slave unit 40a and the new path in the old path (path before the occurrence of the communication error) stored in the storage unit 13 of the center apparatus 10. Determination is made by comparing the number of relay stages of the slave unit 40a.

  In the present embodiment, the number of relay stages of the slave unit 40a is the first stage in the old route and the second stage in the new route, so the number of relay stages is changed. Therefore, the center apparatus 10 determines that the number of relay stages of the slave unit 40a that is the terminal that has requested registration of the new route has changed (step S6: YES), and the new route related to the registration request to the slave unit 40a. Is used to transmit a relay stage number change instruction (step S7). When it is determined that the number of relay stages has not changed (step S6: NO), the process is terminated as it is.

  The subunit | mobile_unit 40a transmits the broadcast message | telegram containing the terminal ID of an own terminal, and the number of relay steps based on reception of the relay step number change instruction (step S8). Each terminal that receives this message performs a relay stage number change process (step S9 (S9a, S9b, S9c)). In the figure, the slave units 40b, 40c, and 40d perform the relay stage number change process. However, if the master unit 30 and the slave units 40e, 40f, and 40g also receive a message, the relay stage number change process is performed.

  As shown in FIG. 7, in the relay stage number changing process, it is determined whether or not the terminal ID in the received message (here, the terminal ID of the slave unit 40a) is the transmission destination ID of the own terminal. It is determined whether or not the terminal ID of the terminal directly above the terminal (step S91).

  As a result of the determination, if it is the transmission destination ID of the own terminal (step S91: YES), the number of relay stages of the own terminal stored in the storage unit 43 is added to the value obtained by adding 1 to the number of relay stages in the received message. Change (step S92). As a result of the determination, if it is not the transmission destination ID of the own terminal (step S91: NO), the process is terminated as it is. In the present embodiment, only the slave unit 40c located immediately below the slave unit 40a changes the number of relay stages.

  Returning to the description of FIG. Of the slave units 40b, 40c, and 40d that have undergone the relay stage number change process, the slave unit 40c that has changed the relay stage number of its own terminal notifies the center device 10 of this fact (step S10). The center device 10 changes the number of relay stages of the slave unit 40c stored in the storage unit 13.

<New communication path and number of relay stages for each slave unit>
FIG. 8 is a diagram showing a communication path and the number of relay stages after the communication system according to the embodiment of the present invention performs the operation shown in FIG.

  As shown in the figure, since the slave unit 40a is connected to the master unit 30 with the slave unit 40b as a relay slave unit, the number of relay stages of the slave unit 40a increases from the first level to the second level. Therefore, the number of relay stages of the slave unit 40c under the control increases from the second stage to the third stage.

  Note that the slave unit 40f is actually the fourth stage because it is located immediately below the slave unit 40c changed to the third stage, but the number of relay stages held is still the third stage. Then, it was set as the third stage.

  Therefore, when the maximum number of relayable relays is three, the slave unit 40f cannot communicate with the slave unit 40c, so that the route is searched again. At the time of this re-search, since the slave unit 40c responds to the test signal from the slave unit 40f as the third stage after the change of the relay stage number of its own terminal, the slave unit 40f makes the slave unit 40c a communication partner (directly connected). It does not select a route as a higher order terminal. The same applies to the case where a new slave unit is added.

As described above in detail, the communication system according to the embodiment of the present invention has the following features (1) to (2).
(1) The slave unit 40 that has performed the reroute search notifies the peripheral terminal of the changed number of relay stages when the number of relay stages of the terminal changes as a result of the reroute search. Without occupying the communication line between the terminals such as the center apparatus 10 and the parent machine 30, the number of relay stages of the child machines subordinate to the child machine that has performed the reroute search can be changed.
(2) The slave unit whose relay stage number has changed notifies the relay stage number at the same time by broadcast. Therefore, when multiple slave units are connected directly below, each slave unit is individually and individually unicasted. Compared to the case of notification, the communication line usage time until the stage number change is completed is shortened.

  Although the communication system according to the embodiment described above has a three-stage configuration, the present invention can also be applied to a communication system having a multi-stage configuration of two stages, four stages or more. In the case of four or more stages, the slave unit that has received the relay stage number change instruction from the center apparatus is configured to notify the slave unit directly below the relay stage number change instruction in addition to the relay stage number of its own terminal.

  That is, for example, in the case of FIG. 8, the slave unit 40a transmits a relay stage number change instruction to the slave unit 40c in addition to the ID of the own terminal and the relay stage number, and the slave unit 40c transmits its own instruction to the slave unit 40f. The number of relay stages after the terminal change is transmitted. By executing this procedure, the number of relay stages of the slave unit 40f can be changed to the fourth stage.

DESCRIPTION OF SYMBOLS 10 ... Center apparatus, 11a ... Update registration part, 11b ... Relay stage number change instruction | indication part, 30 ... Master unit, 40, 40a-40g ... Slave unit, 41a ... Path | route search part, 41b ... Path | route information acquisition part, 41c ... Message analysis 41d: Relay stage number notification unit, 41e: Relay stage number change processing unit.

Claims (4)

A communication device used as the slave unit in a communication system having a center device, a master unit, and a plurality of slave units having a multi-stage configuration,
A route search unit for performing a route search;
As a result of the route search, when the relay stage number of the terminal changes, the relay stage number notification unit that notifies the subordinate slave unit of the relay stage number after the change;
A communication device. The communication device according to claim 1,
The relay stage number notifying unit is a communication apparatus that notifies all the slave units under the relay stage number simultaneously. The communication device according to claim 1,
When the number of relay stages after the change is notified from another slave unit constituting the communication system, the identification information of the other slave unit that is notified together with the notification of the relay stage number is the identification of the communication partner of the own terminal A communication apparatus having a relay stage number change processing unit that changes the relay stage number of its own terminal to a value obtained by adding 1 to the notified relay stage number when it matches the information. A communication system having a center device, a parent device, and a plurality of child devices having a multi-stage configuration,
A communication system using the communication device according to claim 1 as the slave unit.

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