JP2011077720A - Radio communication network system and radio data communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of messages transmitted and received at the time of acquiring survival information of a relay device and a slave device in which a master device is connected with a low-order device in a radio communication network system having a tree structure. <P>SOLUTION: Each of a slave device 40 and a relay device 30 transmits a survival informing message for a master device 20 for each determined time instructed by a timer 14. The master device 20 performs reception check of the survival informing message transmitted for each of them for each predetermined time. If reception of the survival informing message is checked, it determines that a slave device 40 or relay device 30 that is a source origin for transmitting the survival informing message is active, but if reception of the survival informing message is not checked, it determines that the slave device 40 or relay device 30 that is a source for transmitting the survival informing message is not active, then stores survival or non-survival information of the slave device 40 and relay device 30, which is obtained by the determination, in a network construction information storing section 16 as low-level device survival information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless communication network system configured by connecting a plurality of wireless data communication devices in a tree shape, and a wireless data communication device used in the wireless communication network system.

  In a tree-structured multi-hop wireless communication network system, the top-level master unit in the tree structure is used for the maintenance and management of the network system. It is necessary to keep track of the communication line status at all times.

  In Patent Document 1, in a multi-hop wireless communication network system, a connection confirmation and connection response message is transmitted and received between a higher-level device and a lower-level device having a parent-child relationship, thereby detecting a failure in a transmission path between the two. In addition, a technique is disclosed in which when a failure is detected, failure recovery is performed by changing the connection of a higher-level device with respect to a lower-level device to another higher-level device.

  This failure recovery technique can be recognized as having great effects such as being possible without operator intervention, but is not applicable to any wireless communication network system. In other words, in order to apply this technique, the lower level device must always be able to communicate with at least two higher level devices. Therefore, for example, when a multi-hop wireless communication network is installed in a vast plant facility using a communicator whose communication distance is not so long (for example, about 10 m), the terminal communicator is particularly In many cases, it is difficult to secure two or more higher-level devices that can communicate with each other.

  In that case, a connection confirmation command such as ping that is conventionally used must be used. That is, the uppermost master unit acquires a response message by transmitting a connection confirmation message such as ping to each relay unit and the terminal unit at the end, and based on the acquired response message, the relay unit And the survival information of the slave unit and the communication line connection status information in the communication path from the master unit to the slave unit.

JP 2008-148032 A

  However, when the highest-level parent device transmits a connection confirmation command such as ping to each of the relay device and the child device, and obtains a response message from each relay device and the child device, the connection confirmation command and the response message Will go back and forth between the main unit and the repeater and sub unit. That is, in this case, the number of messages transmitted / received between the parent device, the relay device, and the child device increases, and the communication capacity of the communication line is reduced.

  In this case, since the parent device determines the timing of connection confirmation command transmission, the child device cannot determine the timing of transmitting the response message by itself. Therefore, in the slave unit, there may occur a case where the response message of the connection confirmation command and the timing of transmitting the plant facility monitoring data measured by the sensor or the like compete.

  Therefore, the present invention provides a message transmission / reception when a top-level wireless data communication apparatus (master unit) acquires survival information of a relay unit and a slave unit connected to a lower level in a tree-structured wireless communication network system. An object of the present invention is to reduce the number and avoid and adjust the transmission timing conflict between the survival information notification message and the monitoring data in the slave unit.

  The wireless communication network system according to the present invention is configured by connecting a parent device, a relay device, and a child device in a tree shape. Each slave unit and relay unit has a timer for instructing the transmission timing of the survival notification message, and transmits a survival notification message addressed to the parent unit each time the transmission timing is instructed by the timer. . On the other hand, the master unit performs reception confirmation of the survival notification message transmitted from each of the slave unit and the relay unit at predetermined time intervals, and if reception of the survival notification message is confirmed, transmits the survival notification message. If it is determined that the original slave unit or relay device is alive and reception of the survival notification message is not confirmed, it is determined that the slave unit or relay device that is the source of the survival notification message is not alive. The information on the survival or non-survival of the determined slave unit and relay unit is stored and managed in its own storage device.

  In the present invention, the master unit acquires information on whether the slave unit and the relay unit are alive or not based on whether or not the slave unit or the relay unit receives a survival notification message autonomously transmitted. In this case, since the master unit does not need to send a message requesting the transmission of the survival notification message to each of the slave unit and the relay unit, the number of messages transmitted and received in the network can be reduced. Can do. Further, in the present invention, since the timing at which the slave unit transmits the survival notification message can be determined, it is possible to avoid contention between the survival notification message transmission timing and the monitoring data transmission timing.

  According to the present invention, in a wireless communication network system having a tree structure, messages transmitted and received when the highest-level wireless data communication apparatus (master unit) acquires the survival information of relay units and slave units connected to lower layers. It is possible to reduce the number and avoid and adjust the transmission timing conflict between the survival information notification message and the monitoring data in the slave unit.

The figure which showed the example of the structure of the radio | wireless data communication apparatus which concerns on embodiment of this invention, and the radio | wireless communication network system comprised using the radio | wireless data communication apparatus. The figure which showed the example of the other structure of the radio | wireless communication network system which concerns on embodiment of this invention. The figure which showed the example of the structure of the network configuration information storage part in the radio | wireless data communication apparatus which concerns on embodiment of this invention. The figure which showed the example of a structure of the line state information storage part in the radio | wireless data communication apparatus which concerns on embodiment of this invention. The figure which showed the example of the structure of the survival notification frame and survival response frame used in the radio | wireless communication network system which concerns on embodiment of this invention. The figure which showed the example of a mode that the survival notification frame and the survival response frame were transmitted / received in the radio | wireless communication network system which concerns on embodiment of this invention. The figure which showed the example of the external appearance perspective view of the radio | wireless data communication apparatus which concerns on embodiment of this invention. The figure which showed the example of the lighting conditions of the display lamp of the radio | wireless data communication apparatus which concerns on embodiment of this invention. The figure which showed the example of the processing flow of the survival notification frame transmission / transfer process and survival response frame reception process which the radio | wireless data communication apparatus which concerns on embodiment of this invention performs as a subunit | mobile_unit or a relay machine. The figure which showed the example of the processing flow of the survival notification frame reception process and survival response frame transmission process which the wireless data communication apparatus which concerns on embodiment of this invention performs as a relay machine. 6 is an example of a processing flow of survival notification frame reception and survival response frame transmission processing executed as a base unit by the wireless data communication apparatus according to the embodiment of the present invention. The figure which showed the example of a mode that a survival notification frame and a survival response frame were transmitted / received, and the structure of a survival notification frame in the radio | wireless communication network system which concerns on the modification of embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a configuration of a wireless data communication apparatus according to an embodiment of the present invention and a wireless communication network system configured using the wireless data communication apparatus.

  As shown in FIG. 1A, a wireless data communication apparatus 10 according to an embodiment of the present invention includes an MPU (Micro Processing Unit) 11 serving as a control unit, two wireless communication units 12, a timer 14, a wired LAN ( (Local Area Network) communication unit 15, network configuration information storage unit 16, line state information storage unit 17, line state display unit 18 and the like are connected.

  The wireless communication unit 12 includes an antenna 13 and has a function of performing transmission / reception with a wireless carrier wave and modulating / demodulating the carrier wave with the wireless communication unit 12 included in another wireless data communication device 10. . The MPU 11 is configured by a semiconductor integrated circuit microprocessor or the like, and controls the wireless communication unit 12 to control transmission and reception according to a predetermined protocol. The wired LAN communication unit 15 is configured by an interface control circuit with a wired LAN such as Ethernet (registered trademark), and enables the MPU 11 to be connected to an external wired LAN. The timer 14 is a timing device, and notifies the MPU 11 that a predetermined time has come, a predetermined time has passed, and the like.

  The network configuration information storage unit 16 and the line state information storage unit 17 are configured on a memory (not shown) connected to the MPU 11. The network configuration information storage unit 16 stores, for example, interconnection relationship information, survival information, and the like regarding the parent device 20, the relay device 30, and the child device 40 included in the wireless communication network system 100 as illustrated in FIG. . Further, the line state information storage unit 17 stores good / bad state information of the wireless communication line connecting the base unit 20, the relay unit 30, and the slave unit 40. Details of these storage units will be described separately with reference to the drawings.

  Next, as shown in FIG. 1B, the wireless communication network system 100 is configured by connecting a parent device 20, a relay device 30, and a child device 40 in a tree shape. Here, as the master unit 20, the relay unit 30, and the slave unit 40, the wireless data communication apparatus 10 described above is used.

  In FIG. 1B, the wireless communication path from the base unit 20 to the handset 40 (# 1 to # 3) is a path indicated by a solid line via the relay unit 30 (# 1). Normally, this solid communication path is used. In that case, of the two wireless communication units 12 included in the relay device 30 (# 1), one wireless communication unit 12 (line A) is used for communication with the parent device 20, and the other wireless communication unit 12 is used. (Line B) is used for wireless communication with the slave unit 40.

  On the other hand, in the main unit 20 and the sub unit 40, only one of the two wireless communication units 12 is used. Therefore, when the relay device 30 (# 2) is usable, it is indicated by a broken line from the master device 20 to the slave device 40 (# 1 to # 3) via the relay device 30 (# 2). Used for the second communication path. Such a second communication path is used as a backup communication path when a failure occurs. However, since the second communication path is not used in normal communication, it may be considered that there is no normal communication path. Further, in the present embodiment, the configuration of the second communication path that passes through the repeater 30 (# 2) is not essential.

  In FIG. 1B, a parent LAN is connected to the wired LAN communication unit 15 of the parent device 20. A server device that performs overall management of the wireless communication network system 100, an operator terminal, management devices of various other systems, and the like are connected to the parent-side LAN. Further, the handset side LAN is connected to the wired LAN communication unit 15 of the handset 40, and various control devices for plant monitoring and actuators are connected to the handset side LAN.

  FIG. 2 is a diagram illustrating an example of another configuration of the wireless communication network system according to the embodiment of the present invention. In the wireless communication network system 100 shown in FIG. 1B, only one relay device 30 (# 1) is interposed between the parent device 20 and the child devices 40 (# 1 to # 3). In the wireless communication network system 100a shown in FIG. 2, two relay devices 30 (# 1, # 2) are interposed between the parent device 20 and the child devices 40 (# 1, # 3). . Further, the relay device 30 (# 2) and the slave device 40 (# 2) are mixedly connected to the lower side of the relay device 30 (# 1).

  Thus, in the present embodiment, the number of relay devices 30 interposed between the parent device 20 and the child device 40 is not limited to a specific number. Further, the relay device 30 and the slave device 40 may be connected in a mixed manner adjacent to the lower side of the parent device 20 or the relay device 30, and the number thereof is not limited to a specific number. . Further, a relay device 30 (# 3, # 4) may be provided to provide a backup second communication path as indicated by a broken line.

  FIG. 3 is a diagram showing an example of the configuration of the network configuration information storage unit 16 in the wireless data communication apparatus 10. As shown in FIG. 3, the network configuration information storage unit 16 includes a lower-level machine side routing table 161, an upper-level machine side routing table 162, and an own machine information table 163.

  The lower device side routing table 161 is configured to include fields of a lower device ST (Station) number, a lower device MAC address (Media Access Control address), an adjacent lower device MAC address, and a lower device survival status. Here, the subordinate machine refers to the repeater 30 or the slave unit 40 located on the communication path from the own machine to the terminal slave unit 40, and the adjacent subordinate machine is a partner with which the own machine directly performs wireless communication. The repeater 30 or the slave unit 40 that is determined to be. The ST number is a device identification number assigned to each of the parent device 20, the relay device 30, and the child device 40 included in the wireless communication network systems 100 and 100a.

  That is, the lower-level machine ST number is an ST number assigned to the relay machine 30 and the child machine 40 that are lower-level machines for the own machine. The lower-level machine MAC address is the MAC address for the lower-level machine, and the adjacent lower-level machine MAC address is the MAC address of the lower-level machine that is adjacent to the own machine (that is, a partner that directly communicates wirelessly). .

  That is, the lower-level machine MAC address is information for specifying a transmission destination when a message or data (hereinafter referred to as a frame) having a predetermined format is transmitted from the own machine to the lower-level machine. Is information for determining an adjacent lower-level device to which the frame is to be transmitted when the transmission destination of the frame is not an adjacent lower-level device.

  In the lower-level machine side routing table 161, a set of these lower-level machine MAC addresses and adjacent lower-level machine MAC addresses is stored in association with all lower-level machines, that is, lower-level machine ST numbers. Therefore, the number of records in the lower level machine side routing table 161 is the same as the number of lower level machines existing in the lower level of the own machine. In the case of the slave unit 40, since there is no lower level machine, the lower level machine side routing table 161 does not exist or may exist, but its contents are empty.

  Furthermore, in the present embodiment, the low-level machine survival status field is provided in the record of the low-level machine side routing table 161, and the low-level machine survival status field is designated by the low-level machine ST number field. Information on the survival status of the relay device 30 or the slave device 40 is stored. Here, if the own device has received a survival notification frame for notifying that “the own device (lower device) is operating normally” transmitted from the lower device every predetermined time, the lower device Is determined to be alive, and if the alive notification frame has not been received, it is determined that the subordinate machine is not alive. Then, the determination result is stored in the field of the low-level machine survival status.

  As described above, the parent device 20 (or the relay device 30) determines whether the lower device is alive or not, depending on whether or not it receives a survival notification frame that the lower device autonomously transmits. Therefore, it is determined that the lower-level machine is not alive when the lower-level machine is not operating normally or when the communication path from the lower-level machine to the own machine is interrupted.

  Further, in the case of the parent device 20, the lower device side routing table 161 has lower device existence information on all the relay devices 30 and the child devices 40 included in the wireless communication network system 100, 100a. In effect, the parent device 20 can manage the survival information of all the relay devices 30 and the child devices 40.

  Next, the higher-level machine side routing table 162 is configured to include the fields of the adjacent higher-level machine ST number and the adjacent higher-level machine MAC address. Here, the host device refers to the parent device 20 or the relay device 30 included in the communication path from the own device to the parent device 20, and the adjacent upper device is a partner with which the own device directly performs wireless communication. Refers to the master unit 20 or the relay unit 30 defined.

  Here, in the case of the tree-structured wireless communication network systems 100 and 100a as shown in FIG. 1B and FIG. 2, there is only one adjacent higher-level device. Therefore, the higher-level machine side routing table 162 is composed of one record for the adjacent higher-level machine. Further, since there is no host device in the parent device 20, the host device side routing table 162 does not exist or may exist, but the content is empty.

  Next, the own device information table 163 includes fields of own device ST number, own device MAC address, and own device type. The own device information table 163 includes a record for one own device.

  Here, the own device type is information for setting whether the own device is the parent device 20, the relay device 30, or the child device 40. That is, the wireless data communication device 10 operates as one of the parent device 20, the relay device 30, or the child device 40 based on the information set in the field of the own device type.

  In the present embodiment, a tree-like wireless communication network system 100.100a is formed by the lower-level machine side routing table 161, the higher-level machine side routing table 162, and the own machine information table 163 stored in the network configuration information storage unit 16 described above. The connection relationship (radio communication partner) among the parent device 20, the relay device 30, and the child device 40 is fixedly determined at least during normal operation.

  If any one of the relay devices 30 included in the wireless communication network systems 100 and 100a does not operate or a failure occurs in any communication path, a communication path or the like is used to recover from the failure. Can be changed as appropriate, but in this embodiment, the changing method and the like are not mentioned.

  However, if a second communication path for backup as shown by a broken line in FIG. 1B or FIG. 2 is prepared, the path can be easily changed. In that case, the lower-level machine side routing table 161 and the higher-level machine side routing table 162 for the second communication path may be prepared separately from those used in normal times. This situation also applies to the line state information storage unit 17 described below.

  FIG. 4 is a diagram showing an example of the configuration of the line state information storage unit 17 in the wireless data communication apparatus 10. As shown in FIG. 4, the line state information storage unit 17 includes a lower unit side line state table 171 and an upper unit side line state table 172.

  The lower device side line status table 171 includes fields of an adjacent lower device ST number, a lower device side adjacent line status, and a survival notification frame non-reception counter. Here, information indicating whether or not there is a communication failure in the wireless communication line between the own device and the adjacent lower device specified by the adjacent lower device ST number is stored in the lower device side adjacent line state field.

  In the present embodiment, when the master unit 20 or the relay unit 30 confirms the reception of the survival notification frame transmitted from the subordinate unit every predetermined time, and if the reception confirmation cannot be continuously performed a predetermined number of times, It is determined that the equipment side adjacent line status is “abnormal”, and the information is stored in the lower equipment side adjacent line status field. In addition, the number of times that the reception could not be confirmed is stored in the field of the survival notification frame non-reception counter.

  Here, the number of records in the lower device side line status table 171 is the same as the number of the adjacent lower devices of the own device. Further, the slave unit 40 does not or may have the lower unit side line state table 171, but its contents are empty.

  The upper device side line state table 172 includes fields of the adjacent upper device ST number, the upper device side adjacent line state, and the survival response frame non-reception counter. Here, the information indicating the state of the wireless communication line between the own device and the adjacent higher-level device specified by the adjacent higher-level device ST number is stored in the higher-level device side adjacent line status field.

  In the present embodiment, when the relay device 30 or the slave device 40 confirms the reception of the survival response frame transmitted from the host device every predetermined time, and if the reception confirmation cannot be continuously performed a predetermined number of times, It is determined that the equipment side adjacent line status is “abnormal”, and the information is stored in the upper equipment side adjacent line status field. Further, the number of times that the reception could not be confirmed is stored in the field of the survival response frame non-reception counter.

  Note that the number of records in the upper apparatus side line state table 172 is one. Further, although the host device side line state table 172 does not exist or may exist in the parent device 20, the content is empty.

  FIG. 5 is a diagram showing an example of the configuration of a survival notification frame and a survival response frame used in the wireless communication network systems 100 and 100a according to the embodiment of the present invention. As shown in FIG. 5, each survival notification frame (f1, f4) and survival response frame (f2, f3, f5) includes a transmission destination address, a transmission source address, a data type, and transmission data.

  Here, the transmission destination address is the MAC address of the parent device 20, relay device 30 or child device 40 of the frame, and the transmission source address is the parent device 20, relay device 30 or child device of the frame source. 40 MAC addresses. The data type indicates whether the frame is a survival notification frame or a survival response frame. Further, as the transmission data, the ST number of the parent device 20, the relay device 30, or the child device 40 that is the transmission source of the frame is stored.

  Here, the survival notification frame (f1) is a survival notification frame transmitted from the child device 40 toward the parent device 20, and the child device 40 transmits this type of survival notification frame (f1) at predetermined time intervals. . The survival response frame (f2) is a survival response frame that is sent back to the slave unit 40 that has transmitted the survival notification frame (f1) when the relay device 30 receives the survival notification frame (f1) from the slave unit 40. It is. The survival response frame (f3) is a survival response frame that is sent back to the slave unit 40 that has transmitted the survival notification frame (f1) when the master unit 20 receives the survival notification frame (f1) from the slave unit 40. It is.

  Similarly, the survival notification frame (f4) is a survival notification frame that the relay device 30 transmits to the parent device 20, and the relay device 30 transmits this type of survival notification frame (f4) at predetermined time intervals. . The survival response frame (f5) is a survival response frame that is sent back to the relay device 30 that has transmitted the survival notification frame (f4) when the base unit 20 receives the survival notification frame (f4) from the relay device 30. It is.

  FIG. 6 is a diagram illustrating an example of a state in which a survival notification frame and a survival response frame are transmitted and received in the wireless communication network systems 100 and 100a according to the embodiment of the present invention.

  First, referring to FIG. 6A, one relay device 30 is connected to the lower level of the base device 20, and two slave devices 40 (# 1, # 2) are connected to the lower level of the relay device 30. The case will be described. The network system to be explained in this case is assumed to be the wireless communication network system 100 shown in FIG. In FIG. 6, the thick arrow represents the movement of the survival notification frame, and the thin line arrow represents the movement of the survival response frame.

  In FIG. 6A, the slave unit 40 (# 1) transmits a survival notification frame (f1) to the master unit 20 (step S01). Receiving the survival notification frame (f1), the relay device 30 transfers the survival notification frame (f1) to the parent device 20 (step S02) and transmits a survival response frame (f2) to the child device 40 (# 1). (Step S03). Next, the master unit 20 that has received the survival notification frame (f1) transmits a survival response frame (f3) to the slave unit 40 (# 1) (step S04). At this time, the relay device 30 receives the survival response frame (f3) from the parent device 20 toward the child device 40 (# 1), but keeps the survival response frame (f3) at the own device, and the child device 40 Do not forward to (# 1). By not transmitting the survival response frame (f3) addressed to the child device 40 (# 1) to the child device 40 (# 1), the number of frames transmitted and received in the wireless communication network systems 100 and 100a can be reduced.

  Similarly, the slave unit 40 (# 2) transmits a survival notification frame (f1) to the master unit 20 (step S05). The relay device 30 that has received the survival notification frame (f1) transfers the survival notification frame (f1) to the parent device 20 (step S06) and transmits a survival response frame (f2) to the child device 40 (# 2). (Step S07). Next, the master unit 20 that has received the survival notification frame (f1) transmits a survival response frame (f3) to the slave unit 40 (# 2) (step S08). At this time, the relay device 30 receives the survival response frame (f3) from the parent device 20 toward the child device 40 (# 2), but keeps the survival response frame (f3) at the own device, and the child device 40 Do not forward to (# 2).

  Further, the relay device 30 transmits a survival notification frame (f4) to the parent device 20 (step S09). The base unit 20 that has received the survival notification frame (f4) transmits a survival response frame (f5) to the relay unit 30 (step S10).

  While transmission / reception of the survival notification frames (f1, f4) and the survival response frames (f2, f3, f5) as described above is performed, the parent device 20 includes the child devices 40 (# 1, # 2) and the relay device 30. When the existence notification frame (f1, f4) is received (steps S02, S06, S09), the information of “survival” is stored in the lower unit survival status field of the lower unit side routing table 161 of the own unit. On the other hand, when the survival notification frame (f1, f4) to be received is not received in steps S02, S06, and S09, “non-survival” information is displayed in the lower-level machine survival status field of the lower-level machine side routing table 161 of the own machine. Is stored.

  Further, when the relay unit 30 and the base unit 20 receive the survival notification frame (f1, f4) in steps S01, S02, S05, S06, and S09, the lower unit side line state table 171 of the lower unit side of the own unit “Normal” is stored in the adjacent line status on the device side. Further, when the existence notification frame (f1, f4) to be received is not received in steps S01, S02, S05, S06, and S09, the lower unit side adjacent line of the lower unit side line state table 171 of the own unit Stores "abnormal" in the status.

  Further, when the slave unit 40 (# 1, # 2) and the relay unit 30 receive the survival response frame (f2, f3, f5) in steps S03, S04, S07, S08, S10, “Normal” is stored in the upper unit side adjacent line state of the upper unit side line state table 172. If the survival response frame (f2, f3, f5) to be received is not received in steps S03, S04, S07, S08, and S10, the host device side of the host device side line status table 172 of its own device Store "abnormal" in the adjacent line status.

  Next, with reference to FIG. 6B, a case will be described in which the relay devices 30 (# 1, # 2) are arranged in two stages and one slave device 40 is connected to the lower level of the relay device 30. In this case, it is assumed that the network system to be explained is the wireless communication network system 100a shown in FIG.

  In FIG. 6B, the slave unit 40 transmits a survival notification frame (f1) to the master unit 20 (step S11). The relay station 30 (# 2) that has received the survival notification frame (f1) transfers the survival notification frame (f1) to the upper relay station 30 (# 1) (step S12), and also transmits a survival response to the slave unit 40. The frame (f2) is transmitted (step S13).

  Next, the relay device 30 (# 1) that has received the survival notification frame (f1) transferred from the relay device 30 (# 2) transfers the survival notification frame (f1) to the parent device 20 (step S14). ), The survival response frame (f2) is transmitted to the repeater 30 (# 2) (step S15). At this time, the relay device 30 (# 1) receives the survival response frame (f2) toward the child device 40, but keeps the survival response frame (f2) at the own device and transfers it to the child device 40. Do not do.

  Next, the master unit 20 that has received the survival notification frame (f1) transmits a survival response frame (f3) to the slave unit 40 (step S16). At this time, the relay device 30 (# 1) that has received the survival response frame (f3) from the parent device 20 toward the child device 40 keeps the survival response frame (f3) at its own device, and the lower relay device 30. Do not forward to (# 2).

  Further, the relay device 30 (# 2) transmits a survival notification frame (f4) to the parent device 20 (step S17). The upper relay device 30 (# 1) that has received the survival notification frame (f4) transfers the survival notification frame (f4) to the parent device 20 (step S18) and to the lower relay device 30 (# 2). A survival response frame (f5) is transmitted (step S19).

  Next, the base unit 20 that has received the survival notification frame (f4) transmits a survival response frame (f5) to the relay unit 30 (# 2) (step S20). Next, the relay device 30 (# 1) that has received the survival response frame (f5) from the parent device 20 toward the relay device 30 (# 2) keeps the survival response frame (f5) in its own device, Is not transferred to the repeater 30 (# 2).

  Further, the relay device 30 (# 1) transmits a survival notification frame (f4) to the parent device 20 (step S21). The base unit 20 that has received the survival notification frame (f4) transmits the survival response frame (f5) to the relay unit 30 (# 1) (step S22).

  Also in this case, in the same manner as the procedure described with reference to FIG. 6A, the lower device side routing table in each of the parent device 20, the relay devices 30 (# 1, # 2), and the child device 40 is appropriately used. It is possible to define information to be stored in the lower unit survival state field 161, the lower unit side adjacent line state field of the lower unit side line state table 171, and the upper unit side adjacent line state field of the upper unit side line state table 172. it can.

  FIG. 7 is a view showing an example of an external perspective view of the wireless data communication apparatus 10 according to the embodiment of the present invention. As shown in FIG. 7, the wireless data communication apparatus 10 is configured such that functional blocks such as the MPU 11 and the wireless communication unit 12 illustrated in FIG. Two antennas 13 respectively corresponding to the lines A and B (see FIG. 1) are provided so as to protrude to the outside of the housing 101.

  In addition, on the front surface of the housing 101, two display lamps 181 are provided so as to correspond to the wireless lines (line A and line B) when the two wireless communication units 12 communicate with the other wireless data communication apparatuses 10, respectively. Is provided. These display lamps 181 are made of a light emitting diode or the like, and display the quality (normal or abnormal) of the state of each wireless line. The quality of the line status displayed on the display lamp 181 is determined based on information stored in the lower-level machine side line status table 171 and the higher-level machine side line status table 172 of the line status information storage unit 17.

  FIG. 8 is a diagram illustrating an example of lighting conditions of the display lamp 181 of the wireless data communication apparatus 10. In FIG. 8, it is assumed that the master unit 20, the relay unit 30, and the slave unit 40 are used as follows, as shown in FIG. 1B and FIG.

  That is, the line A of the parent device 20 and the child device 40 is used as a first line (wireless line shown by a solid line in FIG. 1B) or FIG. The line B of the slave unit 40 is used as a backup second line (wireless line indicated by a broken line in FIG. 1B and FIG. 2) used when the first line has a failure. It is supposed to be. In addition, one of the line A and the line B of the relay machine 30 is used for communication with a higher-level machine, and the other is used for communication with a lower-level machine.

  If the above is assumed, the display lamp 181 (line A) of the base unit 20 has received a survival notification frame from one or more subordinate units adjacent to the subordinate side of the own unit on the first line. It is turned on in the case (that is, when one or more lower unit side adjacent line state fields of the lower unit side line state table 171 of the first line are “normal”), otherwise it is turned off. Further, the display lamp 181 (line B) of the master unit 20 receives a survival notification frame from one or more subordinate units adjacent to the subordinate unit side of the own unit on the second line (that is, the first unit). 2), the light is turned on when one or more of the lower equipment side adjacent line status fields of the lower equipment side line status table 171 is “normal”, and is otherwise turned off.

  Next, the display lamp 181 (line A) of the repeater 30 receives a survival notification frame from one or more subordinate machines adjacent to the subordinate machine side of the own machine (that is, the subordinate machine side line state table). 171 is turned on when one or more of the adjacent unit side line status fields of “171” are “normal”, and turned off otherwise. Further, the display lamp 181 (line B) of the repeater 30 receives a survival response frame from a higher-level machine adjacent to the higher-level machine (that is, the higher-level machine-side adjacent line status in the higher-level machine-side line status table 172). Lights up when the field is "normal"), otherwise goes off.

  Next, the display lamp 181 (line A) of the slave unit 40 receives a survival response frame from a host unit adjacent to the host unit on the first line (that is, the host unit on the first line). Is turned on when the upper equipment side adjacent line status field of the equipment side line status table 172 is “normal”, otherwise it is turned off. Further, the display lamp 181 (line B) of the slave unit 40 receives a survival response frame from an upper unit adjacent to the upper unit side on the second line (that is, the upper unit on the second line). (When the upper line side adjacent line state field of the side line state table 172 is “normal”), the light is turned off otherwise.

  Here, the display state is identified by turning on or off the display lamp 181, but the display state is identified by changing the color (for example, red and blue) of the lamp to be lit. May be.

  Subsequently, referring to FIG. 9 to FIG. 11, the wireless data communication apparatus 10 according to the embodiment of the present invention transmits / receives the survival notification frame and the survival response frame that are executed as the parent device 20, the relay device 30, or the child device 40. Will be described. FIG. 9 is a diagram illustrating an example of a processing flow of a survival notification frame transmission / transfer process and a survival response frame reception process that the wireless data communication apparatus 10 executes as the slave unit 40 or the relay unit 30.

  The slave unit 40 or the relay unit 30 includes a timer 14 (see FIG. 1), and the timing at which the survival notification frame addressed to the master unit 20 should be transmitted to the timer 14 is based on information such as time designation and repetition time. It has been programmed. The timer 14 instructs the MPU 11 to transmit a survival notification frame when it is time to transmit the survival notification frame.

  The MPU 11 of the slave unit 40 or the relay unit 30 determines whether or not it is the transmission timing of the survival notification frame based on the presence / absence of the survival notification frame transmission instruction from the timer 14 (step S50). If there is (Yes in step S50), a survival notification frame having the own device as the transmission source and the parent device 20 as the transmission destination is transmitted to the adjacent higher-level device of the own device (step S51). On the other hand, when it is not the transmission timing of the survival notification frame (No in step S50), the MPU 11 further determines the presence / absence of a transfer request for the survival notification frame (step S52). The survival notification frame transfer request is issued when the MPU 11 receives a survival notification frame from a lower-level machine in the process shown in FIG.

  If it is determined in step S52 that there is a survival notification frame transfer request (Yes in step S52), the MPU 11 transfers the received survival notification frame to an adjacent higher-level device (step S53). On the other hand, when there is no instruction to transfer the life notification frame (No in step S52), the MPU 11 returns the process to step S50 and waits for the transmission timing of the next life notification frame or the arrival of the transfer request. If the own device is the child device 40, the existence notification frame is not received, and therefore step S53 is not executed.

  In this way, when the MPU 11 transmits or transfers the survival notification frame to the adjacent higher-level machine (steps S51 and S53), the MPU 11 determines whether or not a predetermined time has elapsed (step S54). When the predetermined time has not elapsed (No in step S54), the process waits for the predetermined time to elapse. When the predetermined time has elapsed (Yes in step S54), the MPU 11 determines whether or not a survival response frame has been received from the adjacent host device (step S55). The predetermined time referred to here is a time sufficiently longer than the time when the survival response frame is returned from the adjacent higher level machine after the survival notification frame is transmitted to the adjacent higher level machine.

  When the MPU 11 receives the survival response frame (Yes in step S55), it means that transmission / reception with the adjacent higher-level device has succeeded, so the higher-level device-side adjacent line status field of the higher-level device side line status table 172 “Normal” is stored in (step S56). At this time, a survival response frame non-reception counter field (hereinafter referred to as a survival response frame non-reception counter or simply a non-reception counter) is also cleared to zero. Thereafter, the MPU 11 returns the process to step S50 and waits for the transmission timing of the next survival notification frame or the arrival of a transfer request.

  On the other hand, when the MPU 11 has not received the survival response frame (No in step S55), the MPU 11 counts up the non-reception counter (step S57), and determines whether or not the value of the non-reception counter has exceeded a predetermined value. Determination is made (step S58). If the value of the non-reception counter does not exceed the predetermined value (No in step S58), the MPU 11 returns the process to step S50 and waits for the transmission timing of the next survival notification frame or the arrival of the transfer request.

  Further, when the value of the non-reception counter exceeds a predetermined value (for example, 5) (Yes in step S58), it means that the survival response frame has not been received, for example, five consecutive times from the adjacent host device. It is determined that there is some failure in the line with the host machine, and “abnormal” is stored in the host machine side adjacent line status field of the host machine side line status table 172 (step S59). Thereafter, the MPU 11 returns the process to step S50 and waits for the transmission timing of the next survival notification frame or the arrival of a transfer request.

  FIG. 10 is a diagram illustrating an example of a processing flow of a survival notification frame reception process and a survival response frame transmission process executed by the wireless data communication apparatus 10 as the relay device 30.

  The MPU 11 of the relay device 30 first determines whether or not a survival notification frame transmitted or transferred from an adjacent lower-level device has been received (step S60), and if the survival notification frame has been received (step S60). Yes), since the communication line on the adjacent lower unit side is operating normally, “normal” is stored in the lower unit side adjacent line state field for the adjacent lower unit in the lower unit side line state table 171. (Step S61). At this time, the survival notification frame non-reception counter field (hereinafter referred to as the survival notification frame non-reception counter or simply the non-reception counter) for the adjacent lower-level machine is also cleared to zero.

  Next, the MPU 11 issues a transfer request instructing to transfer the received existence notification frame to a higher-level machine (step S62). When this transfer request is issued, the transfer request is recognized in step S52 of FIG. 9, and the survival notification frame is transferred to the adjacent host device in step S52.

  Next, the MPU 11 transmits a survival response frame to the transmission source of the survival notification frame as a response to the received survival notification frame (step S63). In this case, the destination may be an adjacent lower-level device that has transmitted the received survival notification frame.

  Next, the MPU 11 recognizes the existence of the child device 40 or the relay device 30 that is the transmission source of the existence notification frame by receiving the existence notification frame, and the lower unit side routing table 161 indicates the existence notification frame. “Surviving” is stored in the low-level machine survival status field whose transmission source is the low-level machine (step S64). Thereafter, the MPU 11 returns the process to step S60 and waits for reception of the next survival notification frame.

  On the other hand, if it is determined in step S60 that no survival notification frame has been received (No in step S60), the MPU 11 determines whether or not a predetermined time has elapsed (step S65), and the predetermined time has elapsed. If not (No in step S65), the process returns to step S60. When the predetermined time has elapsed (Yes in step S65), the MPU 11 counts up the non-reception counter of the survival notification frame (step S66).

  Next, the MPU 11 determines whether or not the value of the non-reception counter has exceeded a predetermined value (step S67). When the value of the non-reception counter has not exceeded the predetermined value (No in step S67), the MPU 11 The process returns to step S60. Further, when the value of the non-reception counter exceeds a predetermined value (for example, 5) (Yes in step S67), the MPU 11 has not received the survival notification frame from the adjacent lower-level machine, for example, five times consecutively. Therefore, it is determined that there is some failure in the line with the adjacent lower unit, and “abnormal” is stored in the lower unit side adjacent line state field for the adjacent lower unit in the lower unit side line state table 171 ( Step S68).

  In this case, the MPU 11 has not continuously received the survival notification frame to be received a predetermined number of times (for example, 5 times), so the slave unit 40 or relay device that is the transmission source of the survival notification frame This means that the presence of 30 could not be recognized. Therefore, the MPU 11 stores “non-survival” in the low-level machine survival status field with the transmission source of the survival notification frame as a low-level machine in the low-level machine side routing table 161 (step S69). Thereafter, the MPU 11 returns the process to step S60 and waits for reception of the next survival notification frame.

  FIG. 11 is a diagram illustrating an example of a processing flow of survival notification frame reception and survival response frame transmission processing executed by the wireless data communication apparatus 10 as the parent device 20. However, the processing flow executed by the parent device 20 is different from the processing flow executed by the relay device 30 shown in FIG. 10 except that the processing corresponding to step S62 in FIG. 10 is not included in FIG. Since it is almost the same, the description is omitted.

  Note that step S62 in FIG. 10 is a process for causing the relay device 30 to transfer the survival notification frame received from the lower device to the upper device. Since the upper device does not exist in the parent device 20, the parent device 20 There is no need to execute the processing corresponding to step S62.

  As described above, according to the present embodiment, the slave unit 40 and the relay unit 30 transmit the survival notification frame addressed to the master unit 20 at a predetermined time, for example, at the timing indicated by the timer 14. The master unit 20 knows the presence or absence of each slave unit 40 and the relay unit 30 by receiving the existence notification frame from each slave unit 40 and the relay unit 30 or by determining that it does not receive it. Can do. The result is stored in the subordinate machine survival status field of the subordinate machine side routing table 161 of the network configuration information storage unit 16 of the master machine 20. Therefore, the base unit 20 can manage the survival status of the lower level machine by using the lower level machine side routing table 161.

  Further, the survival notification frame in this case is a frame that is not transmitted according to the transmission instruction of the parent device 20 but is autonomously transmitted by each child device 40 and the relay device 30. Accordingly, the base unit 20 does not need to transmit a transmission instruction frame to each of the child units 40 and the relay unit 30. Therefore, as compared with the conventional case of transmitting a transmission instruction frame such as a ping command, the wireless communication is performed. The number of frames transmitted and received in the network system 100 (100a) is greatly reduced.

  Further, in the present embodiment, each of the master unit 20, the relay unit 30, and the slave unit 40 has received a life notification frame from the adjacent lower unit every predetermined time, and the predetermined time from the adjacent upper unit. Based on the fact that the survival response frame is received every time, it is possible to know the line state between the other parent device 20, the repeater device 30, and the child device 40 adjacent to the lower side and the upper side of the own device. As a result, the lower unit side adjacent line state field and the upper unit side line state table 172 of the lower unit side line state table 171 of the line state information storage unit 17 of each of the master unit 20, the relay unit 30, and the slave unit 40. Is stored in the adjacent line status field on the higher-level machine side. Further, the lower machine side adjacent line state and the upper machine side adjacent line state are displayed on the display lamp 181.

  Accordingly, the maintenance manager of the wireless communication network system 100 (100a) can identify the relay device 30 and the child device 40 that are not communicably connected to the parent device 20, and further, the maintenance at the site. For the staff, it becomes easy to specify the faulty (abnormal) repeater 30 or slave unit 40 or the fault (abnormal) line connecting them.

  Furthermore, in this embodiment, since the subunit | mobile_unit 40 can determine automatically the timing which transmits a survival notification frame, the transmission timing is obtained from the sensor and monitoring apparatus which were connected to the own machine. Both timings can be appropriately adjusted so as not to compete with the timing for transmitting information to the base unit 20. Therefore, in order to avoid contention between the timing when the survival notification frame and the survival response frame are transmitted / received between the slave device 40 and the parent device 20 and the timing when the plant monitoring data and control data are transmitted / received, The timing can be adjusted or easily adjusted.

  Subsequently, an embodiment obtained by modifying a part of the embodiment described above will be described. FIG. 12 is a diagram illustrating a state in which a survival notification frame and a survival response frame are transmitted and received and a configuration example of a survival notification frame in a wireless communication network system according to a modification of the embodiment of the present invention. In the modification of this embodiment, for example, a plurality of relay devices 30 (# 1, # 2) are interposed between the parent device 20 and the child device 40 as in the wireless communication network system 100a shown in FIG. Is assumed.

  In the modification of this embodiment, the transmission source of the survival notification frame is limited to the slave unit 40. Therefore, the relay device 30 does not need to be the transmission source of the survival notification frame, and merely relays (transfers) the transmission.

  As shown in FIG. 12A, the survival notification frame transmitted from the child device 40 to the parent device 20 is received by the relay device 30 (# 2) (step S81), and the relay device 30 (# 1). (Step S82). At this time, the survival notification frame transferred from the relay device 30 (# 2) to the relay device 30 (# 1) is shown as the survival notification frame (f6) of the relay device 30 (# 2) in FIG. In addition, the ST number of the repeater 30 (# 2) is added to the transmission data portion.

  Similarly, when the survival notification frame (f6) is received by the relay device 30 (# 1) and transferred to the parent device 20 (step S84), the survival notification frame is relayed as shown in FIG. As shown as the survival notification frame (f7) of the machine 30 (# 1), the ST number of the relay machine 30 (# 1) is further added to the transmission data portion.

  Accordingly, the master unit 20 acquires the ST numbers of the slave unit 40 and the relay unit 30 stored in the transmission data part, so that the slave unit 40 and the relay unit 30 that are communicably connected to the own unit are obtained. Can be identified. That is, even if the base unit 20 does not receive the survival notification frame with the relay unit 30 as the transmission source, the base unit 20 can be used to determine whether all the slave units 40 and relay units 30 included in the tree-shaped wireless communication network system 100a Non-survival information can be obtained.

  In addition, since the process of the step (S83, S85, S86) of transmitting the survival response frame in response to the step of receiving the survival notification frame (S81, S82, S84) is the same as that of the original embodiment, here Then, the description is omitted.

  As described above, according to the modification of the present embodiment, since it is not necessary for the repeater 30 to transmit a survival notification frame as a transmission source, the number of frames transmitted and received in the wireless communication network system 100a can be further reduced. Can do. Incidentally, as can be seen by comparing FIG. 12A with FIG. 6B, in the modified example of the present embodiment, it is not necessary to transmit / receive frames from S17 to S22 in FIG. 6B. .

10 Wireless Data Communication Device 11 MPU
12 wireless communication unit 13 antenna 14 timer 15 wired LAN communication unit 16 network configuration information storage unit 17 line state information storage unit 18 line state display unit 20 master unit 30 relay unit 40 slave unit 100 wireless communication network system 101 case 161 subordinate unit Side routing table 162 Host machine side routing table 163 Own machine information table 171 Lower machine side line status table 172 Host machine side line status table 181 Indicator lamp

Claims (8)

A wireless communication network system including a parent device, a relay device, and a child device, each of which is a wireless data communication device, wherein communication paths from the parent device to the child device via the relay device are configured in a tree shape Because
Each of the slave unit and the relay unit is
It has a timer that indicates the transmission timing of the survival notification message that notifies the existence of its own machine,
Each time the transmission timing is instructed by the timer, a survival notification message addressed to the parent device is transmitted,
The base unit is
Check whether or not the survival notification message transmitted from each of the slave unit and the relay unit is received every predetermined time,
When reception of the survival notification message is confirmed, it is determined that the child device or the relay device that is the source of the survival notification message is alive,
If reception of the survival notification message is not confirmed, determine that the child device or the relay device that is the source of the survival notification message is not alive,
A wireless communication network system characterized by storing and managing the determined survival or non-survival information of each of the slave unit and the relay unit in its own storage device. A wireless communication network system including a parent device, a relay device, and a child device, each of which is a wireless data communication device, wherein communication paths from the parent device to the child device via the relay device are configured in a tree shape Because
Each of the slaves is
It has a timer that indicates the transmission timing of the survival notification message that notifies the existence of its own machine,
Each time the transmission timing is instructed by the timer, a survival notification message addressed to the parent device is transmitted,
The repeater is
When the existence notification message addressed to the parent device is transmitted from the child device or transferred from the first other relay device adjacent to the own device and the child device on the communication path, the received message is received. The identification information of the own device is added to the existence notification message, and the existence notification message to which the identification information of the own device is added is sent to the parent device or the second adjacent to the own device and the parent device side on the communication path. Forward to other repeaters,
The base unit is
Check every predetermined time whether or not the survival notification message transmitted from each of the slave units has been received,
When reception of the existence notification message is confirmed, the slave unit that is the transmission source of the existence notification message and the relay unit specified by the identification information of the relay unit added to the existence notification message are alive. It is determined that
If reception of the life notification message is not confirmed, a slave unit that is the transmission source of the life notification message and a relay device that is specified by the identification information of the relay device added to the life notification message , It is determined that the repeater except the repeater determined to be alive in the above determination is not alive,
A wireless communication network system characterized by storing and managing the determined survival or non-survival information of each of the slave unit and the relay unit in its own storage device. The repeater further includes:
A survival notification message addressed to the parent device transmitted from the child device or transferred from the first other relay device adjacent to the own device and the child device on the communication path is received, and the received survival message is received. When the notification message is transferred to the parent device or the second other relay device adjacent to the own device and the parent device on the communication path, a survival response message that responds to the existence of the own device is Send the survival notification message to the slave unit or the first other relay device,
In response to the survival notification message, when receiving a survival response message transmitted from the parent device or a second other relay device adjacent to the own device and the parent device on the communication path, Even if the destination of the received survival response message is the slave unit or the third other relay device located on the side of the slave unit with respect to the slave unit on the communication path, the slave unit or the The wireless communication according to claim 1 or 2, wherein transfer of the survival response message to the first other repeater adjacent to the own device and the slave device on the communication path is stopped. Network system. Each of the slave unit, the repeater unit and the master unit is
When the first other wireless data communication device that is the other child device or the relay device is connected adjacent to the child device side on the communication path, the own device and the first other A first display lamp for displaying a quality state of a communication line with the wireless data communication device;
When the other other relay device or the second other wireless data communication device that is the parent device is connected adjacent to the parent device side on the communication path, the own device and the second other device A second display lamp for displaying a quality state of a communication line with the wireless data communication device;
With
The status of the communication line between the own device and the first other wireless data communication apparatus is determined as to whether or not the survival notification message transmitted from the first other wireless data communication apparatus is a predetermined number of times within a predetermined time. Judgment based on whether or not it has been received, the determination result is displayed on the first display lamp,
The state of the quality of the communication line between the own device and the second other wireless data communication device is determined as to whether the survival response message transmitted from the second other wireless data communication device is more than a predetermined number of times within a predetermined time. The wireless communication network system according to any one of claims 1 to 3, wherein a determination is made based on whether or not it is received, and the determination result is displayed on the second display lamp. In a wireless communication network system including a parent device, a relay device, and a child device, wherein a communication path from the parent device to the child device via the relay device is configured in a tree shape, the parent device, the relay A wireless data communication device used as either a machine or a slave unit,
The wireless data communication device
Instructing the transmission timing of a survival notification message for notifying the existence of the own device, and a storage device for storing at least information specifying whether the own device operates as the parent device, the relay device, or the slave device A timer, and
When the own machine operates as the slave or the relay machine,
Each time the transmission timing is instructed by the timer, a survival notification message addressed to the parent device is transmitted,
If your machine operates as a parent machine,
Check whether or not the survival notification message transmitted from each of the slave unit and the relay unit is received every predetermined time,
When reception of the survival notification message is confirmed, it is determined that the child device or the relay device that is the source of the survival notification message is alive,
If reception of the survival notification message is not confirmed, determine that the child device or the relay device that is the source of the survival notification message is not alive,
A wireless data communication apparatus, wherein information on whether each of the determined slave unit and relay unit is alive or non-alive is stored in the storage device and managed. In a wireless communication network system including a parent device, a relay device, and a child device, wherein a communication path from the parent device to the child device via the relay device is configured in a tree shape, the parent device, the relay A wireless data communication device used as either a machine or a slave unit,
The wireless data communication device
Instructing the transmission timing of a survival notification message for notifying the existence of the own device, and a storage device for storing at least information specifying whether the own device operates as the parent device, the relay device, or the child device A timer, and
If your machine operates as a slave unit,
Each time the transmission timing is instructed by the timer, a survival notification message addressed to the parent device is transmitted,
If your machine operates as a repeater,
When the existence notification message addressed to the parent device is transmitted from the child device or transferred from the first other relay device adjacent to the own device and the child device on the communication path, the received message is received. The identification information of the own device is added to the existence notification message, and the existence notification message to which the identification information of the own device is added is sent to the parent device or the second adjacent to the own device and the parent device side on the communication path. Forward to other repeaters,
If your machine operates as a parent machine,
Check every predetermined time whether or not the survival notification message transmitted from each of the slave units has been received,
If reception of the existence notification message is confirmed, the slave unit that is the transmission source of the existence notification message and the relay unit specified by the identification information of the relay unit added to the existence notification message are alive. It is determined that
If reception of the life notification message is not confirmed, a slave unit that is the transmission source of the life notification message and a relay device that is designated by the identification information of the relay device added to the life notification message , It is determined that the repeater except the repeater determined to be alive in the above determination is not alive,
The wireless data communication device, wherein the information on the existence or non-survival of each of the determined child device and the relay device is stored and managed in the storage device. The wireless data communication device
If your machine operates as a repeater,
A survival notification message addressed to the parent device transmitted from the child device or transferred from the first other relay device adjacent to the own device and the child device on the communication path is received, and the received survival message is received. When the notification message is transferred to the parent device or the second other relay device adjacent to the own device and the parent device on the communication path, a survival response message that responds to the existence of the own device is Send the survival notification message to the slave unit or the first other relay device,
In response to the survival notification message, when receiving a survival response message transmitted from the parent device or a second other relay device adjacent to the own device and the parent device on the communication path, Even if the destination of the received survival response message is the slave unit or the third other relay device located on the side of the slave unit with respect to the slave unit on the communication path, the slave unit or the The wireless data according to claim 5 or 6, wherein transfer of the survival response message to the first other repeater adjacent to the own device on the communication path on the communication path is stopped. Communication device. The wireless data communication device
When a first other wireless data communication device is connected adjacent to the slave side on the communication path, a communication line between the own device and the first other wireless data communication device A first indicator lamp that displays a pass / fail state;
When a second other wireless data communication device is connected adjacent to the parent device side on the communication path, a communication line between the own device and the second other wireless data communication device A second indicator lamp that displays a pass / fail status;
With
The status of the communication line between the own device and the first other wireless data communication apparatus is determined as to whether or not the survival notification message transmitted from the first other wireless data communication apparatus is a predetermined number of times within a predetermined time. Judgment based on whether or not it has been received, the determination result is displayed on the first display lamp,
The state of the quality of the communication line between the own device and the second other wireless data communication device is determined as to whether the survival response message transmitted from the second other wireless data communication device is more than a predetermined number of times within a predetermined time. The wireless data communication apparatus according to any one of claims 5 to 7, wherein a determination is made based on whether or not it is received, and the determination result is displayed on the second display lamp.

Images