JP2011066529A - Updating method of firmware, distributed system, maintenance terminal, communication unit, and update program of firmware - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of updating firmware and the relating techniques, capable of reducing the time and labor of the updating work of the firmware, relating to a communication device connected to a reading meter or the like. <P>SOLUTION: The maintenance terminal 10 imparts identification information to a plurality of divided blocks for which the firmware is divided, a radio link is established between the maintenance terminal 10 and a plurality of communication units 20 (step S2), and the divided blocks are transmitted to the respective communication units 20 by broadcast communication (step S4). The communication unit 20 manages the omission of the divided block on the basis of the identification information of the received divided block. The maintenance terminal 10 confirms the presence/absence of the omission to the respective communication units 20 (step S5), and retransmits the divided block to the communication unit 20 in which the omission is present (steps S7-S9). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for transmitting firmware from a maintenance terminal to a communication unit by wireless communication.

  In recent years, when each tenant in a detached house or apartment house, or each tenant in an office building / commercial building is a consumer, a communication device that performs wireless communication is connected to a meter meter such as electricity, gas, water, etc. Meter reading information (that is, power consumption, gas usage, water usage, etc.) via a communication network such as a communication network is sent to a server device for medical examination, enabling remote meter reading. An automatic meter reading system is known (for example, Patent Document 1).

  In such a system, it may be necessary to update the firmware of the communication device connected to the meter-reading meter, for example, due to a change in the communication method.

JP 2008-147844 A

  However, in the conventional system, when updating the firmware of the communication device connected to each meter-reading meter, maintenance personnel wire-connect each individual communication device and the maintenance terminal for maintenance using a communication cable, and update It was done by transferring the firmware for each separately. Therefore, for example, in a large apartment house where a huge number of meter-reading meters are installed, there is a problem that the updating work takes a lot of time and effort. In addition, even in a detached house, there is a problem that it is necessary to update each dwelling unit existing over a wide range in order, which is very time-consuming.

  The present invention has been made in view of the above-mentioned reasons, and the object of the present invention is to reduce the time and effort of firmware update work regarding the firmware of a communication device connected to a meter-reading meter or the like. A firmware update method, a distributed system, a maintenance terminal, a communication unit, and a firmware update program.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a firmware update method for transmitting firmware from a maintenance terminal to a communication unit by wireless communication, wherein a wireless communication is performed between the maintenance terminal and the communication unit. A link establishing step for establishing a link; a dividing step for dividing the firmware into a plurality of divided blocks at the maintenance terminal; an assigning step for assigning identification information to the divided blocks divided by the dividing step at the maintenance terminal; In the maintenance terminal, a transmission step of sequentially transmitting the divided blocks to which the identification information has been given in the granting step to the communication unit by broadcast communication, a receiving step in which the communication unit receives the divided blocks, and the communication unit Given to the divided block Based on the identification information, a management step for managing the presence or absence of missing blocks, and after the transmission of all the divided blocks is completed, for all communication units that the maintenance terminal has established the radio link, A confirmation step for confirming whether or not there is a missing block; and a retransmission step in which the maintenance terminal retransmits only the missing block for a communication unit in which the presence of the missing block is confirmed by the confirmation step. To do.

  According to the present invention, the wireless link is established between the maintenance terminal and the communication unit by the link establishment step, and the maintenance terminal transmits the firmware to the communication unit. The firmware can be transmitted to the communication unit without performing a complicated operation such as transmitting the firmware.

  Further, since the firmware is divided and transmitted by broadcast communication, the firmware can be quickly transmitted to a plurality of communication units. If a communication technique based on flooding is used in broadcast communication, firmware can be transmitted to a large number of communication units more quickly. In addition, since the identification information is given to the divided blocks obtained by dividing the firmware, the maintenance terminal and each communication unit can manage the omission of the divided blocks based on the identification information, and the maintenance terminal can be removed from all the communication units. By confirming the presence of the block, it is possible to accurately grasp the presence of the missing block in each communication unit. Furthermore, by transmitting only the missing block to the communication unit in which the maintenance terminal has the missing block, it is possible to reliably transmit the missing block to the corresponding communication unit while reducing the communication amount.

  According to a second aspect of the present invention, in the first aspect of the present invention, the transmitting step executes broadcast communication in one divided block a plurality of times.

  According to the present invention, since one divided block is transmitted a plurality of times by broadcast communication, the probability that the divided block is transmitted to the communication unit can be increased.

  According to a third aspect of the invention, in the invention according to any one of the first or second aspects, the confirmation step confirms whether or not there is a missing block for each communication unit that has established the wireless link. The processing is sequentially performed on the communication unit, and when the confirmation process fails in a certain communication unit, the confirmation process is performed on the next communication unit.

  According to the present invention, when the confirmation process for confirming whether there is a missing block in a certain communication unit fails, the confirmation process is executed for the next communication unit. Can be executed promptly. In addition, as a feature of wireless communication, the communication unit's communicable time zone may fluctuate due to the influence of wireless noise that occurs according to time. The possibility of succeeding in communication can be increased.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the retransmission step provides a predetermined upper limit number of retransmissions of the missing block.

  According to the present invention, when the number of retransmissions of missing blocks in a certain communication unit reaches the upper limit number, the retransmission process for that communication unit is terminated, so that the retransmission process for the communication unit is not completed. It is possible to avoid a situation in which the firmware update process for is not completed.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the firmware is updated at a predetermined time for all the communication units that have established the wireless link from the maintenance terminal. An instruction step for instructing is further provided.

  According to the present invention, the firmware is updated at the same time when all the communication units reach a predetermined time, so that it is possible to avoid a situation in which the firmware versions differ among the communication units.

  According to a sixth aspect of the invention, in the invention according to any one of the first to fifth aspects, the maintenance terminal manages the firmware versions of all the communication units that have established the wireless link, and all the communication units. An update instruction step for instructing each communication unit to update the firmware only when the two versions match each other is further provided.

  According to the present invention, it is possible to avoid a situation in which firmware versions are different between the communication units.

  The invention according to claim 7 is a distributed system including a maintenance terminal and a communication unit for performing communication by wireless communication, wherein the maintenance terminal and the communication unit include a link establishment means for establishing a wireless link between them. The maintenance terminal includes a dividing unit that divides firmware to be transmitted to the communication unit into a plurality of divided blocks, an adding unit that assigns identification information to the divided blocks divided by the dividing unit, and an identification unit that performs identification. Transmitting means for sequentially transmitting the divided blocks to which the information is given to the slave station by broadcast communication, the communication unit receiving means for receiving the divided blocks, and identification information given to the divided blocks Management means for managing the presence / absence of missing blocks, and the maintenance terminal is capable of transmitting all the divided blocks. After the completion, the confirmation means for confirming the existence of the missing block in all the communication units that have established the wireless link, and only the missing block are retransmitted to the communication unit for which the existence of the missing block is confirmed by the confirmation means. And a retransmitting means.

  According to the present invention, it is possible to provide a distributed system that realizes the firmware update method according to the first aspect of the present invention.

  According to an eighth aspect of the present invention, the maintenance terminal executes the firmware update method according to the first aspect.

  According to the present invention, it is possible to provide a maintenance terminal that implements the firmware update method according to the first aspect of the present invention.

  The invention according to claim 9 is characterized in that the firmware update method according to claim 1 is executed in the communication unit.

  According to this configuration, it is possible to provide a communication unit that realizes the firmware update method shown in (1).

  In the invention of claim 10, a maintenance terminal and a communication unit for performing communication by wireless communication are provided, the maintenance terminal and the communication unit function as a link establishment step for establishing a wireless link between them, and the maintenance terminal is A division step for dividing the firmware into a plurality of division blocks, an addition step for giving identification information to the division blocks divided by the division step, and a division block to which the identification information is given by the addition step are sequentially transmitted by broadcast communication. And a management step for managing the presence / absence of a missing block based on the identification information given to the division block, and a reception step for receiving the division block. The maintenance terminal can send all the divided blocks. A confirmation step for confirming the presence or absence of the missing block in all the communication units that have established the wireless link, and retransmitting the missing block to the communication unit for which the existence of the missing block is confirmed by the confirmation step. It is further characterized by functioning as a retransmission step.

  According to this configuration, it is possible to provide a firmware update program that realizes the firmware update method shown in (1).

  As described above, in the present invention, a wireless link is established between the maintenance terminal and each communication unit, and the maintenance terminal transmits firmware to each communication unit. Therefore, the maintenance terminal is wired to each communication unit. Even if a complicated operation such as transmitting firmware is not performed, the firmware of a plurality of communication devices can be updated promptly and reliably, and the time and effort required to update the firmware can be reduced.

1 is an overall configuration diagram of a distributed system according to an embodiment of the present invention. It is a schematic block diagram which shows the maintenance terminal in the distributed system. It is a schematic block diagram which shows the communication unit in the distributed system. It is the schematic for demonstrating the update method of the firmware in the distributed system. It is a sequence diagram which shows operation | movement of the update method of the firmware. It is a sequence diagram which shows operation | movement of the update method of the firmware. It is a sequence diagram which shows operation | movement of the update method of the firmware. It is a sequence diagram which shows operation | movement of the update method of the firmware.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, a distributed system that implements the firmware update method according to the present embodiment includes a portable maintenance terminal 10 carried by a maintenance worker, and a set of, for example, a detached house or a condominium. The system includes one or a plurality of communication units 20 connected to a meter-reading meter installed in a house, and communicates between the maintenance terminal 10 and the communication unit 20 by wireless communication.

  In the following description, a case where firmware of a plurality of communication units 20 (20a... 20e) is updated by one maintenance terminal 10 will be described. The firmware is a control program for the communication unit 20, and includes two types of firmware: application layer firmware that controls various types of communication unit 20 and network (NET) layer firmware that controls communication control of the communication unit 20. ing.

  As the wireless communication performed between the maintenance terminal 10 and the communication unit 20, for example, a specific low power wireless whose wireless communication frequency is a 429 MHz band is used. For example, when updating firmware in a plurality of communication units 20 installed in a wide area such as a detached house, data may be transmitted to the plurality of communication units 20 by a communication technique based on flooding. preferable.

  In addition, the maintenance terminal 10 and the communication unit 20 are uniquely assigned communication addresses, and the transmission destination and the transmission source of the transmission data can be uniquely specified.

  As shown in FIG. 2, the maintenance terminal 10 includes a control unit 110 that includes a CPU or the like and performs overall control of the entire maintenance terminal 10, a storage unit 120 including, for example, a writable nonvolatile storage device, And a communication unit 130 including a communication module that performs low-power wireless communication. In addition, the control unit 110 includes a division unit 111, a grant unit 112, a transmission control unit 113, a confirmation unit 114, a retransmission control unit 115, an instruction unit 116, and a link establishment unit 117.

  The dividing unit 111 divides the application layer firmware and the NET layer firmware transmitted from the maintenance terminal 10 to the communication unit 20 into a plurality of divided blocks, respectively. The total number of divided blocks and the data amount of each divided block are appropriately determined based on the data transmission / reception capacity in the maintenance terminal 10 and the communication unit 20.

  The assigning unit 112 assigns unique identification information to each divided block divided by the dividing unit 111. Usually, this identification information is given additional information indicating a sequential number and the type of firmware, etc., so that when the communication unit 20 receives the identification information, it is possible to easily find a missing block.

  The link establishment unit 117 controls the communication unit 130 to individually establish a wireless link with each of the plurality of communication units 20 to enable transmission and reception of each control information and divided block.

  The transmission control unit 113 controls the communication unit 130, and broadcasts each divided block to which the identification information is given by the grant unit 112 to the plurality of communication units 20 in which the radio link is established by the link establishment unit 117. Are sent sequentially. In this embodiment, transmission control unit 113 executes broadcast communication in one divided block a plurality of times. By doing in this way, the probability that the communication unit 20 will receive a division | segmentation block increases, and a division | segmentation block can be transmitted to the communication unit 20 more reliably.

  When the transmission control unit 113 completes transmission of all the divided blocks to all the communication units 20, the confirmation unit 114 controls the communication unit 130 to confirm whether each communication unit 20 has any divided blocks missing. More specifically, the confirmation unit 114 sequentially performs confirmation processing for confirming the missing of the divided block with respect to the communication unit 20 for all the communication units 20 with which the wireless link has been established. When the confirmation process of a certain communication unit 20 fails due to a timeout or the like, the confirmation process is executed for the next communication unit 20. Further, after the confirmation process for the communication unit 20 is completed, the confirmation process may be performed again on the communication unit 20 that has failed the confirmation process.

  Based on the confirmation processing by the confirmation unit 114, the retransmission control unit 115 retransmits only the missing divided blocks to the communication unit 20 in which the missing divided blocks are found. At this time, the retransmission control unit 115 continues to retransmit the missing divided blocks until the communication unit 20 can correctly receive them, but a predetermined upper limit may be set for the number of retransmissions.

  The instruction unit 116 controls the communication unit 130 to instruct all communication units 20 that have established wireless links to update the transmitted firmware at a predetermined time. In addition, the instruction unit 116 may manage the firmware versions of all the communication units 20 that have established wireless links. Only when the versions of all the communication units 20 are equal, Firmware update may be instructed.

  The storage unit 120 includes a firmware storage unit 121 and a firmware transfer result file storage unit 122. Firmware to be transmitted is stored in advance in the firmware storage unit 121, and the firmware transfer result file storage unit 122 stores the firmware. Stores a firmware transfer result file indicating which divided blocks have been successfully received in each communication unit 20.

  As shown in FIG. 3, the communication unit 20 includes a control unit 210, a communication unit 220, and a storage unit 230.

  The control unit 210 is configured by a CPU or the like, and manages the presence or absence of missing blocks based on the reception control unit 211 that controls the communication unit 220 to receive the divided blocks and the received identification information of the divided blocks. And a management unit 212.

  The communication unit 220 is configured by a communication module that executes low-power wireless communication, for example, and performs wireless communication with the maintenance terminal 10. Further, the communication unit 220 may perform wireless communication with the communication unit 220 included in the other communication unit 20 and relay communication between the maintenance terminal 10 and the other communication unit 20 (multi-hop). ). Further, the communication unit 220 transmits the divided block transmitted by the broadcast communication to the other communication units 20 by the communication technique based on the flooding, so that the probability that the divided block is transmitted to all the communication units 20. Can be increased.

  The storage unit 230 is composed of, for example, a rewritable nonvolatile storage device, and stores firmware and the like transmitted from the maintenance terminal 10 and received by the communication unit 20.

  Here, an outline of a method for updating firmware according to the present invention will be described with reference to FIG. First, in the software management department 50 that performs maintenance of the communication unit 20, a transfer firmware file F0 of the communication unit 20 is created and copied to the maintenance terminal 10 as a transfer firmware file F0 ′ by wired communication or a memory card. . Here, in the transfer firmware files F0 and F0 ′, the NET layer firmware file F1 as the NET layer firmware and the application layer firmware file F2 as the application layer firmware constitute a single transfer firmware file in a predetermined format. It may also be compressed or combined in a form such as tar or zip. The maintenance terminal 10 obtains the NET layer firmware file F1 and the application layer firmware file F2 by decompressing or decomposing the transfer firmware file F0 '.

  The maintenance terminal 10 first establishes wireless links with all the communication units 20, divides each firmware file F1, F2 into a predetermined amount of information and number, generates divided blocks, and based on flooding. It transmits to the communication unit 20 which established the wireless link sequentially by the communication technique. When the communication unit 20 receives and combines the divided blocks, the firmware files F1 and F2 are copied to the communication units 20 as the NET layer firmware file F1 'and the application layer firmware file F2'.

  Thereafter, each communication unit 20 starts a firmware update process at a predetermined time, whereby the firmware of each communication unit 20 is updated.

  Next, details of the operation of the distributed system shown in FIG. 1 will be described based on the sequence diagrams of FIGS.

  In the following description, it is assumed that five communication units 20, 20 a to 20 e, that require firmware update, are installed, and the communication unit 20 e exists within the direct wireless communication range of the maintenance terminal 10. Without communication, the communication unit 20b relays communication between the maintenance terminal 10 and the communication unit 20e by multi-hop. Also, it is assumed that the NET layer firmware file F1 is transmitted first and then the application layer firmware file F2 is transmitted, and each of the firmware files F1 and F2 is previously copied to the maintenance terminal 10 and stored in the firmware storage unit 121. The explanation will be made assuming that

  First, the maintenance terminal 10 shifts to the update mode when the maintenance staff performs an operation. At this time, the dividing unit 111 divides each of the firmware files F1 and F2 into a plurality of divided blocks, and the assigning unit 112 assigns identification information to each divided block (step S1).

  Next, the link establishment unit 117 of the maintenance terminal 10 transmits a link establishment request to each communication unit 20a... 20e by unicast, and if there is a link establishment response from each communication unit 20, a link by wireless communication is transmitted. Establish (step S2). At this time, if there is no link establishment response from any of the communication units 20, the firmware update may be interrupted, and the following processing is performed only for the communication unit 20 that has received the link establishment response. You may do it.

  Next, the maintenance terminal 10 transmits a firmware transfer request (initialization) by unicast to each communication unit 20 with which a wireless link has been established (step S3). The firmware transfer request (initialization) transmitted in step S2 is a firmware transfer request for initializing each communication unit 20, and the communication unit 20 that has received this firmware transfer request (initialization) is divided, for example, An initialization process such as resetting a counter for counting the number of received blocks or erasing a firmware file used for a past update stored in the storage unit 230 is executed (step S3 ′).

  Next, the transmission control unit 113 sequentially transmits a transmission request for each divided block from the first block, which is the first divided block, to the n-th block, which is the final divided block, by broadcast communication in sequence. (Step S4). Here, the transmission control unit 113 transmits each of the divided blocks from the first block to the n-th block by multiple times (for example, three times) broadcast communication.

  When the transmission of the transfer request for the nth block is completed, the confirmation unit 114 of the maintenance terminal 10 confirms that the divided blocks are missing from all the communication units 20a ... 20e (step S5). Specifically, the confirmation unit 114 controls the communication unit 130 and first transmits a transfer status confirmation request to the first communication unit 20a. When a transfer status confirmation response is received from the communication unit 20a, a transfer status confirmation request is transmitted to the second communication unit 20b, and this processing is performed for all the communication units 20a. The transfer status confirmation response includes information indicating the divided blocks that could not be received by each communication unit 20.

  At this time, if the transfer status confirmation response is not obtained from the communication unit 20 even after a predetermined timeout period, the next wireless unit 20 is not transmitted to the wireless unit 20 again, but is transmitted again. The transfer status confirmation request is transmitted to the communication unit 20 after all the communication units 20 have been checked for missing divided blocks. Send and check for missing divided blocks. In the management unit 212 of each communication unit 20, data indicating which divided blocks are missing is stored in the storage unit 230.

  Also, the confirmation unit 114 performs firmware transfer indicating which divided block has been successfully or unsuccessfully received in each communication unit 20 based on the information regarding missing divided blocks included in the transfer status confirmation response of each communication unit 20. A result file is generated and stored in the firmware transfer result file storage unit 122 (step S6).

  Next, when it is determined in step S5 that there is a missing divided block in any of the communication units 20, the retransmission control unit 115 of the maintenance terminal 10 sets a corresponding missing block for the communication unit 20b. Send. Here, if the communication unit 20b fails to receive the x-th divided block, the retransmission control unit 115 transmits a firmware transfer request storing the x-th divided block to the communication unit 20b. Send in a cast. When the transmission is completed, the confirmation unit 114 transmits a transfer status confirmation request to the communication unit 20b by unicast, and confirms again whether the divided block is missing based on the transfer status confirmation response from the communication unit 20b ( Step S7).

  Here, if there is a missing divided block, the same processing as that in step S7 is performed again to transmit the divided block and confirm the missing divided block. The process similar to step S7 is repeated for a predetermined number of times (here, three times) or no divided block is missing (steps S8 and S9), and the divided block where the missing has occurred in the communication unit 20b is retransmitted. This retransmission process (steps S7 to S9) is performed for all the communication units 20 in which the division block is confirmed to be missing, and the transmission process of the NET layer firmware file to all the communication units 20 is completed.

  Subsequently, the maintenance terminal 10 transmits the application layer firmware file to each communication unit 20. The maintenance terminal 10 holds the application layer firmware file F2 divided into a plurality of divided blocks in step S1, and identification information is given to each divided block.

  The maintenance terminal 10 and each of the communication units 20a ... 20e establish a wireless link by the same processing as in steps S2 to S9 described above (step S10), and perform initialization associated with a firmware transfer request (initialization) ( Steps S11 and S11 ′), the firmware is transferred (Step S12). Further, it is confirmed whether the divided blocks are missing in each communication unit 20 (step S13), and the confirmation result is written in the firmware transfer result file (step S14). Is retransmitted (steps S15 to S17).

  When the transmission of the firmware files F1 and F2 is completed in this way, the instruction unit 116 of the maintenance terminal 10 next instructs the communication unit 20 that has successfully received the firmware files F1 and F2 to update. The instruction processing for starting is started (see FIG. 8).

  Specifically, the instruction unit 116 transmits a firmware update start request by unicast to each communication unit 20 to which a link has been established in step S10, and the communication unit 20 that has received the firmware update start request Then, a firmware update start response is transmitted to the maintenance terminal 10 (step S18). The firmware update start request transmitted by the instruction unit 116 stores the update time at which the communication unit 20 actually updates the firmware. The update time includes the year, month, date, hour, minute, Absolute time or relative time can be specified using at least one of the seconds. In addition, the firmware update start request may include instruction information for instructing update of one or both of the transfer firmware files F1 and F2. In addition, information that causes each communication unit 20 to immediately update the firmware may be included without designating the update time.

  Here, when the update time stored in the firmware update start request is reached, each communication unit 20a... 20e starts updating the firmware with the received divided block (step S19). Note that the firmware update procedure in the communication unit 20 is a known technique, and thus the description thereof is omitted.

  After that, when the firmware update is completed, each communication unit 20a... 20e starts a normal operation after performing a process such as rebooting as necessary.

  In this way, the maintenance terminal 10 can establish a wireless link with a plurality of communication units 20 and can simultaneously transmit firmware to each communication unit 20 using wireless communication. The firmware can be transmitted promptly and surely without the troublesome task of transmitting the firmware by connecting the maintenance terminal 10 to the wired terminal, and the trouble of updating the firmware of the communication unit 20; , Time can be greatly reduced.

  Note that if there is a missing divided block even after the divided block retransmission processing shown in steps S7 to S9 and steps S15 to S17, the maintenance staff connects the maintenance terminal 10 to the communication unit 20 by wire, The files F1 and F2 may be transferred. Thereafter, if the firmware update instruction process shown in step 18 is performed, the firmware can be updated at the same time as the other communication units 20.

  In the firmware update instruction process shown in step S18, if the firmware versions of the communication units 20 do not match, the maintenance terminal 10 may not send a firmware update start request. Thereafter, the firmware of the same version as that of the other communication units 20 is transferred to the communication unit 20 storing the firmware whose version does not match, so that the unintended firmware update can be prevented.

  In the present embodiment, the radio link is not established before the firmware update instruction process shown in step S18, but the maintenance terminal 10 and the maintenance terminal 10 are again connected by the same process as in step S2 or step S10. A wireless link may be established with the communication unit 20.

  The communication unit 20 according to the distributed system is an automatic meter reading in which each communication unit 20 is connected to a meter reading server via a wide area communication network and transmits meter reading information based on an instruction from the examination server. It is also possible to adapt to the communication unit used in the system. In this case, firmware related to communication between the communication unit 20 and the examination server can be updated.

10 maintenance terminal 20 communication unit S1 initialization process step (division step, grant step)
S2, S10 Link establishment step S3, S11 Transmission start step S4, S12 Transmission step, Reception step S5, S13 Missing block confirmation step (management step)
S6, S14 Confirmation information storage step (management step)
S7, S8, S9, S15, S16, S17 Retransmission step S18 Update instruction step F1 NET layer firmware file (firmware)
F2 application layer firmware file (firmware)

Claims (10)

A firmware update method for transmitting firmware from a maintenance terminal to a communication unit by wireless communication,
Establishing a link between the maintenance terminal and the communication unit;
A dividing step of dividing the firmware into a plurality of divided blocks in the maintenance terminal;
An assigning step of giving identification information to the divided blocks divided by the dividing step in the maintenance terminal;
A transmission step of sequentially transmitting the divided blocks to which the identification information has been assigned in the maintenance terminal to the communication unit by broadcast communication;
A receiving step in which the communication unit receives the divided blocks;
A management step for managing the presence or absence of missing blocks based on the identification information given to the divided blocks in the communication unit;
After the transmission of all the divided blocks is completed, a confirmation step for confirming the presence or absence of the missing block for all communication units with which the maintenance terminal has established the radio link;
A firmware update method, comprising: a retransmission step in which the maintenance terminal retransmits only a missing block for a communication unit in which the presence of a missing block is confirmed in the confirmation step. The firmware update method according to claim 1, wherein the transmission step executes broadcast communication in one divided block a plurality of times.   The confirmation step sequentially performs confirmation processing on the communication unit for confirming the presence or absence of a missing block for each communication unit that has established the wireless link. In the communication unit, the confirmation processing is performed. 3. The firmware update method according to claim 1, wherein the confirmation process is executed for a next communication unit when the process fails.   The firmware update method according to claim 1, wherein the retransmission step sets a predetermined upper limit number of times of retransmission of the missing block.   5. The method according to claim 1, further comprising an instruction step for instructing all the communication units that have established the wireless link from the maintenance terminal to update the firmware at a predetermined time. Firmware update method described in 1.   The maintenance terminal manages the firmware versions of all communication units that have established the wireless link, and updates instructions that instruct each communication unit to update the firmware only when the versions of all communication units match. The firmware update method according to claim 1, further comprising a step. A distributed system including a maintenance terminal and a communication unit for performing communication by wireless communication,
The maintenance terminal and the communication unit comprise link establishing means for establishing a radio link between them,
The maintenance terminal is
Dividing means for dividing firmware to be transmitted to the communication unit into a plurality of divided blocks;
An assigning means for giving identification information to the divided blocks divided by the dividing means;
Transmission means for sequentially transmitting the divided blocks to which the identification information is given by the grant means to the slave station by broadcast communication,
The communication unit is
Receiving means for receiving the divided blocks;
Based on the identification information given to the divided blocks, comprising a management means for managing the presence or absence of missing blocks,
The maintenance terminal is
Confirmation means for confirming the presence or absence of the missing block in all communication units that have established the wireless link after transmission of all the divided blocks is completed;
The distributed system further comprising: a retransmission unit that retransmits only the missing block to the communication unit in which the existence of the missing block is confirmed by the confirmation unit.   A maintenance terminal for executing the firmware update method according to claim 1.   A communication unit for executing the firmware update method according to claim 1. A maintenance terminal and a communication unit for performing communication by wireless communication are provided.
Causing the maintenance terminal and the communication unit to function as a link establishment step for establishing a wireless link between them,
A division step of dividing the maintenance terminal into a plurality of divided blocks;
An assigning step of giving identification information to the divided blocks divided by the dividing step;
Function as a transmission step for sequentially transmitting the divided blocks to which the identification information has been given in the grant step to the communication unit by broadcast communication;
A receiving step of receiving the divided block of the communication unit;
Based on the identification information given to the divided blocks, function as a management step for managing the presence or absence of missing blocks,
After the transmission of all the divided blocks to the maintenance terminal, a confirmation step for confirming the presence or absence of the missing block in all the communication units that have established the radio link;
A firmware update program that further functions as a retransmission step for retransmitting a missing block for a communication unit in which the presence of the missing block is confirmed by the confirmation step.

Images