COMMUNICATION UNIT, TIME RECOVERY METHOD, AND PROGRAM

Abstract

To provide a communication unit that contributes to enabling the time of a clock function to be restored even if a power outage occurs for a long period of time without requiring a power source to back up the clock function during a power outage. [Solution] The communication unit is connected to a first power system and a network, and includes a control unit and a time management unit, and the control unit sets priorities for other communication units connected to a power system other than the first power system and that connect via the network after the first power system recovers from a power outage, and after the first power system recovers from a power outage, it receives current time information from the other communication units via the network in accordance with the priorities, and the time management unit restores the time used for measuring time according to the current time information.

Description

[Technical field]

[0001] The present invention relates to a communication unit, a time recovery method, and a program. [Background technology]

[0002] The following documents are cited regarding wireless communication systems that establish wireless connections based on connection priorities.

[0003] Patent Document 1 relates to a wireless communication system in which, when a relay station receives a connection request from a wireless terminal, the relay station determines the master station candidate with the highest connection priority as the optimal master station, and establishes a wireless connection to the optimal master station. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Republished Patent No. 2013 / 061986 Summary of the Invention [Problem to be solved by the invention]

[0005] The following analysis is given by the inventors.

[0006] A communication unit for an ad-hoc network (for example, a smart meter for reading electricity and gas) is equipped with an RTC (Real Time Clock) circuit as a clock function. In order to continue measuring time using the clock function when the power supply that supplies power to such a communication unit is interrupted, the power supply for the RTC circuit is backed up by an electric double-layer capacitor, so that the current time can be measured continuously by the RTC circuit after the power is restored.

[0007] When using an electric double-layer capacitor to back up the power supply for the RTC circuit, the backup time is limited by the capacity of the electric double-layer capacitor, and the clock function cannot be maintained in the event of a long-term power outage. As a result, when the power is restored after a long-term power outage, the time is initialized and cannot be restored.

[0008] In addition, the provision of a backup electric double layer capacitor increases the cost of the communication unit and increases the component mounting area on the printed circuit board in the communication unit. Therefore, there is a need for a method of restoring the time when a power outage is restored that does not use an electric double layer capacitor for backing up the power supply of the RTC circuit.

[0009] The present invention aims to provide a communication unit, a time recovery method, and a program that contribute to enabling the time of a clock function to be restored even during a long power outage without requiring a power source to back up the clock function during a power outage. [Means for solving the problem]

[0010] According to a first aspect of the present invention, there is provided a power supply system connected to a first power supply system and a network, the power supply system including a control unit and a time management unit, The control unit is setting a priority order for other communication units connected to a power supply system other than the first power supply system and connected via the network after the first power supply system is restored from a power outage; receiving current time information from the other communication units via the network in accordance with the priority order after the first power supply system is restored from a power outage; The time management unit, Restoring the time to be measured according to the current time information. A communication unit may be provided.

[0011] According to a second aspect of the present invention, there is provided a power supply system connected to a first power supply system and a network, The communication unit setting a priority order for other communication units connected to a power supply system other than the first power supply system and connected via the network after the first power supply system is restored from a power outage; receiving time information from the other communication units via the network in accordance with the priority order after the first power supply system is restored from a power outage; Restoring the time to be measured according to the time information. A method of time recovery can be provided, which is linked to a specific machine, a computer, that executes the method.

[0012] According to a third aspect of the present invention, there is provided a program for causing a computer to execute a time restoration method.

[0013] These programs can be recorded on a computer-readable storage medium. The storage medium can be a non-transitory medium such as a semiconductor memory, a hard disk, a magnetic recording medium, an optical recording medium, etc. The present invention can also be embodied as a computer program product. Effect of the Invention

[0014] According to the present invention, it is possible to provide a communication unit, a time recovery method, and a program that contribute to enabling the time of the clock function to be restored even during a long-term power outage without requiring a power source to back up the clock function during a power outage. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a block diagram showing an example of a configuration of a communication unit according to the present disclosure. [Diagram 2] 1 is a block diagram showing an example of a configuration of a communication system according to the present disclosure. [Diagram 3] FIG. 1 is a block diagram showing an example of the configuration of a conventional communication unit. [Figure 4]FIG. 2 is a block diagram showing an example of a configuration of a communication unit according to the present disclosure. [Diagram 5] 2 is a block diagram showing an example of the configuration of a control unit of a communication unit according to the present disclosure. FIG. [Figure 6] FIG. 11 is a sequence diagram showing an example of an operation of a communication unit according to the present disclosure. [Figure 7] FIG. 11 is a sequence diagram showing an example of an operation of a communication unit according to the present disclosure. [Figure 8] FIG. 11 is a sequence diagram showing an example of an operation of a communication unit according to the present disclosure. [Figure 9] FIG. 4 is a timing diagram illustrating an example of the operation of a communication unit according to the present disclosure. [Figure 10] FIG. 2 is a diagram showing the configuration of a computer that constitutes a communication unit according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In this disclosure, the drawings may be associated with one or more embodiments. In addition, each embodiment described below may be combined with other embodiments as appropriate, and the present invention is not limited to each embodiment.

[0017] First, an outline of one embodiment will be described with reference to the drawings. Note that the reference numerals in the drawings are given to each element for convenience as an example to aid in understanding, and are not intended to limit the present invention to the illustrated form. Also, the connection lines between blocks in the drawings and the like referred to in the following description include both bidirectional and unidirectional lines. The unidirectional arrows are used to diagrammatically indicate the flow of the main signal (data), and do not exclude bidirectionality.

[0018] FIG. 1 is a block diagram showing an example of the configuration of a communication unit according to the present disclosure. Referring to FIG. 1, a communication unit 350 according to the present disclosure connected to a network 400 is shown. Other communication units 210 and 220 are also connected to the network 400. The communication unit 350 is connected to a first power supply system 390 and the network 400, and includes a control unit 11 and a time management unit 13. The control unit 11 sets the priority of the other communication units 210 and 220 connected to a power supply system 290 other than the first power supply system 390, which is connected via the network 400 after the first power supply system 390 is restored from a power outage. The first power supply system 390 and the power supply system 290 other than the first power supply system 390 may be AC ​​power sources. Each communication unit may be a smart meter for reading electricity and gas.

[0019] After the first power supply system 390 recovers from a power outage, the communication unit 350 receives time information from the other communication unit 210 or 220 via the network 400 in accordance with the priority order. For example, if a higher priority order is assigned to the other communication unit 210 among the other communication units 210 and 220 connected to a power supply system 290 other than the first power supply system 390, the communication unit 350 receives current time information from the other communication unit 210 in accordance with the priority order.

[0020] Next, the communication unit 350 restores the time that the time management section 13 keeps track of in accordance with the current time information.

[0021] As described above, according to one embodiment, it is possible to provide a communication unit, a time recovery method, and a program that contribute to enabling the time of the clock function to be restored even during a long power outage without requiring a power source to back up the clock function during a power outage. Note that according to one embodiment, since a power source to back up the clock function during a power outage, such as an electric double layer capacitor, is not required, it is possible to reduce the component mounting area of ​​the communication unit, and the communication unit can be made smaller.

[0022] [First embodiment] Next, the first embodiment will be described in detail with reference to the drawings. FIG. 2 is a block diagram showing an example of the configuration of a communication system according to the present disclosure. Referring to FIG. 2, the communication system 1000 includes a network 400, a concentrator 100 connected to the network 400, communication units 210, 220, 330, 340, 350, a collection server 600, and a second network 500 to which the concentrator 100 and the collection server 600 are connected. Each communication unit may be a smart meter for reading electricity and gas. The network 400 may be, for example, an ad-hoc network. Hereinafter, it is also referred to as the ad-hoc network 400.

[0023] Data collection devices 215, 225, 335, 345, 355 are connected under each communication unit 210, 220, 330, 340, 350. Each communication unit 210, 220, 330, 340, 350 converts data from the data collection devices 215, 225, 335, 345, 355 into a wireless signal and transmits it to the concentrator 100 via the ad-hoc network 400. The concentrator 100 transmits the data to the collection server 600 via the second network 500, and the data is managed in the collection server 600.

[0024] Moreover, the communication units 210 and 220 having the same power supply system are grouped into a group A200, and the communication units 330, 340, and 350 having the same power supply system are grouped into a group B300. The power supply system of the group A200 is a different power supply system from the power supply system of the group B300. As an example, the power supply system of the group B300 may be the first power supply system 390 described with reference to FIG. 1, and the power supply system of the group A200 may be the power supply system 290 different from the first power supply system 390 described with reference to FIG. 1. Different power supply system IDs are assigned to the different power supply systems, and the same power supply system ID-A is assigned to the communication units 210 and 220 of the group A, and the same power supply system ID-B is assigned to the communication units 330, 340, and 350 of the group B. It is assumed that it is possible to identify that the communication units are connected to different power supply systems from the power supply system IDs assigned to the communication units.

[0025] 3 is a block diagram showing an example of the configuration of a conventional communication unit 350C. The conventional communication unit 350C includes four blocks: a control block 10C, a power supply block 20, a power failure detection block 30, and a wireless block 40, as an example.

[0026] The control block 10C includes a control unit 11C that controls the communication unit 350C, terminates external data 111 from the data collection device, and converts it into wireless data 113, a time management unit (hereinafter also referred to as RTC) 13 that controls the clock function, and an electric double layer capacitor 14 for backing up the RTC 13 in the event of a power outage. The control unit 11C enables time management of the communication unit 350C using time data 112 from the RTC 13.

[0027] The wireless block 40 includes a wireless circuit 12 that converts the wireless data 113 from the control unit 11C into a wireless signal 700 and converts the wireless signal 700 into the wireless data 113 .

[0028] The power supply block 20 includes an AC / DC conversion circuit 21 that converts a first power supply system 390 (hereinafter referred to as AC power supply 390), which may be an alternating current (AC) power supply, into an internal power supply 212, and a power supply circuit 22 that converts the internal power supply 212 into a second internal power supply 221 for the RTC 13.

[0029] The power outage detection block 30 includes a power outage detection circuit 23 that detects a power outage in the AC power supply 390, and a power outage backup capacitor 24 for backing up the power supply circuit 22 that generates the second internal power supply 221 in order to store the time of the power outage in the event of a power outage.

[0030] Next, an example of the configuration of a communication unit according to the present disclosure will be described with reference to the drawings. FIG. 4 is a block diagram showing an example of the configuration of a communication unit according to the present disclosure. The communication unit 350 shown in FIG. 4 is, for example, the communication unit 350 in the block diagram showing an example of the configuration of a communication system 1000 including a communication unit according to the present disclosure shown in FIG. 2. The other communication units 210, 220, 330, and 340 may also have a similar configuration to the communication unit 350 shown in FIG. 4. In FIG. 4, components with the same reference symbols as those in FIG. 3 indicate the same components. Below, the differences between the conventional communication unit 350C shown in FIG. 3 and the communication unit 350 according to the present disclosure shown in FIG. 4 will be mainly described.

[0031] The control block 10 of the communication unit 350 according to the present disclosure shown in Fig. 4 includes a control unit 11 and a time management unit (RTC) 13, but does not include a backup electric double layer capacitor 14 for the RTC 13 included in the control block 10C of the conventional communication unit 350C shown in Fig. 3. Fig. 5 is a block diagram showing an example of the configuration of the control unit 11 of the communication unit according to the present disclosure. Referring to Fig. 5, the control unit 11 of the control block 10 of the communication unit 350 according to the present disclosure includes a record update unit 1101 for electric field strength and power system ID, a connection destination determination unit 1102, a power outage information receiving / storing unit 1103, a power outage information and current time information transmitting unit 1104, and a time correction unit 1105.

[0032] The field strength and power system ID recording and updating unit 1101 has a function of recording and updating the field strength and power system ID in a non-volatile memory (not shown). The connection destination determination unit 1102 has a function of determining the connection destination after power recovery from the field strength and power system ID recorded in the non-volatile memory. The power outage information receiving and storing unit 1103 has a function of receiving and storing power outage information. The power outage information and current time information transmitting unit 1104 has a function of transmitting power outage information and current time information to other communication units. In addition, the time correction unit 1105 has a function of comparing information before and after the power outage and correcting the time.

[0033] Next, the operation of the first embodiment will be described in detail with reference to the drawings. Fig. 6 is a sequence diagram showing an example of the operation of the communication unit according to the present disclosure. With reference to Fig. 6, the operation will be described in which the communication unit 350 belonging to group B300 to which the power supply system ID-B is assigned selects, confirms, and stores the communication unit 210 belonging to a different group A to which a different power supply system ID-A is assigned as the highest priority communication destination to be connected after the power outage is restored, and then performs normal operation.

[0034] In step S601, since the communication unit 350 is in an initialized state when it is first installed and operated, the installer registers the power system ID-B) of group B, which groups communication units of the same power system, in the communication unit 350. At the same time as registering the power system ID, the current time of the communication unit 350 is also set, and then connection and communication with other communication units 210 is performed in step S602.

[0035] In step S602, the communication unit 350 connects to and communicates with multiple other communication units 210, 220 to perform communication in the ad-hoc network 400, and extracts the power supply system ID-A of the other communication unit 210 from the wireless data 113 acquired from the received wireless signal 700. It also measures the field strength of the wireless signal 700 and transmits it to the control unit 11 as data of the wireless data 113. Here, it is assumed that the field strength of the communication unit 210 is the strongest among the communication units in group A.

[0036] Next, in step S603, the field strength and power supply system ID record update section 1101 in the control section 11 confirms and records the field strengths of the other communication units 210 and 220 and the power supply system ID-A obtained in this manner.

[0037] Also, in step S603, the connection destination determination unit 1102 of the control unit 11 assumes that the power system of power system ID-B of group B will suffer a power outage, and selects the communication unit 210 that has a different power system ID-A and has the strongest electric field strength as the communication destination with the highest priority after the power outage is restored.

[0038] Also, considering the possibility that connection / communication with the communication destination with the highest priority cannot be performed after recovery from a power outage, the electric field strength of, for example, the communication unit 220 having a different power supply system ID-A and second or lower electric field strength, and the power supply system ID-A are also recorded and stored in a non-volatile memory (not shown) in the control unit 11 so as not to be erased during and after a power outage. As an example, a table of communication units of communication destinations may be created and recorded in the table. Note that the power supply system ID and electric field strength may change, so that the communication unit with the highest priority is updated and recorded by periodically connecting to other communication units 210 and 220 of communication destinations, communicating, and updating the table of power supply system IDs and electric field strengths.

[0039] Also, in step S604, the electric field strength and power system ID recording and updating unit 1101 in the control unit 11 of the other communication unit 210 records the electric field strength and power system ID-B of the communication unit 350, and the connection destination determination unit 1102 of the control unit 11 of the other communication unit 210 selects and records the communication unit 350 as the communication unit with the highest priority after the power outage is restored based on the electric field strength and power system ID-B of the communication unit 350.

[0040] Next, in step S605, connection and communication are performed via the ad-hoc network 400. Through the communication in step S605, in steps S606 and S607, the communication unit 350 synchronizes its time with the communication destination that will have the highest priority when the power outage is restored, in this case the communication unit 350 synchronizes its time with the communication unit 210, and the communication unit 210 synchronizes its time with the communication unit 350, i.e., the communication unit 350 and the communication unit 210 synchronize their time.

[0041] Thereafter, in step S608, the communication unit 350 transmits the data from the data collection device 355 to the collection server 600 via the concentrator 100 and the second network 500, and the normal operation state is resumed.

[0042] The route in the ad-hoc network 400 through which the communication unit 350 transmits data received from the data collecting device 355 to the collection server 600 via the concentrator 100 and the second network 500 does not need to go through the communication destination with the highest priority after the power outage is restored, that is, the communication unit 210. Also, for example, data from the data collecting device 215 is transmitted to the concentrator 100 via the communication unit 220, which is the shortest route from the communication unit 210 to the concentrator 100, but the communication unit 210 synchronizes the time with the communication unit 350.

[0043] Fig. 7 is a sequence diagram showing an example of the operation of the communication unit according to the present disclosure. Fig. 7 shows the operation from the time when a power outage occurs when the communication unit 350 is in normal operation. The operation of the communication unit shown in Fig. 7 shows the operation of the communication unit 210 and the communication unit 350 shown in Fig. 2, similar to that shown in Fig. 6.

[0044] When a power outage occurs in the power supply system of group B300 to which the communication unit 350 belongs (step S701), in step S702, the communication unit 350 receives a power outage detection signal 231 from the power outage detection circuit 23, and using the power outage detection signal 231 as a trigger, the power outage information receiving and storing unit 1103 in the control unit 11 confirms and stores the power outage time based on the time data 112 from the RTC 13. The process from the occurrence of the power outage in step S701 to the generation of the power outage detection signal 231 and the confirmation and storage of the power outage time in step S702 will be described later with reference to FIG.

[0045] Next, in step S703, the power outage information and current time information transmission unit 1104 in the control unit 11 transmits a power outage notification including the power outage information and the time data 112 from the RTC 13 as the power outage time to the communication unit 210 that is the communication destination with the highest priority after the power outage is restored. In step S705, the communication unit 210 receives the power outage notification transmitted in step S704. At this time, the communication unit 210 determines that the disconnection of the connection / communication from the communication unit 350 in step S706 is due to a power outage, and in step S707, stores the power outage notification including the power outage information and the power outage time transmitted from the communication unit 350.

[0046] Fig. 8 is a sequence diagram showing an example of the operation of the communication unit according to the present disclosure. With reference to Fig. 8, the operation of the communication unit 350 from when it recovers from a power outage to when it recovers the time and performs normal operation will be described. The operation of the communication unit shown in Fig. 8 is the same as that shown in Fig. 6, and shows the operation of the communication unit 210 and the communication unit 350 shown in Fig. 2.

[0047] After recovery from the power outage in step S801, the communication unit 350 connects to and communicates with the communication unit 210, which is the communication destination with the highest priority after recovery from the power outage, based on the electric field strength and power system ID-A stored in step S802, and sends a power outage recovery notification to the communication unit 210 in step S803.

[0048] When the communication unit 210 receives the power failure recovery notification sent in step S804, the communication unit 210 that has received the power failure recovery notification sends the current time to the communication unit 350 that has recovered from the power failure in step S805.

[0049] The communication unit 350 that has recovered from the power outage receives the current time transmitted from the communication unit 210 in step S806 and adjusts the time from the received current time in step S807 to recover.

[0050] Thereafter, the communication unit 350 goes into a normal operation state in step S811.

[0051] Next, the occurrence of a power outage in step S701 in Fig. 7, the generation of the power outage detection signal 231 in step S702, and confirmation and storage of the power outage time will be described with reference to Fig. 9. Fig. 9 is a timing diagram showing an example of the operation of the communication unit according to the present disclosure. Fig. 9 shows (a) the voltage value of the AC power source 390, (b) the voltage value of the internal power source 212, and (c) the voltage value of the second internal power source 221 supplied to the communication unit 350 according to the present disclosure shown in Fig. 4, and (d) the power outage detection signal 231 output by the power outage detection circuit 23. T1, T2, and T3 indicate each time point, T indicates the backup time, and Vth is the power outage detection threshold voltage.

[0052] When the AC power supply 390 fails at time T1, the voltage value of the (b) internal power supply 212 converted by the AC / DC conversion circuit 21 slowly drops while being backed up by the power failure backup capacitor 24. The voltage value of the (b) internal power supply 212 reaches the power failure detection threshold voltage Vth at time T2 and then becomes zero.

[0053] At the same time, the power supply circuit 22 is also backed up, and the voltage value of (c) the second internal power supply 221 can be maintained until time T3, after which the voltage value of (c) the second internal power supply 221 becomes zero.

[0054] On the other hand, when (b) the internal power supply 212 reaches the set power failure detection threshold voltage Vth at time T2, the power failure detection circuit 23 activates the power failure detection signal 231 to the control unit 11. Note that in the present disclosure, as an example, (d) the power failure detection signal 231 activates a low level.

[0055] When the control unit 11 detects that the power failure detection signal 231 has become active, it determines that a power failure has occurred, and during the backup time T (from time T2 to time T3) during which the control unit 11 can operate with the (c) second internal power supply 221 output from the power supply circuit 22, which is backed up by the power failure backup capacitor 24 and maintained until time T3, it transmits a power failure notification including power failure information and the time data 112 from the RTC 13 as the power failure time to the communication unit 210 of the communication destination with the highest priority after recovery from the power failure, and records the time data 112 from the RTC 13 as the power failure time. In addition, the time data is stored in, for example, a non-volatile memory in the control unit 11 so that it is not erased during and after the power failure.

[0056] When a power outage occurs in step S701 of FIG. 7 at the above timing, the power outage detection signal 231 can be generated in step S702 and the time of the power outage can be confirmed and stored.

[0057] As described above, according to the first embodiment, it is possible to provide a communication unit, a time recovery method, and a program that contribute to enabling the time of the clock function to be restored even during a long power outage, without requiring a power source to back up the clock function during a power outage.

[0058] [Second embodiment] Next, the second embodiment will be described in detail. In the first embodiment, the power system is identified using the power system ID, but the power system ID may be changed to area information created from a map in which the communication unit held by the worker is installed. Also, the communication unit with the highest priority after a power outage may be selected as a communication unit with different area information and the strongest electric field strength. For example, the area information may be displayed using one of the squares, with the map divided into n squares.

[0059] As described above, according to the second embodiment, as with the first embodiment, it is possible to provide a communication unit, a time recovery method, and a program that contribute to enabling the time of the clock function to be restored even during a long power outage, without requiring a power source to back up the clock function during a power outage.

[0060] Although each embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiments, and further modifications, substitutions, and adjustments can be made without departing from the basic technical idea of ​​the present invention. For example, the network configurations, element configurations, and message expression forms shown in the drawings are examples to help understand the present invention, and the present invention is not limited to the configurations shown in these drawings. In addition, "A and / or B" is used to mean at least either A or B.

[0061] Moreover, the procedures shown in the first and second embodiments can be realized by a program that causes a computer (9000 in FIG. 10) that functions as a communication unit or a control unit of a communication unit according to the present invention to realize the function as the communication unit or the control unit of the communication unit. Such a computer is exemplified by a configuration including a CPU (Central Processing Unit) 9010, a communication interface 9020, a memory 9030, and an auxiliary storage device 9040 in FIG. 10. That is, the CPU 9010 in FIG. 10 executes a control program for the communication unit or the control unit of the communication unit, and performs an update process for each calculation parameter held in the auxiliary storage device 9040 or the like.

[0062] The memory 9030 is a RAM (Random Access Memory), a ROM (Read Only Memory), or the like.

[0063] In other words, each part (processing means, function) of the communication unit or the control unit of the communication unit shown in the first and second embodiments described above can be realized by a computer program that causes the processor of the computer to execute each of the above-mentioned processes using its hardware.

[0064] Finally, preferred embodiments of the present invention will be summarized. [First form] The communication unit may be connected to the first power supply system and the network, and may include a control unit and a time management unit. The control unit of the communication unit may set a priority order for other communication units that are connected to a power supply system other than the first power supply system and that connect via the network after the first power supply system is restored from a power outage. The control unit of the communication unit may receive current time information from the other communication units via the network in accordance with the priority order after the first power supply system is restored from a power outage. The time management section of the communication unit may restore the time that is kept in accordance with the current time information. [Second Form] In the communication unit according to the first aspect, the control unit It is preferable that after the power outage of the first power system begins, a power outage notification is sent to the other communication unit, and after the first power system recovers from the power outage, the current time information is received from the other communication unit that sent the power outage notification. [Third Form] It is preferable that the communication unit according to the first or second aspect sets the priority order in accordance with the strength of the electric field strength of the other communication unit. [Fourth Form] In the communication unit according to the third aspect, it is preferable that the network is an ad-hoc network. [Fifth Form] In the communication unit according to the fourth aspect, it is preferable that the communication unit and the other communication unit are smart meters. [Sixth Form] The time recovery method may include a communication unit connected to a first power system and a network, which sets a priority of another communication unit connected to a power system other than the first power system and which connects via the network after the first power system is restored from a power outage. The time recovery method may include the communication unit receiving current time information from the other communication units via the network in accordance with the priority order after the first power system is restored from a power outage. The time restoration method may include restoring the time kept by the communication unit in accordance with the current time information. [7th form] A time restoration method according to a sixth aspect includes the steps of: transmitting a power outage notification to the other communication unit after the power outage of the first power system starts; It is preferable that, after the first power supply system recovers from a power outage, the current time information is received from the other communication unit that transmitted the power outage notification. [8th form] In the time recovery method according to the sixth or seventh aspect, it is preferable that the priority order is set in accordance with the strength of the electric field strength of the other communication units. [9th form] A program for causing a computer to execute the time recovery method according to the sixth or seventh aspect. [10th form] A program for causing a computer to execute the time recovery method according to the eighth aspect. The sixth and ninth forms can be expanded into the fourth and fifth forms, similarly to the first form.

[0065] The disclosure of Patent Document 1 is incorporated herein by reference. Within the framework of the entire disclosure of the present invention (including the scope of claims), and further based on the basic technical idea, modifications and adjustments of the embodiments and examples are possible. Furthermore, within the framework of the disclosure of the present invention, various combinations and selections of the various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. In other words, the present invention naturally includes various modifications and corrections that a person skilled in the art would be able to make according to the entire disclosure including the scope of claims and the technical idea. In particular, with regard to the numerical ranges described in this document, any numerical value or subrange included within the range should be construed as being specifically described even if not otherwise specified. Furthermore, the disclosures of the above cited documents, if necessary, in accordance with the spirit of the present invention, may be used in part or in whole in combination with the disclosures of this document as part of the disclosure of the present invention, and are deemed to be included in the disclosures of this application. [Explanation of symbols]

[0066] 10, 10C control blocks 11, 11C Control section 12 Radio circuit 13 Time Control Department (RTC) 14 Backup electric double layer capacitor 20 Power Block 21 AC / DC conversion circuit 22 Power supply circuit 23 Power failure detection circuit 24 Backup capacitor during power outage 30 Power outage detection block 40 Radio Block 100 Concentrator 111 External Data 112 Time Data 113 Wireless Data 200 Group A 210, 220, 330, 340, 350, 350C Communication Unit 212 Internal power supply 221 Second internal power supply 231 Power failure detection signal 215, 225, 335, 345, 355 Data collection device 290 A power supply system separate from the first power supply system 390 First Power System 300 Group B 400 Ad-hoc Network 500 Second Network 600 Collection Server 700 Radio Signal 1000 Communication Systems 1101 Field strength and power supply system ID record update section 1102 Connection destination determination unit 1103 Power outage information receiving and storage unit 1104 Power outage information and current time information transmission unit 1105 Time adjustment section 9000 Computers 9010 CPU 9020 Communication Interface 9030 Memory 9040 Auxiliary storage device

Claims

1. a control unit connected to the first power supply system and the network, and including a time management unit; The control unit is setting a priority order for other communication units connected to a power supply system other than the first power supply system, the communication units being connected via the network after the first power supply system is restored from a power outage; receiving current time information from the other communication units via the network in accordance with the priority order after the first power supply system is restored from a power outage; The time management unit, Restoring the time to be measured according to the current time information. Communications unit.

2. The control unit is After the power outage of the first power system starts, transmitting a power outage notification to the other communication unit; receiving the current time information from the other communication unit that transmitted the power outage notification after the first power supply system is restored from the power outage; 2. The communication unit of claim 1.

3. 3. The communication unit according to claim 1, wherein the priority order is set according to the strength of the electric field strength of the other communication units.

4. The communication unit of claim 3 , wherein the network is an ad-hoc network.

5. The communication unit according to claim 4 , wherein the communication unit and the other communication unit are smart meters.

6. connected to the first power supply system and the network; The communication unit setting a priority order for other communication units connected to a power supply system other than the first power supply system, the communication units being connected via the network after the first power supply system is restored from a power outage; receiving current time information from the other communication units via the network in accordance with the priority order after the first power supply system is restored from a power outage; Restoring the time to be measured according to the current time information. How to restore time.

7. After the power outage of the first power system starts, transmitting a power outage notification to the other communication unit; receiving the current time information from the other communication unit that transmitted the power outage notification after the first power supply system is restored from the power outage; The time restoration method according to claim 6.

8. 8. The time recovery method according to claim 6, wherein the priority order is set according to the strength of the electric field strength of the other communication units.

9. A program causing a computer to execute the time restoration method according to claim 6 or 7.

10. A program causing a computer to execute the time restoration method according to claim 8.

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