COMMUNICATION SYSTEM, COMMUNICATION CONTROL METHOD, AND PROGRAM

Abstract

The communication control device (1) has a message acquisition unit (111) that acquires a device message generated by the device (3) via the local network based on a connectionless communication protocol, and a transmission request unit (114) that transmits transmission request information to the device (3) requesting transmission of a device message from the device (3). The terminal device (4) has a message acquisition unit (414) that acquires device identification information response information generated by the device (3) via the local network, and stores the acquired device identification information response information in a message buffer (421) that can store all device identification information response information transmitted from the device (3) that is the destination of the device identification information request information. A communication system including this communication control device (1) can appropriately manage the device (3) connected to the local network.

Description

[Technical field]

[0001] The present disclosure relates to a communication system, a communication control method, and a program. [Background technology]

[0002] A home device management device has been proposed that manages ECHONET devices, which are devices compliant with the ECHONET (registered trademark) standard, via a network (see, for example, Patent Document 1). This home device management device periodically multicasts a request to acquire predetermined individual identification information that identifies the ECHONET device to the ECHONET devices connected to the network, receives individual identification information acquisition responses from each ECHONET device connected to the network, and manages the individual identification information included in the received individual identification information acquisition responses in association with the ECHONET addresses set in the ECHONET devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-172462 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when a home appliance management apparatus as described in Patent Document 1 is connected to the same LAN (Local Area Network) as an ECHONET device, a connectionless communication protocol such as UDP may be adopted as a communication protocol between the home appliance management apparatus and ECHONET, prioritizing communication speed. In this case, when multiple ECHONET devices are connected to the LAN, it is assumed that when the multiple ECHONET devices receive an individual identification information acquisition request at the same time, they transmit individual identification information acquisition responses to the home appliance management apparatus at the same time. In this case, if the home appliance management apparatus does not have a sufficient buffer function for temporarily storing the individual identification acquisition response, there is a risk that the individual identification acquisition response will be missed. In addition, when a connectionless communication protocol is adopted, the home appliance management apparatus does not confirm the acquisition of the individual identification acquisition response from the ECHONET device that is the sender of the individual identification acquisition response, so that the ECHONET device that is the subject of the missed response may be left unmanaged without managing the individual identification information.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a communication system, a communication control method, and a program that are capable of appropriately managing devices connected to a network. [Means for solving the problem]

[0006] In order to achieve the above object, the communication system according to the present disclosure includes: A server; A first communication control device connected to a local network to which a device is connected; Connected to the local network The second 2 communication control device, The server, a transmission request unit that generates device table request information that requests the first communication control device to transmit device identification information of the device; an information transmission unit that transmits the device table request information to the first communication control device, The first communication control device, an information acquisition unit that acquires the device table request information transmitted from the server; a transmission request unit that generates transmission request information that requests the device to transmit a device message when the device table request information is acquired; an acquisition request unit that, when the transmission request information is generated, transmits to the second communication control device acquisition request information requesting the second communication control device to acquire the device message transmitted from the device; The second communication control device is a message transmitting unit that transmits, when the second communication control device acquires the acquisition request information, transmission request information for requesting the device to transmit a device message to the device via the local network; a second message acquisition unit that acquires, via the local network, a device message generated by the device, and stores the acquired device message in a message buffer that can store at least all of identification number information, IP address information, and MAC address information included in each of the device messages transmitted from the device that is the destination of the transmission request information transmitted by the message transmission unit; an information transmission unit that transmits device information including the device message stored in the message buffer to the server; . Effect of the Invention

[0007] According to the present disclosure, a second message acquisition unit of a second communication control device acquires a device message generated by a device via a local network and stores the acquired device message in the message buffer. This allows all device messages transmitted from the device to be stored in the message buffer without omission, making it possible to appropriately manage devices connected to the local network. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a communication system according to a first embodiment of the present disclosure. [Diagram 2] FIG. 1 is a block diagram showing a hardware configuration of a communication system according to a first embodiment. [Diagram 3] FIG. 1 is a block diagram showing a functional configuration of a communication system according to a first embodiment. [Figure 4] FIG. 1 is a diagram showing an example of information stored in a device information storage unit of a cloud server according to the first embodiment; [Diagram 5] FIG. 1 is a sequence diagram showing an operation of a communication system according to a first embodiment. [Figure 6] FIG. 1 is a sequence diagram showing an operation of a communication system according to a first embodiment. [Figure 7] FIG. 1 is a sequence diagram showing an operation of a communication system according to a first embodiment. [Figure 8] FIG. 1 is a sequence diagram showing an operation of a communication system according to a first embodiment. [Figure 9] FIG. 1 is a sequence diagram showing an operation of a communication system according to a first embodiment. [Figure 10] FIG. 1 is a sequence diagram showing an operation of a communication system according to a first embodiment. [Figure 11]1 is a flowchart showing an example of a flow of a communication control process executed by a communication control device according to a first embodiment. [Figure 12] A flowchart showing an example of the flow of a communication control process executed by a terminal device according to the first embodiment. [Figure 13] 1 is a flowchart showing an example of the flow of a device control process executed by a cloud server according to the first embodiment. [Figure 14] FIG. 11 is a block diagram showing a functional configuration of a communication system according to a second embodiment of the present disclosure. [Figure 15] FIG. 11 is a sequence diagram showing an operation of a communication system according to a second embodiment. [Figure 16] FIG. 11 is a sequence diagram showing an operation of a communication system according to a second embodiment. [Figure 17] FIG. 11 is a sequence diagram showing an operation of a communication system according to a second embodiment. [Figure 18] 11 is a flowchart showing an example of a flow of a communication control process executed by a communication control device according to a second embodiment. [Figure 19] 11 is a flowchart showing an example of the flow of a device control process executed by a cloud server according to a second embodiment. [Figure 20] FIG. 11 is a block diagram showing a functional configuration of a communication system according to a third embodiment of the present disclosure. [Figure 21] FIG. 11 is a sequence diagram showing an operation of a communication system according to a third embodiment. [Figure 22] A flowchart showing an example of a flow of a communication control process executed by a communication control device according to a third embodiment. [Diagram 23] A flowchart showing an example of the flow of a communication control process executed by a cloud server according to a third embodiment. [Figure 24] FIG. 11 is a block diagram showing a functional configuration of a communication system according to a modified example. [Diagram 25] 11 is a flowchart showing an example of the flow of a device control process executed by a cloud server according to a modified example. [Figure 26] FIG. 11 is a block diagram showing a functional configuration of a communication system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment 1) A communication system according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings. The communication system according to the present embodiment includes a first communication control device connected to a local network to which a device is connected, and a second communication control device connected to the local network. The first communication control device includes a first message acquisition unit that acquires a device message generated by the device via the local network based on a connectionless communication protocol, a transmission request unit that transmits transmission request information to the device, which requests the device to transmit a device message, a transmission request determination unit that determines whether the transmission request information is multicast to the device, and an acquisition request unit that transmits acquisition request information to the second communication control device, which requests the second communication control device to acquire a device message transmitted from the device, when it is determined that the transmission request information is multicast to the device. The second communication control device also includes an acquisition request determination unit that determines whether the acquisition request information has been acquired, and a second message acquisition unit that acquires a device message generated by the device via the local network when it is determined that the acquisition request information has been acquired, and stores the acquired device message in a message buffer that can store all device messages transmitted from the device to which the transmission request information is transmitted.

[0010] As shown in Fig. 1, the communication system according to the present embodiment includes a cloud server 2, a device 3 installed in a house, a communication control device 1 that transmits device messages generated by the device 3 to the cloud server 2, and a terminal device 4. The device 3, the communication control device 1, and the terminal device 4 are capable of communicating with each other via a local network NW2 such as a wireless LAN (Local Area Network). The cloud server 2 is also capable of communicating with a wide area network NW1 such as the Internet and a broadband router (hereinafter referred to as "BBR") 8. The device 3 is, for example, an air conditioner equipped with a wireless module, and communicates with the BBR 8, the communication control device 1, and the terminal device 4 via the local network NW2.

[0011] The device 3 is, for example, an air conditioner equipped with a wireless module, and communicates with the communication control device 1 or the terminal device 4 via the local network NW2 using communication middleware such as ECHONETLite (registered trademark). Here, the device 3 communicates with the communication control device 1 and the terminal device 4 based on a connectionless communication protocol, for example, by a communication protocol that employs UDP as a transport layer. When the device 3 acquires device status request information that requests the cloud server 2 to transmit device status information indicating the device's status transmitted from the communication control device 1, the device 3 generates device status information including status parameter information indicating the device 3's status and transmits it to the communication control device 1. When the device 3 acquires device identification information request information from the communication control device 1 or the terminal device 4 that requests the device 3 to transmit device identification information that identifies the device, the device 3 generates device identification information response information including the device identification information described above in response to the request and transmits it to the communication control device 1. Here, the device identification information request information is information including identification number information that identifies the device 3 in the application layer, and is, for example, an instance list request message that requests the device 3 to transmit an instance list notification message in the communication protocol of the ECHONETLite standard. Furthermore, the identification number information is, for example, information indicating a 16-byte identification number assigned to each device 3 in the ECHONET Lite standard. The device identification information response information is information including the MAC address information and IP address information of the device 3, and is, for example, an instance list notification message transmitted by multicast from the device 3 in the communications protocol of the ECHONET Lite standard. Furthermore, the device 3 operates based on control information transmitted from the communications control device 1.

[0012] The communication control device 1 transmits a device message generated by the device 3 to the cloud server 2 via the wide area network NW1. As shown in FIG. 2, the communication control device 1 includes a CPU (Central Processing Unit) 101, a main memory unit 102, an auxiliary memory unit 103, a communication unit 106, and a bus 109 connecting each unit. The main memory unit 102 is a volatile memory such as a RAM (Random Access Memory) and is used as a working area for the CPU 101. The auxiliary memory unit 103 has a non-volatile memory such as a semiconductor memory, functions as a ROM (Read Only Memory) and storage, and stores programs for realizing various functions of the communication control device 1. The communication unit 106 has, for example, a wireless module, and performs wireless communication with the device 3 and the BBR 8.

[0013] 3, the CPU 101 functions as a message acquisition unit 111, an information transmission unit 112, an information acquisition unit 113, a transmission request unit 114, a transmission request determination unit 115, a message transmission unit 116, an acquisition request unit 117, and a multicast adoption availability information acquisition unit 118. The message acquisition unit 111 acquires a device message transmitted from the device 3, and notifies the information transmission unit 112 of the acquired device message and the IP address information of the sender of the device message. This device message is the above-mentioned device identification information response information or the above-mentioned device status information.

[0014] The information transmitting unit 112 encapsulates the device message acquired by the message acquiring unit 111 and transmits it to the cloud server 2. Here, the information transmitting unit 112 adds the MAC address information of the communication control device 1 to the device message, encapsulates it, adds header information for specifying the cloud server 2 as the destination, and transmits it to the cloud server 2. Here, the header information is, for example, information indicating the domain name of the cloud server 2.

[0015] When the information acquisition unit 113 acquires various information having the communication control device 1 as a destination from the cloud server 2, it extracts information including the MAC address information of the device 3 and the MAC address information of the communication control device 1 by removing header information from the acquired information and then decapsulating it. Here, the various information includes device status request information that requests the device 3 to transmit device status information indicating the status of the device 3, and control information for controlling the device 3. Then, the information acquisition unit 113 notifies the message transmission unit 116 of the extracted various information. Furthermore, when the information acquisition unit 113 acquires device table request information transmitted from the cloud server 2 that requests the communication control device 1 to transmit device identification information of the device 3, it notifies the transmission request unit 114 of the acquired device table request information.

[0016] When the multicast adoption availability information acquisition unit 118 acquires multicast adoption availability notification information or multicast adoption unavailable notification information transmitted from the terminal device 4, it notifies the transmission request unit 114 of the acquired various information. The transmission request unit 114 generates device identification information request information which is transmission request information requesting the device 3 to transmit the above-mentioned device identification information. Here, the transmission request unit 114 is set to one of a multicast mode in which the destination IP address of the device identification information request information is set to a multicast address, and a broadcast mode in which the destination IP address of the device identification information request information is set to a broadcast address. When the multicast adoption availability information is notified from the multicast adoption availability information acquisition unit 118, the transmission request unit 114 is set to the multicast mode, and when the multicast adoption unavailable notification information is notified from the multicast adoption availability information acquisition unit 118, the transmission request unit 114 is set to the broadcast mode.

[0017] The transmission request determination unit 115 determines whether the device identification information request information generated by the transmission request unit 114 is to be multicast or broadcast to the devices 3. If the destination IP address of the generated device identification information request information is set to a multicast address or a broadcast address, the transmission request determination unit 115 determines that the device identification information request information is to be multicast or broadcast to the devices 3. If the destination IP address of the generated device identification information request information is set to the IP address of one device 3, the transmission request determination unit 115 notifies the message sending unit 116 of the device identification information request information.

[0018] When it is determined that the device identification information request is to be multicast or broadcast to the devices 3, the acquisition request unit 117 transmits to the terminal device 4 acquisition request information requesting the terminal device 4 to acquire the device identification information transmitted from the device 3. The message sending unit 116 transmits the notified various information to the device 3 based on the IP address information of the device 3 included in the various information notified by the information acquiring unit 113. Furthermore, when the message sending unit 116 is notified of device identification information request information by the transmission request determining unit 115, it transmits the notified device identification information request to one device 3 identified by the IP address information based on the IP address information of the device 3 included in the notified device identification information request information.

[0019] When the terminal device 4 acquires the above-mentioned acquisition request information from the communication control device 1, the terminal device 4 transmits a device message generated by the device 3 to the cloud server 2 via the wide area network NW1. As shown in FIG. 2, the terminal device 4 includes a CPU 401, a main memory unit 402, an auxiliary memory unit 403, a wide area communication unit 406, a local communication unit 407, and a bus 409 connecting each unit. The main memory unit 402 is a volatile memory and is used as a work area for the CPU 401. The auxiliary memory unit 403 has a non-volatile memory and stores programs for realizing various functions of the terminal device 4. The display unit 404 is a display device such as a liquid crystal display or an organic EL (Electro-Luminescence) display. The input unit 405 is, for example, a transparent touch pad arranged on top of the display unit 404. The wide area communication unit 406 communicates with the cloud server 2 via the wide area network NW1. The local communication unit 407 has, for example, a wireless module and performs wireless communication with the device 3. In this embodiment, an example is described in which the terminal device 4 communicates with the cloud server 2 via a base station using the wide area communication unit 406, but this is not limited to the above. For example, the terminal device 4 may only have a local communication unit 407 and communicate with the cloud server 2 via the local communication unit 407, BBR8, and the wide area network NW1.

[0020] The CPU 401 loads the programs stored in the auxiliary storage unit 403 into the main storage unit 402 and executes them, thereby functioning as an acquisition request determination unit 411, a transmission request unit 412, a message transmission unit 413, a message acquisition unit 414, an information transmission unit 415, a reception unit 416, a multicast adoption availability notification unit 417, and a display control unit 418, as shown in Fig. 3. The main storage unit 402 shown in Fig. 2 also has a message buffer 421 shown in Fig. 3. The message buffer 421 has a storage capacity sufficient to store all device messages transmitted from all devices 3 that are destinations of device identification information request information.

[0021] The acquisition request determination unit 411 determines whether or not the acquisition request information transmitted from the communication control device 1 has been acquired. When the acquisition request determination unit 411 determines that the acquisition request information has been acquired, the transmission request unit 412 generates the above-mentioned device identification information request information in which the destination IP address is set to a multicast address or a broadcast address. When the transmission request unit 412 is notified of operation information indicating a network initial connection operation described later from the reception unit 416, the transmission request unit 412 generates device identification information request information in which the destination IP address is set to a multicast address and device identification information request information in which the destination IP address is set to a broadcast address. In this case, the transmission request unit 412 notifies the message transmission unit 413 and the message acquisition unit 414 of two types of creation notification information notifying that two types of device identification information request information with different destination IP addresses have been generated. The message transmission unit 413 transmits the generated device identification information request information by multicast or broadcast to the device 3 based on the setting content of the destination IP address. In addition, when the message sending unit 413 receives the above-mentioned two types of creation notification information from the transmission request unit 412, it sends device identification information request information with the destination IP address set to a multicast address, and then, after a preset waiting time has elapsed, sends another device identification information request information with the destination IP address set to a broadcast address.

[0022] When the message acquisition unit 414 acquires the device identification information response information transmitted from the device 3 in response to the above-mentioned device identification information request information, the message acquisition unit 414 extracts the identification number information and the IP address information and MAC address information of the sender of the device identification information response information included in the acquired device identification information response information, and stores the extracted identification number information, IP address information, and MAC address information in correspondence with each other in the message buffer 421. As a result, the message buffer 421 stores device table information that associates the identification number information, IP address information, and MAC address information with each other for each device 3 connected to the local network NW2. In addition, when the message acquisition unit 414 is notified of the above-mentioned two types of creation notification information from the transmission request unit 412, the message acquisition unit 414 acquires the device identification information response information corresponding to the device identification information request information in which the destination IP address is set to a multicast address, and then acquires the device identification information response information corresponding to the device identification information request information in which the destination IP address is set to a broadcast address after a preset waiting time has elapsed. Then, the message acquisition unit 414 stores the device identification information, IP address information, and MAC address information included in the device identification response information corresponding to the device identification information request information in which the acquired destination IP address is set to a multicast address, and the device identification information, IP address information, and MAC address information included in the device identification information response information corresponding to the device identification information request information in which the acquired destination IP address is set to a broadcast address, separately in the message buffer 421. As a result, the message buffer 421 stores the device table information corresponding to the device identification information request information in which the destination IP address is set to a multicast address, and the device table information corresponding to the device identification information request information in which the destination IP address is set to a broadcast address, separately.

[0023] The information transmitting unit 415 encapsulates the device table information stored in the message buffer 421 and transmits it to the cloud server 2. Here, the information transmitting unit 415 adds the MAC address information of the communication control device 1 to the device table information, encapsulates it, adds header information for specifying the cloud server 2 as the transmission destination, and transmits it to the cloud server 2.

[0024] The reception unit 416 receives the operation contents performed by the user of the terminal device 4 on the input unit 405, generates operation information according to the received operation contents, and notifies the transmission request unit 412. Assume that the user newly connects the device 3 to the local network NW2, and then performs a network initial connection operation on the input unit 405 to register a combination of the device identification information, IP address information, and MAC address information of the newly connected device 3 in the device table information managed by the cloud server 2. In this case, the reception unit 416 receives the network initial connection operation, generates operation information indicating the contents of the network initial connection operation, and notifies the transmission request unit 412. Based on the device table information stored in the message buffer 421, the display control unit 418 forms a device table display image indicating a combination of the identification number information, IP address information, and MAC address information of each device 3 indicated by the device table information, and causes the display unit 404 to display the image.

[0025] The multicast adoption possibility notifying unit 417 is a multicast adoption possibility determining unit that determines whether multicast transmission can be adopted as a method for transmitting device identification information request information based on a result of comparing the identification number information, IP address information, and MAC address information of the device 3 that is the transmission source of device identification information response information that can be obtained by multicasting device identification information request information to the device 3 with the identification number information, IP address information, and MAC address information of the device 3 that is the transmission source of device identification information response information that can be obtained by broadcasting device identification information request information to the device 3. Specifically, the multicast adoption possibility notifying unit 417 compares the device table information corresponding to the device identification information request information in which the destination IP address is set to the multicast address stored in the message buffer 421 with the device table information corresponding to the device identification information request information in which the destination IP address is set to the broadcast address, and determines whether the two match. If the device table information matches, the multicast adoption possibility notifying unit 417 transmits multicast adoption notification information to the communication control device 1 to notify that multicasting of device identification information is possible. On the other hand, if the device table information does not match, the multicast adoption possibility notifying unit 417 transmits multicast adoption impossible notification information to the communication control device 1 notifying that multicast of the device identification information is impossible.

[0026] Returning to FIG. 2, the cloud server 2 includes a CPU 201, a main memory unit 202, an auxiliary memory unit 203, a communication unit 206, a clock unit 207, and a bus 209 connecting the various units. The CPU 201 is, for example, a multi-core processor. The main memory unit 202 is a volatile memory and is used as a working area for the CPU 201. The auxiliary memory unit 203 has a non-volatile memory, functions as a ROM and storage, and stores programs for realizing various functions of the cloud server 2. The communication unit 206 communicates with the communication control device 1 via the wide area network NW1 and BBR8, and also communicates with the terminal device 4 via the wide area network NW1. The clock unit 207 has, for example, a real-time clock.

[0027] In the cloud server 2, the CPU 201 loads the program stored in the auxiliary storage unit 203 into the main storage unit 202 and executes it, thereby functioning as an information acquisition unit 211, a type determination unit 212, a device information update unit 213, a status acquisition unit 214, a control information generation unit 215, a transmission request unit 216, an information transmission unit 217, and an update necessity determination unit 218, as shown in FIG. 3. The auxiliary storage unit 203 shown in FIG. 2 also has a device information storage unit 231 and a status storage unit 232, as shown in FIG. 3. The device information storage unit 231 stores at least a combination of identification number information, MAC address information, and IP address information for identifying the device 3 in the application layer, in association with the IP address information of the communication control device 1 and the IP address information of the terminal device 4. The IP address information of the communication control device 1 and the IP address information of the terminal device 4 are device identification information for identifying the communication control device 1 and the terminal device 4, respectively. 4, the device information storage unit 231 stores device table information consisting of identification number information, MAC address information, and IP address information of each device 3 connected to the local network NW2 in association with the IP address information of the communication control device 1 connected to the local network NW2 and the IP address information of the terminal device 4. Here, the device table information is information in which the identification number information of each device 3 is associated with a combination of the MAC address information and IP address information of the device 3. The example shown in FIG. 4 indicates that the communication control device 1 assigned with the IP address "192.168.32.x0" and the terminal device 4 assigned with the IP address "192.168.32.x1" are connected to the local network NW2 indicated by the subnetwork information "192.168.32.0 / 24".

[0028] Returning to FIG. 3, the status storage unit 232 stores device status information indicating the status of the device 3 in association with the identification number information, MAC address information, and IP address information of the device 3.

[0029] When the information acquisition unit 211 acquires various pieces of information transmitted from the communication control device 1 or the terminal device 4, it notifies the type determination unit 212 of the acquired various pieces of information. The type determination unit 212 determines whether the information notified from the information acquisition unit 211 is device table information or device status information. Here, when the type determination unit 212 determines that the device message is device table information, it notifies the device information update unit 213 of the device table information. Furthermore, when the type determination unit 212 determines that the device message notified from the information acquisition unit 211 is the above-mentioned device status information, it notifies the status acquisition unit 214 of the device status information.

[0030] The device information update unit 213 updates the device table information stored in the device information storage unit 231 using the device table information notified from the type determination unit 212. The status acquisition unit 214 acquires device status information transmitted from the device 3 by transmitting, to the device 3, device status request information requesting the device 3 to transmit device status information. Specifically, the status acquisition unit 214 generates device status request information every time a preset device status acquisition time arrives, and notifies the information transmission unit 217 of the generated device status request information. Then, when the status acquisition unit 214 is notified of the device status information from the type determination unit 212, it updates the device status information stored in the status storage unit 232 using the notified device status information.

[0031] The control information generating unit 215 refers to the device status information stored in the status storage unit 232, and determines whether or not a control event has occurred that requires a change in the control content of the device 3, based on the state of the device 3 indicated by the device status information. Then, when the control information generating unit 215 determines that a control event has occurred, it generates control information for changing the control content of the device 3, and notifies the information transmitting unit 217 of the generated control information.

[0032] The transmission request unit 216 determines whether or not a preset device identification information acquisition time has arrived based on the time measured by the clock unit 207, and when it determines that the device identification information acquisition time has arrived, it generates the above-mentioned device table request information and notifies the information transmitting unit 217 of the generated device table request information. Furthermore, when the transmission request unit 216 is notified of update requirement notification information (described later) from the update necessity determination unit 218, it generates device table request information and notifies the information transmitting unit 217 of the generated device table request information.

[0033] When the information transmitting unit 217 is notified of various information from the state acquiring unit 214 and the control information generating unit 215, it specifies the communication control device 1 as the destination according to the notified various information. Here, the information transmitting unit 217 specifies the IP address information of the communication control device 1 associated with the combination of the MAC address information and the IP address information of the device 3 as the destination of the control information stored in the device information storage unit 231. Then, the information transmitting unit 217 encapsulates the notified various information and adds header information for specifying the identified communication control device 1 as the destination. Then, the information transmitting unit 217 transmits the encapsulated various information to the destination indicated by the identified IP address information. Also, when the information transmitting unit 217 is notified of the device table request information from the transmission request unit 216, it transmits the notified device table request information to the communication control device 1.

[0034] If the information acquisition unit 211 does not acquire the encapsulated device status information transmitted from the communication control device 1 within a preset allowable response time after the information transmission unit 217 transmits the encapsulated device status request information to the communication control device 1, the update necessity determination unit 218 determines that the device table information stored in the device information storage unit 231 needs to be updated. Here, if the device status information is not acquired within a preset waiting time after the update necessity determination unit 218 transmits the device status request information to the communication control device 1, the update necessity determination unit 218 notifies the information transmission unit 217 of retransmission request information requesting the information transmission unit 217 to retransmit the device status request information. This waiting time is set to, for example, 20 sec. Then, if the device status information is not acquired within the above-mentioned allowable response time even if the update necessity determination unit 218 repeatedly notifies the information transmission unit 217 of the retransmission request information every above-mentioned waiting time, the update necessity determination unit 218 determines that the device table information needs to be updated. Furthermore, after transmitting the encapsulated control information to the communication control device 1, if the state of the corresponding device 3 stored in the state storage unit 232 does not reflect the transmitted control information after the lapse of the overhead time required for the corresponding device 3 to change its state based on the control information, the update necessity determination unit 218 determines that the device table information needs to be updated. Then, when the update necessity determination unit 218 determines that the device table information needs to be updated, it notifies the transmission request unit 216 of update necessity notification information notifying that effect.

[0035] Next, the operation of the communication system according to the present embodiment will be described with reference to FIG. 5 to FIG. 9. Here, it is assumed that a process for establishing a connection has already been executed between the communication control device 1, the terminal device 4, and the cloud server 2, and that the communication control device 1, the terminal device 4, and the cloud server 2 have acquired each other's IP address information. First, as shown in FIG. 5, it is assumed that a user performs the above-mentioned network initial connection operation on the input unit 405 of the terminal device 4. In this case, the terminal device 4 generates device identification information request information in which the destination IP address is set to a multicast address (step S1). Next, the generated device identification information request information is multicast to the device 3 (step S2). On the other hand, when the device 3 acquires the device identification information request information, it generates device identification information response information including its own identification number information in response to the request (step S3). Next, the generated device identification information response information is transmitted from the device 3 to the terminal device 4 (step S4). On the other hand, when the terminal device 4 acquires the device identification information response information, it extracts the identification number information, IP address information, and MAC address information contained in the acquired device identification response information, and stores the extracted device identification information, IP address information, and MAC address information in the message buffer 421 in correspondence with each other (step S5).

[0036] Thereafter, after a preset waiting time has elapsed since the process of step S1 was executed, the terminal device 4 generates device identification information request information with the destination IP address set to the broadcast address (step S6). Next, the generated device identification information request information is broadcast to the device 3 (step S7). Meanwhile, upon receiving the device identification information request information, the device 3 generates device identification information response information including its own identification number information in response to the request (step S8). Next, the generated device identification information response information is transmitted from the device 3 to the terminal device 4 (step S9). Meanwhile, upon receiving the device identification information response information, the terminal device 4 extracts the device identification information, IP address information, and MAC address information included in the obtained device identification response information, and stores the extracted identification number information, IP address information, and MAC address information in the message buffer 421 in association with each other (step S10). Here, the terminal device 4 distinguishes between the identification number information, IP address information, and MAC address information contained in the device identification response information corresponding to the multicast device identification information request information, and the device identification information, IP address information, and MAC address information contained in the device identification information response information corresponding to the broadcast device identification information request information, and stores them in the message buffer 421. As a result, the message buffer 421 stores separately the device table information corresponding to the multicast device identification information request information and the device table information corresponding to the broadcast device identification information request information.

[0037] Next, the terminal device 4 forms a device table display image based on the device table information stored in the message buffer 421 and displays it on the display unit 404 (step S11). After that, it is assumed that the terminal device 4 determines that the device table information stored in the message buffer 421 corresponding to the multicast-transmitted device identification information request information matches the device table information corresponding to the broadcast-transmitted device identification information request information (step S12). In this case, as shown in FIG. 6, the above-mentioned multicast adoption possible notification information is transmitted from the terminal device 4 to the communication control device 1 (step S13). On the other hand, when the communication control device 1 acquires the multicast adoption possible notification information, it sets the transmission mode of the device identification information request information to the above-mentioned multicast mode in response to this (step S14). Next, either one of the device table information corresponding to the multicast-transmitted device identification information request information stored in the message buffer 421 and the device table information corresponding to the broadcast-transmitted device identification information request information is transmitted from the terminal device 4 to the cloud server 2 (step S15). On the other hand, when the cloud server 2 acquires the device table information transmitted from the terminal device 4, the cloud server 2 stores the acquired device table information in the device information storage unit 231 in association with the IP address information of the terminal device 4 (step S16).

[0038] Also, after the above-mentioned processes from step S1 to S11 are executed, as shown in FIG. 7, it is assumed that the terminal device 4 determines that the device table information corresponding to the multicast-transmitted device identification information request information stored in the message buffer 421 does not match the device table information corresponding to the broadcast-transmitted device identification information request information (step S17). In this case, the above-mentioned multicast adoption non-availability notification information is transmitted from the terminal device 4 to the communication control device 1 (step S18). Meanwhile, upon acquiring the multicast adoption non-availability notification information, the communication control device 1 sets the transmission mode of the device identification information request information to the broadcast mode in response to this (step S19). Subsequently, the device table information corresponding to the broadcast-transmitted device identification information request information stored in the message buffer 421 is transmitted from the terminal device 4 to the cloud server 2 (step S20). Meanwhile, upon acquiring the device table information transmitted from the terminal device 4, the cloud server 2 stores the acquired device table information in the device information storage unit 231 in association with the IP address information of the terminal device 4 (step S21).

[0039] Thereafter, when the preset device identification information acquisition time arrives, the cloud server 2 generates the above-mentioned device table request information (step S22), and the generated device table request information is transmitted from the cloud server 2 to the communication control device 1 (step S23). On the other hand, when the communication control device 1 acquires the device table request information, it generates device identification information request information in which the destination IP address is set to a multicast address or a broadcast address based on the set transmission mode in response to the device table request information (step S24). Next, the communication control device 1 determines that the destination IP address of the generated device identification information request information is a multicast address or a broadcast address (step S25), and the above-mentioned acquisition request information is transmitted from the communication control device 1 to the terminal device 4 (step S26). On the other hand, when the terminal device 4 acquires the acquisition request information, it generates device identification information request information in which the destination IP address is set to a multicast address or a broadcast address in response to the acquisition request information (step S27). Then, the generated device identification information request information is multicast transmitted or broadcast from the terminal device 4 to the device 3 (step S28).

[0040] On the other hand, when the device 3 acquires the device identification information request information, it generates device identification information response information including its own identification number information in response to the request (step S29). Thereafter, as shown in FIG. 8, the generated device identification information response information is transmitted from the device 3 to the terminal device 4 (step S30). On the other hand, when the terminal device 4 acquires the device identification information response information, it extracts the identification number information, IP address information, and MAC address information included in the acquired device identification response information, and stores the extracted identification number information, IP address information, and MAC address information in the message buffer 421 in association with each other (step S31). As a result, the terminal device 4 stores the device table information in the message buffer 421. Next, the device table information stored in the message buffer 421 is transmitted from the terminal device 4 to the cloud server 2 (step S32). On the other hand, when the cloud server 2 acquires the device table information transmitted from the terminal device 4, it stores the acquired device table information in the device information storage unit 231 in association with the IP address information of the terminal device 4 and the IP address information of the communication control device 1 (step S33).

[0041] Also, assume that a time for acquiring a device status indicating a preset device status of the device 3 has arrived. In this case, the cloud server 2 generates device status request information requesting the device 3 to transmit device status information (step S34). Next, the cloud server 2 identifies the IP address information of the communication control device 1 associated with the IP address information of the device 3 to which the device status request information is to be transmitted, which is stored in the device information storage unit 231. Then, the cloud server 2 executes an encapsulation process for adding header information including the identified IP address information to the device status request information (step S35). After that, the encapsulated device status request information is transmitted from the cloud server 2 to the communication control device 1 (step S36). On the other hand, when the communication control device 1 acquires the device status request information transmitted from the cloud server 2, it executes a decapsulation process for removing the header information from the acquired device status request information (step S37). Then, the device status information request information is transmitted from the communication control device 1 to the device 3 based on the MAC address information and IP address information of the device 3 included in the device status request information from which the header information has been removed (step S38).

[0042] On the other hand, when the device 3 acquires the device status request information, it generates device status information indicating its own status in response to the request (step S39). Next, the generated device status information is transmitted from the device 3 to the communication control device 1 (step S40). On the other hand, when the communication control device 1 acquires the device status information, it executes an encapsulation process of adding header information for specifying the cloud server 2 as the transmission destination to the acquired device status information (step S41). Next, the encapsulated device status information is transmitted from the communication control device 1 to the cloud server 2 (step S42). On the other hand, as shown in FIG. 9, when the cloud server 2 acquires the device status information transmitted from the communication control device 1, it updates the device status information stored in the status storage unit 232 by using the acquired device status information (step S43).

[0043] Furthermore, when the above-mentioned control event occurs, the cloud server 2 generates control information for changing the control content of the device 3 (step S44). Next, the cloud server 2 identifies the IP address information of the communication control device 1 associated with the IP address information of the device 3 to which the device status request information is to be transmitted, which is stored in the device information storage unit 231. Then, the cloud server 2 executes an encapsulation process for adding header information including the identified IP address information to the device status request information (step S45). Then, the encapsulated control information is transmitted from the cloud server 2 to the communication control device 1 (step S46). On the other hand, as shown in FIG. 7, when the communication control device 1 acquires the control information transmitted from the cloud server 2, it executes a decapsulation process for removing the header information from the acquired control information (step S47). Then, the control information is transmitted from the communication control device 1 to the device 3 based on the MAC address information and IP address information of the device 3 contained therein (step S48). On the other hand, when the device 3 acquires the control information, it operates based on the acquired control information (step S49).

[0044] Thereafter, it is assumed that an IP address update event occurs in which the IP address of the device 3 is updated. This IP address update event corresponds to, for example, a case in which the DHCP function unit of the BBR 8 sets a lease time for the IP address assigned to each device 3, and the IP address assigned to each device 3 is released after the set lease time has elapsed. In this case, the cloud server 2 determines that the device table information stored in the device information storage unit 231 needs to be updated (step S50). Here, the cloud server 2 determines that the device table information needs to be updated if, after transmitting device status request information to the communication control device 1, the cloud server 2 does not acquire device status information transmitted from the communication control device 1 within the above-mentioned allowable response time, or if, after transmitting control information to the communication control device 1, the status of the corresponding device 3 stored in the status storage unit 232 does not reflect the transmitted control information after the elapse of the overhead time of the corresponding device 3. In this case, the cloud server 2 generates the above-mentioned device table request information (step S22), and the generated device table request information is transmitted from the cloud server 2 to the communication control device 1 (step S23). On the other hand, when the communication control device 1 acquires the device table request information, it generates device identification information request information based on the set transmission mode in response to the device table request information (step S24). Next, the communication control device 1 determines that the destination IP address of the generated device identification information request information is a multicast address or a broadcast address (step S25), and the acquisition request information is transmitted from the communication control device 1 to the terminal device 4 (step S26), as shown in Fig. 10. Then, a series of processes from step S27 onwards are executed.

[0045] Next, the communication control process executed by the communication control device 1 according to the present embodiment will be described with reference to FIG. 11. This communication control process is started, for example, when the communication control device 1 is powered on and the communication control device 1 is placed in a location where it can be connected to the local network NW2. First, the multicast adoption availability information acquisition unit 118 judges whether or not it has acquired multicast adoption availability notification information transmitted from the terminal device 4 (step S101). Here, when the multicast adoption availability information acquisition unit 118 judges that it has acquired multicast adoption availability notification information (step S101: Yes), it notifies the transmission request unit 114 of the multicast adoption availability notification information. Then, after the transmission request unit 114 sets the transmission mode of the device identification request information to the multicast mode (step S102), the process of step S105 described later is executed. On the other hand, when the multicast adoption availability information acquisition unit 118 judges that it has not acquired multicast adoption availability notification information (step S101: No), it judges whether or not it has acquired multicast adoption unavailable notification information transmitted from the terminal device 4 (step S103). Here, if the multicast adoption availability information acquisition unit 118 determines that it has not acquired multicast adoption unavailable notification information (step S103: No), the process of step S105 described below is executed. On the other hand, if the multicast adoption availability information acquisition unit 118 determines that it has acquired multicast adoption unavailable notification information (step S103: Yes), it notifies the transmission request unit 114 of the multicast adoption unavailable notification information. Then, the transmission request unit 114 sets the transmission mode of the device identification request information to the broadcast mode (step S104).

[0046] Thereafter, the information acquisition unit 113 judges whether or not the above-mentioned device table request information transmitted from the cloud server 2 has been acquired (step S105). If the information acquisition unit 113 judges that the device table request information has not been acquired (step S105: No), the process of step S112 described later is executed. On the other hand, if the information acquisition unit 113 judges that the device table request information has been acquired (step S105: Yes), the transmission request unit 114 generates the above-mentioned device identification information request information based on the device table request information (step S106). Next, the transmission request determination unit 115 judges whether or not the destination IP address of the generated device identification information request information is set to a multicast address or a broadcast address (step S107). If the transmission request determination unit 115 judges that the destination IP address is an IP address assigned to one device 3 (step S107: No), the message transmission unit 116 transmits the generated device identification information request information to the device 3 to which the destination IP address has been assigned (step S108). As a result, the message acquisition unit 111 acquires device identification information response information transmitted from the device 3 that is the destination of the device identification information request information (step S109). Next, the message acquisition unit 111 extracts the device identification information, IP address information, and MAC address information contained in the acquired device identification information response information, and the information transmission unit 112 generates device information including these pieces of information and transmits it to the cloud server 2 (step S110). Then, the process of step S112 is executed.

[0047] On the other hand, it is assumed that the transmission request determination unit 115 determines that the destination IP address of the generated device identification information request information is set to a multicast address or a broadcast address (step S107: Yes). In this case, the acquisition request unit 117 transmits the above-mentioned acquisition request information to the terminal device 4 (step S111). Next, the message acquisition unit 111 determines whether or not the device status information transmitted from the device 3 has been acquired (step S112). Here, if the message acquisition unit 111 determines that the device status information has not been acquired (step S112: No), the process of step S114 described later is executed. On the other hand, if the message acquisition unit 111 determines that the device status information has been acquired (step S112: Yes), the message acquisition unit 111 performs an encapsulation process of adding header information for specifying the cloud server 2, including the MAC address information of the communication control device 1, as the destination to the acquired device status information, and then transmits the information to the cloud server 2 (step S113).

[0048] Next, the information acquisition unit 113 judges whether or not the device status request information or the control information transmitted from the cloud server 2 has been acquired (step S114). If the information acquisition unit 113 judges that the device status request information and the control information have not been acquired (step S114: No), the process of step S101 is executed again. On the other hand, if the information acquisition unit 113 judges that the device status request information or the control information has been acquired (step S114: Yes), the information acquisition unit 113 notifies the message sending unit 116 of the acquired device status request information or the control information. Then, the message sending unit 116 performs a decapsulation process to remove the header information from the device status request information or the control information notified from the information acquisition unit 113, and then transmits it to the device 3 (step S115). Thereafter, the process of step S101 is executed again.

[0049] Next, the communication control process executed by the terminal device 4 according to the present embodiment will be described with reference to FIG. 12. This communication control process is started, for example, when the terminal device 4 is powered on, a program for executing the communication control process is started in the terminal device 4, and the terminal device 4 is placed in a location where it can be connected to the local network NW2. First, the reception unit 416 judges whether or not the above-mentioned network initial connection operation performed by the user on the input unit 405 has been accepted (step S201). If the reception unit 416 judges that the network initial connection operation has not been accepted (step S201: No), the process of step S212 described later is executed. On the other hand, if the reception unit 416 judges that the network initial connection operation has been accepted (step S201: Yes), it generates operation information indicating the network initial connection operation and notifies the transmission request unit 412. Then, the transmission request unit 412 generates device identification information request information in which the destination IP address is set to a multicast address (step S202). Next, the message transmitting unit 413 transmits the generated device identification information request information to the device 3 by multicast (step S203). As a result, the message acquiring unit 414 acquires device identification information response information transmitted from the device 3 connected to the local network NW2 that is the transmission destination of the device identification information request information (step S204). Next, the message acquiring unit 111 extracts the device identification information, IP address information, and MAC address information contained in each of the acquired device identification information response information, and stores them in the message buffer 421 (step S205). As a result, the message buffer 421 stores device table information corresponding to the multicast transmitted device identification information request information. Thereafter, the transmission request unit 412 generates device identification information request information in which the destination IP address is set to the broadcast address (step S206), and the message transmitting unit 413 broadcasts the generated device identification information request information to the device 3 (step S207). As a result, the message acquisition unit 414 acquires the device identification information response information transmitted from the device 3 connected to the local network NW2, which is the destination of the device identification information request information (step S208).Next, the message acquisition unit 111 extracts the identification number information, IP address information, and MAC address information included in each of the acquired device identification information response information, and stores them in the message buffer 421 (step S209). As a result, the message buffer 421 stores device table information corresponding to the broadcasted device identification information request information.

[0050] Next, based on the device table information stored in the message buffer 421, the display control unit 418 forms a device table display image showing a combination of the identification number information, IP address information, and MAC address information of each device 3 indicated by the device table information, and displays it on the display unit 404 (step S210).

[0051] Thereafter, the multicast adoption availability notification unit 417 judges whether the device table information corresponding to the device identification information request information in which the destination IP address is set to the multicast address and the device table information corresponding to the device identification information request information in which the destination IP address is set to the broadcast address, stored in the message buffer 421, match (step S211). If the multicast adoption availability notification unit 417 judges that the device table information matches (step S211: Yes), it transmits the above-mentioned multicast adoption availability notification information to the communication control device 1 (step S212), and then the process of step S214 described later is executed. On the other hand, if the multicast adoption availability notification unit 417 judges that the device table information does not match (step S211: No), it transmits the above-mentioned multicast adoption unavailable notification information to the communication control device 1 (step S213). Then, the information transmission unit 415 transmits the device table information stored in the message buffer 421 to the cloud server 2 (step S214). Here, when multicast adoption possible notification information is transmitted to the communication control device 1, the information transmitting unit 415 transmits either the device table information corresponding to the multicast transmitted device identification information request information or the device table information corresponding to the broadcast transmitted device identification information request information stored in the message buffer 421 to the cloud server 2. On the other hand, when multicast adoption impossible notification information is transmitted to the communication control device 1, the information transmitting unit 415 transmits the device table information corresponding to the broadcast transmitted device identification information request information stored in the message buffer 421 to the cloud server 2.

[0052] Thereafter, the acquisition request determination unit 411 determines whether or not the aforementioned acquisition request information transmitted from the communication control device 1 has been acquired (step S215). Here, if the acquisition request determination unit 411 determines that the acquisition request information has not been acquired (step S215: No), the process of step S201 is executed again. On the other hand, if the acquisition request determination unit 411 determines that the acquisition request information has been acquired (step S215: Yes), the transmission request unit 412 generates the aforementioned device identification information request information (step S216). Here, the transmission request unit 412 sets the destination IP address to a multicast address or a broadcast address according to the determination result by the multicast adoption notification unit 417. Next, the message transmission unit 413 transmits the generated device identification information request information to the device 3 by multicast transmission or broadcast transmission (step S217). As a result, the message acquisition unit 414 acquires device identification information response information transmitted from all the devices 3 connected to the local network NW2 (step S218). Next, the message acquisition unit 111 extracts the device identification information, IP address information, and MAC address information contained in each of the acquired device identification information response information, and stores them in the message buffer 421 (step S219). As a result, the message buffer 421 stores device table information consisting of at least one combination of device identification information, IP address information, and MAC address information. Thereafter, the information transmission unit 415 transmits the device table information stored in the message buffer 421 to the cloud server 2 (step S220). Next, the process of step S201 is executed again.

[0053] Next, the device control process executed by the cloud server 2 according to the present embodiment will be described with reference to FIG. 13. This device control process is started, for example, when an application for executing the device control process is started in the cloud server 2. First, the transmission request unit 216 judges whether or not the above-mentioned device identification information acquisition time has arrived based on time information indicating the time measured by the clock unit 207 (step S301). Here, if the transmission request unit 216 judges that the device identification information acquisition time has arrived (step S301: Yes), the process of step S303 described later is executed. On the other hand, if the transmission request unit 216 judges that the device identification information acquisition time has not yet arrived (step S301: No), it judges whether or not the device table information needs to be updated (step S302). Here, if the transmission request unit 216 judges that the device table information does not need to be updated (step S302: No), the process of step S304 described later is executed. On the other hand, it judges whether or not the device table information needs to be updated. If the transmission request unit 216 determines that the device table information needs to be updated (step S302: Yes), it generates the above-mentioned device table request information and transmits it to the communication control device 1 (step S303).

[0054] Next, the control information generating unit 215 refers to the device status information stored in the status storage unit 232, and judges whether or not a control event that requires a change in the control content of the device 3 has occurred based on the state of the device 3 indicated by the device status information (step S304). If the control information generating unit 215 judges that a control event has not occurred (step S304: No), the process of step S307 described later is executed. On the other hand, if the control information generating unit 215 judges that a control event has occurred (step S304: Yes), it generates control information for changing the control content of the device 3 (step S305). Next, the information transmitting unit 217 identifies the IP address information of the communication control device 1 associated with the IP address information of the device 3 that is the destination of the device status request information stored in the device information storage unit 231, executes an encapsulation process of adding header information including the identified IP address information to the control information, and transmits the encapsulated control information to the communication control device 1 (step S306).

[0055] Thereafter, the status acquisition unit 214 judges whether the aforementioned device status acquisition time has arrived (step S307). If the status acquisition unit 214 judges that the device status acquisition time has not yet arrived (step S307: No), the process of step S310 described later is executed. On the other hand, if the status acquisition unit 214 judges that the device status acquisition time has arrived (step S307: Yes), the status acquisition unit 214 generates the aforementioned device status request information (step S308). Next, the information transmission unit 217 identifies the IP address information of the communication control device 1 associated with the IP address information of the device 3 to which the device status request information is to be transmitted, which is stored in the device information storage unit 231, performs an encapsulation process of adding header information including the identified IP address information to the device status request information, and transmits the encapsulated device status request information to the communication control device 1 (step S309).

[0056] Next, the information acquisition unit 211 determines whether or not various information transmitted from the communication control device 1 has been acquired (step S310). If the information acquisition unit 211 determines that various information transmitted from the communication control device 1 has not been acquired (step S310: No), the process of step S301 is executed again. On the other hand, if the information acquisition unit 211 determines that various information transmitted from the communication control device 1 has been acquired (step S310: No), it determines whether or not the acquired information is device table information (step S311).

[0057] Here, when the type determination unit 212 determines that the information is device table information (step S311: Yes), it notifies the device information update unit 213 of the device table information. Then, the device information update unit 213 uses the notified device table information to update the device table information stored in the device information storage unit 231 (step S312). Then, the process of step S301 is executed again. On the other hand, when the type determination unit 212 determines that the information is not device table information (step S311: No), it determines whether or not the acquired information is device status information (step S313). Here, when the type determination unit 212 determines that the information is not device status information (step S313: No), the process of step S301 is executed again. On the other hand, when the type determination unit 212 determines that the information is device status information (step S313: Yes), the status acquisition unit 214 uses the device status information to update the device status information of the device 3 stored in the status storage unit 232 (step S314). After that, the process of step S301 is executed again.

[0058] As described above, in the communication system according to the present embodiment, when the acquisition request unit 117 of the communication control device 1 determines that the device identification information request information is to be multicast to the device 3, it transmits the acquisition request information to the terminal device 4. Then, when the message acquisition unit 414 of the terminal device 4 determines that the above-mentioned acquisition request information has been acquired, it acquires the device identification information response information generated by the device 3 via the local network NW2, and stores a combination of the device identification information, IP address information, and MAC address information included in the acquired device identification information response information in the message buffer 421. This makes it possible to store all of the device identification information response information transmitted from the device 3 in response to the device identification information request information multicast to the device 3 in the message buffer 421, thereby making it possible to appropriately manage the devices 3 connected to the local network NW2.

[0059] However, when the multicast-transmitted device identification information request information is acquired at the same time by a plurality of devices 3 connected to the local network NW2, the plurality of devices 3 may transmit device identification information response information at the same timing. In this case, if the communication control device 1 has a low buffer capacity for device messages and has insufficient processing capacity when device messages arrive at the same time, there is a risk that the device identification information response information may be missed. For this reason, there is a risk that the number of devices 3 connected to the local network NW2 may have to be limited. In contrast, in the communication system according to the present embodiment, the terminal device 4 can store, in the message buffer 421, all of the device identification information response information transmitted from the devices 3 in response to the multicast-transmitted device identification information request information to the devices 3, so that the occurrence of problems due to missed reception of the device identification information response information can be suppressed.

[0060] Furthermore, in the terminal device 4 according to this embodiment, the display control unit 418 forms a device table display image showing a combination of the identification number information, IP address information, and MAC address information of each device 3 indicated by the device table information based on the device table information stored in the message buffer 421, and displays the image on the display unit 404. This allows the user to grasp the device table information corresponding to the device 3 connected to the local network NW2 by checking the device table display image, thereby improving convenience when the user performs maintenance on the device 3. In particular, this has the advantage that when the user replaces the BBR8 connected to the local network NW2, it becomes easier to grasp the connection status of the device 3 to the local network NW2 after the replacement.

[0061] Furthermore, in the communication system according to the present embodiment, simply by performing the above-mentioned initial network connection operation on input unit 405 of terminal device 4, device table information can be generated and stored in message buffer 421. As a result, even if the user cannot use wide area network NW1, it is possible to create in advance the device table information to be registered in cloud server 2, thereby improving the efficiency of the task of registering device table information in cloud server 2.

[0062] Incidentally, if the BBR8 complies with IGMP (Internet Group Management Protocol), when the device 3 is connected to the local network NW2, it is determined that the device 3 will join the multicast group of the BBR8 by transmitting a Membership Report message from the device 3 to the BBR. The BBR8 broadcasts a Query message to the devices 3 under its control, and receives a response message from the devices 3 belonging to the multicast group, thereby managing the devices 3 participating in the multicast group. On the other hand, the ECHONETLite uses "224.0.23.0" as the multicast address, but there are cases where the BBR8 that complies with IGMP or other switches connected to the BBR8 are set to block device messages whose destination IP address is set to the multicast address "224.0.23.0". In this case, the communication control device 1 may not be able to obtain device identification information response information from the devices 3 connected to the link through which the BBR8 or switch that blocks the multicast-transmitted device messages is interposed.

[0063] On the other hand, in the communication control device 1 according to the present embodiment, the multicast adoption possibility notifying unit 417 compares the identification number information, IP address information, and MAC address included in the device identification information response information that can be acquired by multicasting the device identification information request information to the device 3 with the identification number information, IP address information, and MAC address included in the device identification information response information that can be acquired by broadcasting the device identification information request information to the device 3. Then, the multicast adoption possibility notifying unit 417 determines whether or not multicast transmission can be adopted as a method for transmitting the device identification information request information based on the comparison result. Therefore, the communication control device 1 can appropriately manage the device 3 even if at least one device 3 is connected to a link including a BBR8 conforming to IGMP or another switch connected to the BBR8. Furthermore, when the transmission request unit 114 of the communication control device 1 acquires the multicast adoption possibility notifying information, it sets the transmission mode of the device identification information request information to the multicast mode with priority. This makes it possible to reduce the number of communication frames that are the device identification information request information sent to the local network NW2, and therefore the traffic in the local network NW2 can be reduced accordingly.

[0064] (Embodiment 2) The communication system of this embodiment differs from embodiment 1 in that the cloud server generates device identification information request information with the destination IP address set to a multicast address or broadcast address, performs the above-mentioned encapsulation process, and then transmits it to the communication control device.

[0065] The hardware configuration of the communication system according to this embodiment is the same as the hardware configuration described in the embodiment. Therefore, the hardware configuration of the communication system according to this embodiment will be described using the symbols shown in FIG. 2 as appropriate. As shown in FIG. 14, in the communication control device 2001 according to this embodiment, the CPU 101 loads a program stored in the auxiliary storage unit 103 into the main storage unit 102 and executes it, thereby functioning as a message acquisition unit 111, an information transmission unit 112, an information acquisition unit 2113, a transmission request determination unit 115, a message transmission unit 116, and an acquisition request unit 117. In FIG. 14, the same components as those in the first embodiment are denoted by the same symbols as those in FIG. 3.

[0066] When the information acquisition unit 2113 acquires the encapsulated device identification information request information from the cloud server 2002, the information acquisition unit 2113 removes the header information from the acquired device identification information request information and then decapsulates it. Then, the information acquisition unit 2113 notifies the transmission request determination unit 115 of the device identification information request information from which the header information has been removed. Then, the transmission request determination unit 115 determines whether the device identification information request information notified from the information acquisition unit 2113 is to be multicast or broadcast to the device 3.

[0067] In the terminal device 2004, the CPU 401 loads the programs stored in the auxiliary storage unit 403 into the main storage unit 402 and executes them to function as an acquisition request determination unit 411, a transmission request unit 412, a message transmission unit 413, a message acquisition unit 414, an information transmission unit 415, a reception unit 416, a multicast adoption notification unit 2417, and a display control unit 418. In addition, the main storage unit 402 has a message buffer 421.

[0068] The multicast adoption availability notifying unit 2417 judges whether the device table information corresponding to the device identification information request information in which the destination IP address is set to the multicast address and the device table information corresponding to the device identification information request information in which the destination IP address is set to the broadcast address, both stored in the message buffer 421, match. If the device table information matches, the multicast adoption availability notifying unit 2417 transmits the above-mentioned multicast adoption availability notification information to the cloud server 2002. On the other hand, if the device table information does not match, the multicast adoption availability notifying unit 2417 transmits the above-mentioned multicast adoption unavailable notification information to the cloud server 2002.

[0069] In the cloud server 2002, the CPU 201 loads the programs stored in the auxiliary storage unit 203 into the main storage unit 202 and executes them to function as an information acquisition unit 211, a type determination unit 212, a device information update unit 213, a status acquisition unit 214, a control information generation unit 215, a transmission request unit 2216, an information transmission unit 2217, an update necessity determination unit 218, and a multicast adoption information acquisition unit 2219. The auxiliary storage unit 203 also has a device information storage unit 231 and a status storage unit 232.

[0070] When the multicast adoption availability information acquisition unit 2219 acquires multicast adoption availability notification information or multicast adoption unavailable notification information transmitted from the terminal device 4, it notifies the transmission request unit 2216 of the acquired various information. The transmission request unit 2216 determines whether a preset device identification information acquisition time has arrived based on the time measured by the clock unit 207, and when it determines that the device identification information acquisition time has arrived, it generates device identification information request information and notifies the information transmission unit 2217 of the generated device identification information request information. Here, the transmission request unit 2216 is set to one of the above-mentioned multicast mode and broadcast mode. When the transmission request unit 2216 is notified of multicast adoption availability notification information from the multicast adoption availability information acquisition unit 2219, it sets the transmission mode to the multicast mode, and when the transmission request unit 2216 is notified of multicast adoption unavailable notification information from the multicast adoption availability information acquisition unit 2219, it sets the transmission mode to the broadcast mode. Furthermore, when update required notification information, which will be described later, is notified from update necessity determination unit 218, transmission request unit 2216 generates the above-mentioned device identification information request information and notifies information transmission unit 217 of the generated device identification information request information. Furthermore, transmission request unit 2216 notifies information transmission unit 2217 of subnet information indicating the subnet corresponding to the device table information to be updated, together with the device identification information request information.

[0071] When the information transmitting unit 2217 is notified of the device identification information request information and the subnet information from the transmission request unit 2216, it identifies the IP address information of the communication control device 1 corresponding to the notified subnet information. Then, the information transmitting unit 2217 encapsulates the notified device identification information request information by adding header information including the identified IP address information, and transmits the encapsulated device identification information request information to a destination indicated by the identified IP address information.

[0072] Next, the operation of the communication system according to the present embodiment will be described with reference to Figs. 15 to 17. In Figs. 15 to 17, the same processes as those in the first embodiment are denoted by the same reference numerals as those in Figs. 5 to 10. First, as shown in Fig. 15, it is assumed that the user performs the above-mentioned network initial connection operation on the input unit 405 of the terminal device 2004. In this case, a series of processes from steps S1 to S11 are executed. Thereafter, it is assumed that the terminal device 2004 determines that the device table information corresponding to the multicast-transmitted device identification information request information stored in the message buffer 421 matches the device table information corresponding to the broadcast-transmitted device identification information request information (step S12). In this case, the above-mentioned multicast adoptable notification information is transmitted from the terminal device 2004 to the cloud server 2002 (step S2001). On the other hand, when the cloud server 2002 acquires the multicast adoptable notification information, it sets the transmission mode of the device identification information request information to the multicast mode in response to the information (step S2002). Next, the processes from step S15 onwards described in the first embodiment are executed.

[0073] 16, after the above-mentioned processes from step S1 to S11 are executed, it is assumed that the terminal device 2004 determines that the device table information corresponding to the multicast-transmitted device identification information request information stored in the message buffer 421 does not match the device table information corresponding to the broadcast-transmitted device identification information request information (step S17). In this case, the above-mentioned multicast adoption non-available notification information is transmitted from the terminal device 2004 to the cloud server 2002 (step S2003). On the other hand, when the cloud server 2002 acquires the multicast adoption non-available notification information, the transmission mode of the device identification information request information is set to the broadcast mode in response thereto (step S2004). Next, the processes from step S20 described in the first embodiment are executed.

[0074] Furthermore, when the time for obtaining the device identification information arrives, the cloud server 2002 generates the device identification information request information (step S2005), and executes an encapsulation process for encapsulating the generated device identification information request information (step S2006), as shown in FIG. 17. Next, the encapsulated device identification information request information is transmitted from the cloud server 2002 to the communication control device 2001 (step S2007). On the other hand, when the communication control device 1 obtains the encapsulated device identification information request information, it executes a decapsulation process for removing header information from the obtained device identification information request information (step S2008). Next, when the communication control device 2001 determines that the destination IP address of the generated device identification information request information is a multicast address or a broadcast address (step S25), a series of processes from step S26 described in the first embodiment are executed.

[0075] Next, the communication control process executed by the communication control device 2001 according to this embodiment will be described with reference to FIG. 18. In FIG. 18, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG. 11. First, the information acquisition unit 2113 judges whether or not the above-mentioned device identification information request information transmitted from the cloud server 2 has been acquired (step S2101). If the information acquisition unit 2113 judges that the device identification information request information has not been acquired (step S2101: No), the process of step S112 is executed. On the other hand, if the information acquisition unit 2113 judges that the device identification information request information has been acquired (step S2101: Yes), the decapsulation process is executed to remove the header information from the acquired device identification information request information (step S2102). Next, the transmission request determination unit 115 judges whether or not the destination IP address of the device identification information request information from which the header information has been removed is set to a multicast address or a broadcast address (step S107). Here, if the transmission request determination unit 115 determines that the destination IP address is an IP address assigned to one device 3 (step S107: No), a series of processes from step S108 onwards are executed. On the other hand, it is assumed that the transmission request determination unit 115 determines that the destination IP address of the device identification information request information from which the header information has been removed is set to a multicast address or a broadcast address (step S107: Yes). In this case, the acquisition request unit 117 transmits the above-mentioned acquisition request information to the terminal device 4 (step S111), and then a series of processes from step S112 onwards are executed.

[0076] Next, the device control process executed by the cloud server 2002 according to this embodiment will be described with reference to FIG. 19. In FIG. 19, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG. 13. First, the multicast adoption availability information acquisition unit 2219 judges whether or not it has acquired multicast adoption availability notification information transmitted from the terminal device 2004 (step S2301). Here, when it is judged that it has acquired multicast adoption availability notification information (step S2301: Yes), it notifies the transmission request unit 2216 of the multicast adoption availability notification information. Then, after the transmission request unit 2216 sets the transmission mode of the device identification request information to the multicast mode (step S2302), the process of step S301 described later is executed. On the other hand, when it is judged that it has not acquired multicast adoption availability notification information (step S2301: No), the multicast adoption availability information acquisition unit 2219 judges whether or not it has acquired multicast adoption unavailable notification information transmitted from the terminal device 2004 (step S2303). If the multicast adoption availability information acquisition unit 2219 determines that it has not acquired multicast adoption unavailable notification information (step S2303: No), the process of step S301 described below is executed. On the other hand, if the multicast adoption availability information acquisition unit 2219 determines that it has acquired multicast adoption unavailable notification information (step S2303: Yes), it notifies the transmission request unit 2216 of the multicast adoption unavailable notification information. Then, the transmission request unit 2216 sets the transmission mode of the device identification request information to the broadcast mode (step S2304).

[0077] Thereafter, the transmission request unit 216 judges whether the time for obtaining the device identification information described above has arrived based on the time information indicating the time measured by the timer unit 207 (step S301). If the transmission request unit 216 judges that the time for obtaining the device identification information has arrived (step S301: Yes), the process of step S2305 described below is executed. On the other hand, if the transmission request unit 216 judges that the time for obtaining the device identification information has not yet arrived (step S301: No), the transmission request unit 216 judges whether the device table information needs to be updated (step S302: No). If the transmission request unit 216 judges that the device table information does not need to be updated (step S302: No), the process of step S304 described below is executed. On the other hand, the transmission request unit 216 judges whether the device table information needs to be updated. If the transmission request unit 2216 judges that the device table information needs to be updated (step S302: Yes), the transmission request unit 2216 generates the above-mentioned device identification information request information (step S2305). Then, the transmission request unit 2216 notifies the information transmitting unit 2217 of the subnet information corresponding to the device table information to be updated together with the device identification information request information. Next, the information transmitting unit 2217 identifies the IP address information of the communication control device 1 corresponding to the subnet information notified from the transmission request unit 2216, performs an encapsulation process of adding header information including the identified IP address information to the above-mentioned device identification information request information, and transmits the encapsulated device identification information request information to the communication control device 1 indicated by the identified IP address information (step S2306). Then, a series of processes from step S304 onwards are executed.

[0078] As described above, according to the communication system of the present embodiment, it is not necessary for communication control device 1 to generate device identification information request information, and therefore the configuration of communication control device 1 can be simplified accordingly.

[0079] (Embodiment 3) The communication system according to the present embodiment differs from the first embodiment in that device identification information request information is transmitted to the device only when the user performs the above-mentioned network initial connection operation on the input unit of the terminal device. The hardware configuration of the communication system according to the present embodiment is the same as the hardware configuration described in the embodiment. Therefore, the communication system hardware configuration according to the present embodiment will be described using the symbols shown in FIG. 2 as appropriate. As shown in FIG. 20, in the communication control device 3001 according to the present embodiment, the CPU 101 loads a program stored in the auxiliary storage unit 103 into the main storage unit 102 and executes it, thereby functioning as the message acquisition unit 111, the information transmission unit 112, the information acquisition unit 113, the transmission request unit 114, and the message transmission unit 116. In FIG. 20, the same components as those in the first embodiment are denoted by the same symbols as those in FIG. 3. The communication control device 3001 according to the present embodiment differs from the communication control device 1 according to the first embodiment in that it does not include the transmission request determination unit 115, the acquisition request unit 117, and the multicast adoption information acquisition unit 118.

[0080] In the terminal device 3004, the CPU 401 loads the program stored in the auxiliary storage unit 403 into the main storage unit 402 and executes it, thereby functioning as a transmission request unit 3412, a message transmission unit 3413, a message acquisition unit 414, an information transmission unit 415, a reception unit 416, and a display control unit 418. The main storage unit 402 also has a message buffer 421. When the transmission request unit 3412 is notified of operation information indicating the above-mentioned network initial connection operation from the reception unit 416, the transmission request unit 3412 generates device identification information request information in which the destination IP address is set to a multicast address or a broadcast address. Here, the destination IP address is set to a multicast address or a broadcast address depending on the operation content of the IP address setting operation performed by the user on the input unit 405. The message transmission unit 3413 transmits the generated device identification information request information by multicast or broadcast to the device 3 based on the setting content of the destination IP address.

[0081] Next, the operation of the communication system according to the present embodiment will be described with reference to FIG. 21. First, it is assumed that the user performs the above-mentioned network initial connection operation on the input unit 405 of the terminal device 3004. At this time, the user also performs an operation to select whether to perform multicast transmission or broadcast transmission when transmitting device identification information request information to the device 3. In this case, the terminal device 3004 generates device identification information request information in which the destination IP address is set to a multicast address or a broadcast address according to the user's selection (step S3001). Next, the generated device identification information request information is transmitted by multicast transmission or broadcast transmission from the terminal device 3004 to the device 3 (step S3002). On the other hand, when the device 3 acquires the device identification information request information, it generates device identification information response information including its own identification number information in response to the request information (step S3). Next, the generated device identification information response information is transmitted from the device 3 to the terminal device 3004 (step S4). On the other hand, when the terminal device 4 acquires the device identification information response information, it extracts the identification number information, IP address information, and MAC address information contained in the acquired device identification response information, and stores the extracted identification number information, IP address information, and MAC address information in the message buffer 421 in correspondence with each other (step S5).

[0082] Thereafter, either one of the device table information stored in message buffer 421 corresponding to the multicast transmitted device identification information request information and the device table information corresponding to the broadcast transmitted device identification information request information is transmitted from terminal device 3004 to cloud server 2 (step S15). On the other hand, upon acquiring the device table information transmitted from terminal device 4, cloud server 2 stores the acquired device table information in device information storage unit 231 in association with the IP address information of terminal device 4 (step S16). Then, when the time arrives for acquiring a device status indicating the preset device status of device 3, a series of processes from step S34 onwards described in embodiment 1 are executed.

[0083] The communication control device 3001 according to this embodiment executes a series of processes from steps S112 to S115 as shown in Fig. 22. In Fig. 22, the same processes as those in the first embodiment are denoted by the same reference numerals as in Fig. 11. After the message sending unit 116 performs a decapsulation process to remove header information from the device status request information or control information notified by the information acquiring unit 113 and transmits the information to the device 3 (step S115), the process of step S112 is executed again.

[0084] Next, the communication control process executed by the terminal device 4 according to this embodiment will be described with reference to FIG. 23. In FIG. 23, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG. 12. First, the process of step S201 is executed. When the reception unit 416 determines that the network initial connection operation has been received (step S201: Yes), the reception unit 3412 generates operation information indicating the network initial connection operation and notifies the transmission request unit 3412 of the operation information. Then, the transmission request unit 3412 generates device identification information request information in which the destination IP address is set to the multicast address or broadcast address selected by the user based on the operation information (step S3201). Next, the message transmission unit 3413 transmits the generated device identification information request information to the device 3 by multicast or broadcast (step S3203). As a result, the message acquisition unit 414 acquires device identification information response information transmitted from the device 3 connected to the local network NW2 and to which the device identification information request information is to be transmitted (step S204). Next, the message acquisition unit 111 extracts the device identification information, IP address information, and MAC address information included in each of the acquired device identification information response information, and stores them in the message buffer 421 (step S205). As a result, the message buffer 421 stores the device table information corresponding to the device identification information request information transmitted by multicast. After that, the display control unit 418 forms a device table display image showing a combination of the identification number information, IP address information, and MAC address information of each device 3 indicated by the device table information based on the device table information stored in the message buffer 421, and displays it on the display unit 404 (step S210). Next, the information transmission unit 415 transmits the device table information stored in the message buffer 421 to the cloud server 2 (step S214). Then, the process of step S201 is executed again.

[0085] As described above, according to this embodiment, the device identification information response information transmitted from the device 3 in response to the device identification information request information transmitted by multicast to the device 3 can be stored without omission in the message buffer 421 of the terminal device 3004, so that the devices 3 connected to the local network NW2 can be appropriately managed.

[0086] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments. For example, the terminal device 4, 2004 may generate both device identification information request information in which the destination IP address is set to a multicast address or broadcast address compatible with IPv4, and device identification information request information in which the destination IP address is set to a multicast address or broadcast address compatible with IPv6. In this case, the terminal device 4, 2004 may obtain device identification information response information including IP address information indicating an IP address compatible with IPv4 assigned to the device 3 from the device 3, and device identification information response information including IP address information indicating an IP address compatible with IPv6 assigned to the device 3 from the device 3. Then, the terminal device 4, 2004 may store device table information including the IP address information compatible with IPv4 of the device 3 and device table information including the IP address information compatible with IPv6 of the device 3 in the message buffer 421. In addition, the terminal device 4, 2004 may have an internet layer protocol determination unit (not shown) that determines whether each device 3 supports either or both of the internet layer protocols IPv4 and IPv6 by referring to device table information stored in the message buffer 421, the device table information including IP address information of the device 3 compatible with IPv4, and the device table information including IP address information of the device 3 compatible with IPv6.

[0087] According to this configuration, even if the internet layer protocols corresponding to the devices 3 are different from each other, it is possible to obtain a combination of the identification number information, IP address information, and MAC address information of each device 3 without omission. Therefore, it becomes possible to appropriately manage the devices 3.

[0088] In embodiment 2, when the cloud server determines that the device identification information request should be multicast or broadcast to device 3, it may send acquisition request information directly to the terminal device, requesting the terminal device to acquire the device identification information transmitted from device 3.

[0089] As shown in Fig. 24, in the communication control device 4001 according to this modification, the CPU 101 loads a program stored in the auxiliary storage unit 103 into the main storage unit 102 and executes it, thereby functioning as the message acquisition unit 111, the information transmission unit 112, the information acquisition unit 4113, the message transmission unit 116, and the acquisition request unit 117. In Fig. 24, the same components as those in the first and second embodiments are given the same reference numerals as those in Figs. 3 and 14. When the information acquisition unit 4113 acquires the encapsulated device identification information request information from the cloud server 4002, it removes the header information from the acquired device identification information request information and then decapsulates it. Then, the information acquisition unit 4113 notifies the message transmission unit 116 of the device identification information request information from which the header information has been removed.

[0090] In the terminal device 4004, the CPU 401 loads the program stored in the auxiliary storage unit 403 into the main storage unit 402 and executes it, thereby functioning as an acquisition request determination unit 4411, a transmission request unit 412, a message transmission unit 413, a message acquisition unit 414, an information transmission unit 415, a reception unit 416, a multicast adoption availability notification unit 2417, and a display control unit 418. The main storage unit 402 also has a message buffer 421. The acquisition request determination unit 4411 determines whether or not acquisition request information transmitted from the cloud server 4002 has been acquired, and when the transmission request unit 412 determines that the acquisition request information has been acquired by the acquisition request determination unit 4411, it generates the above-mentioned device identification information request information in which the destination IP address is set to a multicast address or a broadcast address.

[0091] In the cloud server 4002, the CPU 201 loads the program stored in the auxiliary storage unit 203 into the main storage unit 202 and executes it, thereby functioning as an information acquisition unit 211, a type determination unit 212, a device information update unit 213, a status acquisition unit 214, a control information generation unit 215, a transmission request unit 4216, an information transmission unit 2217, an update necessity determination unit 218, a multicast adoption information acquisition unit 2219, and an acquisition request unit 4220. The auxiliary storage unit 203 also has a device information storage unit 231 and a status storage unit 232. The transmission request unit 4216 determines whether a preset device identification information acquisition time has arrived based on the time measured by the clock unit 207, and when it determines that the device identification information acquisition time has arrived, it generates device identification information request information and notifies the information transmission unit 2217 of the generated device identification information request information. Here, the transmission request unit 4216 sets the transmission mode to the multicast mode when multicast adoption possible notification information is notified from the multicast adoption possible information acquisition unit 2219, and sets the transmission mode to the broadcast mode when multicast adoption impossible notification information is notified from the multicast adoption possible information acquisition unit 2219. When the transmission request unit 4216 sets the transmission mode to the multicast mode or broadcast mode, the acquisition request unit 4220 transmits the above-mentioned acquisition request information to the terminal device 4004.

[0092] As shown in Fig. 25, after a series of processes from step S2301 to S2304 are executed, if the transmission request unit 216 determines that the time to obtain the device identification information has arrived (step S301: Yes), or if the transmission request unit 4216 determines that the time to obtain the device identification information has not yet arrived (step S301: No) and that the device table information needs to be updated (step S302: Yes), the cloud server 4002 according to this modification generates the above-mentioned device identification information request information (step S2305). Next, the information transmission unit 2217 specifies the IP address information of the communication control device 1 corresponding to the subnet information notified from the transmission request unit 4216, executes an encapsulation process of adding header information including the specified IP address information to the above-mentioned device identification information request information, and transmits the encapsulated device identification information request information to the communication control device 1 indicated by the specified IP address information (step S2306). Then, the transmission request unit 4216 transmits the above-mentioned acquisition request information to the terminal device 4004 (step S4301). Then, a series of processes from step S304 onwards are executed.

[0093] According to this configuration, the above-mentioned acquisition request information is transmitted directly from the cloud server 4002 to the terminal device 4004, eliminating the need for the communication control device 4001 to perform processing for transmitting the acquisition request information to the terminal device 4004. This reduces the processing load on the communication control device 4001.

[0094] In the second embodiment, when the cloud server determines that the device identification information request is to be multicast or broadcast to the device 3, the cloud server may transmit to the terminal device acquisition instruction information instructing the terminal device to acquire the acquisition request information transmitted from the communication control device 2001. Then, only when the terminal device acquires the acquisition instruction information, the terminal device may be in a state where it is connected to the local network NW2 and is capable of acquiring the acquisition request information transmitted from the communication control device 2001 in response to the acquisition instruction information.

[0095] As shown in FIG. 26, in the terminal device 5004 according to this modification, the CPU 401 loads the program stored in the auxiliary storage unit 403 into the main storage unit 402 and executes it, thereby functioning as an acquisition request determination unit 411, a transmission request unit 412, a message transmission unit 413, a message acquisition unit 414, an information transmission unit 415, a reception unit 416, a multicast adoption availability notification unit 2417, a display control unit 418, and a terminal connection unit 5440. In FIG. 26, the same components as those in the first and second embodiments are given the same reference numerals as those in FIG. 3 and FIG. 14. Only when the terminal connection unit 5440 acquires acquisition instruction information transmitted from the cloud server 5002, the terminal connection unit 5440 makes the terminal device 5004 connected to the local network NW2, and the acquisition request determination unit 411 makes it possible to acquire acquisition request information transmitted from the communication control device 2001. Here, the terminal connection unit 5440 discards information other than the above-mentioned acquisition request information transmitted from the communication control device 2001.

[0096] In the cloud server 5002, the CPU 201 loads the program stored in the auxiliary storage unit 203 into the main storage unit 202 and executes it, thereby functioning as the information acquisition unit 211, the type determination unit 212, the device information update unit 213, the status acquisition unit 214, the control information generation unit 215, the transmission request unit 2216, the information transmission unit 5217, the update necessity determination unit 218, and the multicast adoption information acquisition unit 2219. The auxiliary storage unit 203 also has a device information storage unit 231 and a status storage unit 232. When the device identification information request information is transmitted by multicast transmission or broadcast transmission, the information transmission unit 5217 transmits the above-mentioned acquisition instruction information to the terminal device 5004. The information transmission unit 5217 also encapsulates the device identification information request information notified by the transmission request unit 2216 by adding header information, and transmits the encapsulated device identification information request information to a destination indicated by the IP address information included in the header information.

[0097] According to this configuration, the transmission of the aforementioned acquisition request information from the communication control device 2001 to the terminal device 5004 is controlled by the acquisition instruction information transmitted from the cloud server 5002 to the terminal device 5004, which has the advantage that it becomes easier for the cloud server 5002 to manage the traffic of the local network NW2.

[0098] In each embodiment, the terminal device 4, 2004, 3004, 4004, 5004 may be connected to or disconnected from the local network NW2 depending on the communication status between the device 3 and the communication control device 1, 2001, 3001, 4001. For example, the communication control device 1, 2001, 3001, 4001 may monitor the traffic with the device 3 and transmit communication volume information indicating the communication volume to the cloud server 2, 2002, 4002, 5002. Also, the cloud server 2, 2002, 4002, 5002 may transfer the communication volume information to the terminal device 4, 2004, 3004, 4004, 5004. When the communication volume indicated by the communication volume information acquired from the cloud servers 2, 2002, 4002, 5002 becomes larger than a preset reference communication volume, the terminal devices 4, 2004, 3004, 4004 may be configured to connect to the local network NW2 to back up the communication control devices 1, 2001, 3001, 4001, and when the communication volume falls below the reference communication volume, the terminal devices 4, 2004, 3004, 4004 may be configured to disconnect from the local network NW2.

[0099] In each embodiment, an example has been described in which the communication system includes terminal devices 4, 2004, but this is not limited to this, and instead of the terminal devices 4, 2004, a personal computer or a local server having communication capabilities connected to the local network NW2 may be used.

[0100] In the first embodiment, an example has been described in which the transmission request determination unit 115 determines whether the device identification information request information is multicast or broadcast to the device 3, and when it is determined that the device identification information request information is multicast or broadcast, the acquisition request unit 117 transmits the acquisition request information to the terminal device 4. However, the present invention is not limited to this, and for example, the transmission request determination unit 115 may determine whether the size of the device telegram corresponding to the transmission request information is equal to or larger than a preset reference telegram size. In this case, when it is determined that the size of the device telegram corresponding to the transmission request information is equal to or larger than the reference telegram size, the acquisition request unit 117 may transmit the above-mentioned acquisition request information to the terminal device 4. Then, when it is determined that the telegram acquisition unit 414 of the terminal device 4 has acquired the acquisition request information, it may acquire the device telegram generated by the device 3 via the local network NW2, and store the acquired device telegram in the telegram buffer 421. Here, the telegram buffer 421 may have a storage capacity capable of storing a device telegram having a size equal to or larger than the reference telegram size.

[0101] In each embodiment, an example has been described in which the device information storage unit 231 stores the IP address information and MAC address information of the device 3 in association with the identification number information unique to the device 3. However, this is not limiting, and the device information storage unit 231 may store the IP address information and MAC address information of the device 3 in association with model name information indicating the model name of the device 3, serial number information indicating the serial number of the device 3, and the like.

[0102] In addition, the various functions of the communication control devices 1, 2001, 3001, 4001, cloud servers 2, 2002, 4002, 5002, and terminal devices 4, 2004, 3004, 4004, 5004 according to the present disclosure may be realized by software, firmware, or a combination of software and firmware. In this case, the software or firmware may be written as a program, and the program may be stored and distributed in a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a DVD (Digital Versatile Disc), an MO (Magneto-Optical Disc), or a flash memory, and the program may be read and installed in a computer to configure a computer capable of realizing each of the above-mentioned functions. In addition, when each function is realized by sharing the work between an OS (Operating System) and an application, or by cooperation between the OS and an application, only the parts other than the OS may be stored in the recording medium.

[0103] Furthermore, each program may be superimposed on a carrier wave and distributed via a communication network. For example, the program may be posted on a bulletin board (BBS, Bulletin Board System) on the communication network and distributed via the network. These programs may then be started and executed under the control of the OS in the same way as other application programs, thereby enabling the above-mentioned processing to be performed.

[0104] Various embodiments and modifications of the present disclosure are possible without departing from the broad spirit and scope of the present disclosure. The above-described embodiments are for explaining the present disclosure and do not limit the scope of the present disclosure. In other words, the scope of the present disclosure is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the disclosure equivalent thereto are considered to be within the scope of the present disclosure. [Industrial Applicability]

[0105] The present disclosure is suitable as a system for managing multiple devices installed in a home. [Explanation of symbols]

[0106] 1,2001,3001,4001 Communication control device, 2,2002,4002,5002 Cloud server, 3 Device, 4,2004,3004,4004,5004 Terminal device, 8 BBR, 101,201,401 CPU, 102,202,402 Main memory, 103,203,403 Auxiliary memory, 106,206 Communication unit, 109,209,409 Bus, 111,414 Message acquisition unit, 112,217,415,2217,5217 Information transmission unit, 113,211,2113,4113 Information acquisition unit, 114,216,412,2216,3412,4216 Transmission request unit, 115 Transmission request determination unit, 116, 413, 3413 Message transmission unit, 117, 4220 Acquisition request unit, 118, 2219 Multicast adoption availability information acquisition unit, 207 Timekeeping unit, 212 Type determination unit, 213 Device information update unit, 214 Status acquisition unit, 215 Control information generation unit, 218 Update necessity determination unit, 231 Device information storage unit, 232 Status storage unit, 404 Display unit, 405 Input unit, 406 Wide area communication unit, 407 Local communication unit, 411, 4411 Acquisition request determination unit, 416 Reception unit, 417, 2417 Multicast adoption availability notification unit, 418 Display control unit, 421 Message buffer, 5440 Terminal connection unit, NW1 Wide area network, NW2 Local network

Claims

1. a first communication control device connected to a local network to which devices are connected; a second communication control device different from the first communication control device and connected to the local network; The first communication control device a first message acquisition unit that acquires a device message generated by the device via the local network based on a connectionless communication protocol; a transmission request unit that transmits, to the device, transmission request information that requests the device to transmit the device message; The second communication control device, a second message acquisition unit that acquires, via the local network, a device message generated by the device, and stores the acquired device message in a message buffer that can store all of the device messages transmitted from the device that is a destination of the transmission request information; Communication systems.

2. Further comprising a server; The second communication control device further includes an information transmission unit that transmits device information including the device message stored in the message buffer to the server. The communication system according to claim 1 .

3. A server; a first communication control device connected to a local network to which devices are connected; a second communication control device connected to the local network; The server, a transmission request unit configured to transmit, to the first communication control device, transmission request information requesting the device to transmit a device message; The first communication control device a message transmitting unit that transmits the transmission request information transmitted from the server to the device via the local network based on a connectionless communication protocol; a first message acquisition unit that acquires a device message generated by the device via the local network based on a connectionless communication protocol; The second communication control device, a second message acquisition unit that acquires, via the local network, a device message generated by the device, and stores the acquired device message in a message buffer that can store all of the device messages transmitted from the device that is the destination of the transmission request information; an information transmitting unit that transmits device information including the device message stored in the message buffer to the server; having Communication systems.

4. The server, a device information storage unit that stores the device information in association with device identification information that identifies the second communication control device; and an information acquisition unit that, when acquiring the device information transmitted from the second communication control device, stores the acquired device information in the device information storage unit in association with the device identification information of the second communication control device that is a transmission source of the device information. The communication system according to claim 3.

5. A first communication control device connected to a local network to which a device is connected; a second communication control device connected to the local network; The first communication control device a first message acquisition unit that acquires a device message generated by the device via the local network based on a connectionless communication protocol; a transmission request unit that transmits, to the device, transmission request information that requests the device to transmit the device message; a transmission request determination unit that determines whether the transmission request information is to be multicast or broadcast to the device; an acquisition request unit that transmits, when it is determined that the transmission request information is multicast or broadcast to the device, acquisition request information requesting the second communication control device to acquire the device message transmitted from the device, to the second communication control device; The second communication control device, a second message acquisition unit that acquires, via the local network, a device message generated by the device, and stores the acquired device message in a message buffer that can store all of the device messages transmitted from the device that is the destination of the transmission request information; an acquisition request determination unit that determines whether the acquisition request information has been acquired; When it is determined that the acquisition request information has been acquired, the second message acquisition unit acquires a device message generated by the device via the local network. Communication systems.

6. A first communication control device connected to a local network to which a device is connected; a second communication control device connected to the local network; The first communication control device a first message acquisition unit that acquires a device message generated by the device via the local network based on a connectionless communication protocol; a transmission request unit that transmits, to the device, transmission request information that requests the device to transmit the device message; The second communication control device, a second message acquisition unit that acquires a device message generated by the device via the local network and stores the acquired device message in a message buffer that can store all of the device messages transmitted from the device that is a destination of the transmission request information; Either the first communication control device or the second communication control device, a multicast adoptability determination unit that determines whether or not multicast transmission can be adopted as a method for transmitting the transmission request information based on a result of a comparison between device identification information for identifying the device that is a source of the device message, which can be obtained by transmitting the transmission request information to the device via multicast, and the device identification information of the device that is a source of the device message, which can be obtained by transmitting the transmission request information to the device via broadcast, Communication systems.

7. A first communication control device connected to a local network to which a device is connected; a second communication control device connected to the local network; The first communication control device a first message acquisition unit that acquires a device message generated by the device via the local network based on a connectionless communication protocol; a transmission request unit that transmits, to the device, transmission request information that requests the device to transmit the device message; The second communication control device, a second message acquisition unit that acquires a device message generated by the device via the local network and stores the acquired device message in a message buffer that can store all of the device messages transmitted from the device that is a destination of the transmission request information; the second communication control device connects to or disconnects from the local network depending on a communication state between the device and the first communication control device; Communication systems.

8. A communication control method using a first communication control device connected to a local network to which a device is connected and a second communication control device different from the first communication control device, The first communication control device acquires a device message generated by the device via the local network based on a connectionless communication protocol; a step of the first communication control device transmitting, to the device, transmission request information for requesting the device to transmit the device message; The second communication control device acquires, via the local network, a device message generated by the device, and stores the acquired device message in a message buffer capable of storing all of the device messages transmitted from the device that is the destination of the transmission request information. Communications control method.

9. Computer, a first message acquisition unit that acquires a device message generated by the device via a local network to which the device is connected based on a connectionless communication protocol; a transmission request unit that transmits, to the device, transmission request information that requests the device to transmit the device message to another communication control device; A program to function as a

10. Computer, a second message acquisition unit that acquires, in response to acquisition of transmission request information transmitted from another communication control device, requesting an equipment message to be transmitted to the equipment, an equipment message generated by the equipment, from the equipment via a local network to which the equipment is connected, and stores the acquired equipment message in a message buffer that can store all of the equipment messages transmitted from the equipment that is the destination of the transmission request information requesting the equipment message to be transmitted to the equipment; A program to function as a

Images