Communication terminal device, information communication system, program, and information communication method

Abstract

To provide a technique for preventing unintended weeding out of parent devices in a technique for detecting a situation in which a plurality of parent devices is actually operating and eliminating coexistence of the parent devices.SOLUTION: A communication terminal device 10 having a master device operation mode that operates as a master device and a slave device operation mode that operates as a slave device is provided with: a communication partner determination unit 233 that determines on the basis of master device information 202 received by its own device whether a source of the received master device information 202 is an in-group communication destination; a master device monitoring unit 231 that monitors whether the in-group communication destination is a master device, according to a determination result by the communication partner determination unit 233; and a switching unit 232 that switches the master device operation mode of the own device to the slave device operation mode when the master device monitoring unit 231 detects the presence of a master device other than the own device, while the own device is operating in the master device operation mode.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a technique for determining a master device and a slave device in an information communication system including a plurality of communication terminal devices.

Background Art

[0002] Conventionally, in a group of devices that should form one network, a technique for detecting a situation where a plurality of master devices coexist and determining one master device is described in, for example, Patent Document 1.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Recently, for example, the communication terminal device of electric equipment has advanced, and cases have occurred in which a plurality of networks composed of these electric equipment are installed by connecting these electric equipment to a network. That is, with the emergence of large-scale networks, there are cases where the networks themselves are grouped according to the installation location, the number of terminals, or the application.

[0005] When a plurality of networks are grouped, in the technique described in Patent Document 1, for example, if communication in a network of another group is intercepted unintentionally, it is misrecognized as a state where a plurality of master devices coexist, and a plurality of networks that should be independent networks are integrated by one master device, resulting in a problem.

[0006] The present invention has been made in view of the above problems, and in a technique for detecting a situation where a plurality of master devices are actually operating and eliminating the coexistence of master devices, an object is to provide a technique for preventing unintended obsolescence of master devices.

Means for Solving the Problems

[0007] In order to solve the above problems, the invention of claim 1 is a communication terminal device connected to a network and performing data communication with via the network, which has a master device operation mode operating as a master device and a slave device operation mode operating as a slave device, and stores in appropriate information serving as a reference for switching the operation mode between the master device operation mode and the slave device operation mode, determination reference information serving as a reference for determining the priority of the own device as a master device, storage means, based on the information received by the own device, communication partner determination means for determining whether the transmission source of the received information is, according to the determination result by the communication partner determination means, master device monitoring means for monitoring whether is a master device, acquisition means for acquiring the determination reference information in the detected as a master device by the master device monitoring means, when the own device is operating in the master device operation mode and the master device monitoring means detects the existence of a master device other than the own device, based on the determination reference information of the own device and the determination reference information in the detected as a master device by the master device monitoring means, switching means for switching the master device operation mode of the own device to the slave device operation mode. Destination within the group and, Destination within the group Destination within the group Destination within the group Destination within the group On the other hand, when the master unit monitoring means does not detect the presence of a master unit other than the own unit, it ignores it without switching the master unit operation mode of the own unit to the slave unit operation mode

[0008] Further, the invention of claim 2 is a communication terminal device according to the invention of claim 1, wherein the storage means stores terminal identification information for individually identifying the, and the communication partner determination means determines whether the transmission source of the received information is according to whether identification information for identifying the transmission source included in the received information is included in the terminal identification information stored in the storage means. Destination within the group Destination within the group

[0009] ​​​​​​​ Further, the invention according to claim 3 is a communication terminal device according to the invention of claim 1, wherein the storage means stores parent device candidate identification information for individually identifying parent device candidates among the Destination within the group , and the communication partner determination means determines whether or not the source of the received information is the Destination within the group by determining whether or not the identification information for identifying the source included in the received information is included in the parent device candidate identification information stored in the storage means.

[0010] Further, the invention according to claim 4 is a communication terminal device according to the invention of claim 1, wherein the storage means stores group Destination within the group for identifying the same from communication terminal devices of other groups, and the communication partner determination means collates the group identification information stored in the storage means with the identification information for identifying the source included in the received information, thereby determining whether or not the source of the received information is the Identification information . Destination within the group

[0011] Further, the invention according to claim 5 is a communication terminal device connected to a network and performing data communication with Destination within the group via the network, having a slave device operation mode in which it operates as a slave device, a communication partner determination means for determining whether or not the source of the received information is the Destination within the group based on the information received by the own device, and a master device monitoring means for monitoring whether or not a second master device other than the first master device exists in the Destination within the group when the own device is operating in the slave device operation mode and the first master device to which the own device is registered is operating in the master device operation mode as a master device, and acquisition means for acquiring first determination reference information serving as a reference for determining the priority of the first master device as a master device and second determination reference information serving as a reference for determining the priority of the second master device as a master device, and when it is determined by the master device monitoring means that the second master device exists, determining either the first master device or the second master device as the master device for the own device based on the first determination reference information and the second determination reference informationOn the other hand, when the master unit monitoring means does not detect the presence of the second master unit, the first master unit is maintained .

[0012] Also, the invention according to claim 6 is an information communication system including a plurality of communication terminal devices connected to a network, wherein each of the communication terminal devices has a master operation mode in which the device operates as a master unit and a slave operation mode in which the device operates as a slave unit, and stores, in appropriate information serving as a criterion for switching the operation mode between the master operation mode and the slave operation mode, determination criterion information serving as a criterion for determining the priority of the device as a master unit. The communication terminal device further includes communication partner determination means for determining whether or not the transmission source of the received information is one of the plurality of communication terminal devices based on the information received by the device, master unit monitoring means for monitoring whether or not the one determined by the communication partner determination means is a master unit, acquisition means for acquiring the determination criterion information in the one detected as a master unit by the master unit monitoring means, and switching means for switching the master operation mode of the device to the slave operation mode based on the determination criterion information of the device and the determination criterion information in the one detected as a master unit by the master unit monitoring means when the master unit monitoring means detects the presence of a master unit other than the device while the device is operating in the master operation mode. Destination within the group whether or not the one determined by the communication partner determination means is a master unit, acquisition means for acquiring the determination criterion information in the one detected as a master unit by the master unit monitoring means, and switching means for switching the master operation mode of the device to the slave operation mode based on the determination criterion information of the device and the determination criterion information in the one detected as a master unit by the master unit monitoring means when the master unit monitoring means detects the presence of a master unit other than the device while the device is operating in the master operation mode. Destination within the group whether or not the one determined by the communication partner determination means is a master unit, acquisition means for acquiring the determination criterion information in the one detected as a master unit by the master unit monitoring means, and switching means for switching the master operation mode of the device to the slave operation mode based on the determination criterion information of the device and the determination criterion information in the one detected as a master unit by the master unit monitoring means when the master unit monitoring means detects the presence of a master unit other than the device while the device is operating in the master operation mode. Destination within the group acquisition means for acquiring the determination criterion information in the one detected as a master unit by the master unit monitoring means, and switching means for switching the master operation mode of the device to the slave operation mode based on the determination criterion information of the device and the determination criterion information in the one detected as a master unit by the master unit monitoring means when the master unit monitoring means detects the presence of a master unit other than the device while the device is operating in the master operation mode. Destination within the group acquisition means for acquiring the determination criterion information in the one detected as a master unit by the master unit monitoring means, and switching means for switching the master operation mode of the device to the slave operation mode based on the determination criterion information of the device and the determination criterion information in the one detected as a master unit by the master unit monitoring means when the master unit monitoring means detects the presence of a master unit other than the device while the device is operating in the master operation mode. On the other hand, when the master unit monitoring means does not detect the presence of a master unit other than the own unit, it ignores it without switching the master unit operation mode of the own unit to the slave unit operation mode switching means for switching the master operation mode of the device to the slave operation mode based on the determination criterion information of the device and the determination criterion information in the one detected as a master unit by the master unit monitoring means when the master unit monitoring means detects the presence of a master unit other than the device while the device is operating in the master operation mode.

[0013] Also, the invention according to claim 7 is a computer-readable program executed by a computer connected to a network and performing data communication with via the network, wherein the execution of the program by the computer causes the computer to have a master operation mode in which the computer operates as a master unit and a slave operation mode in which the computer operates as a slave unit, and stores, in appropriate information serving as a criterion for switching the operation mode between the master operation mode and the slave operation mode, determination criterion information serving as a criterion for determining the priority of the computer as a master unit. The computer further includes communication partner determination means for determining whether or not the transmission source of the received information is the based on the information received by the computer, and, according to the determination result by the communication partner determination means, Destination within the group whether or not the transmission source of the received information is the based on the information received by the computer, and, according to the determination result by the communication partner determination means, Destination within the group whether or not the transmission source of the received information is the based on the information received by the computer, and, according to the determination result by the communication partner determination means, Destination within the groupa master device monitoring means for monitoring whether the device is a master device or not, and the Destination within the group acquisition means for acquiring the determination reference information in the above, and when the own device is operating in the master device operation mode, if the master device monitoring means detects the presence of a master device other than the own device, the determination reference information of the own device and the Destination within the group determination reference information of the above are used to switch the master device operation mode of the own device to the slave device operation mode. On the other hand, when the master unit monitoring means does not detect the presence of a master unit other than the own unit, it ignores it without switching the master unit operation mode of the own unit to the slave unit operation mode It functions as a communication terminal device including a switching means.

[0014] Also, the invention according to claim 8 is a computer-readable program connected to a network and performing data communication with the Destination within the group via the network. The execution of the program by the computer causes the computer to have a slave device operation mode in which it operates as a slave device, and based on the information received by the own device, determines whether the source of the received information is the Destination within the group or not. When the own device is operating in the slave device operation mode and the first master device registered by the own device is operating in the master device operation mode as a master device, according to the determination result by the communication partner determination means, monitors whether a second master device other than the first master device exists in the Destination within the group above, and includes acquisition means for acquiring first determination reference information that is a criterion for determining the priority of the first master device as a master device and second determination reference information that is a criterion for determining the priority of the second master device as a master device. When the master device monitoring means determines that the second master device exists, based on the first determination reference information and the second determination reference information, determines either the first master device or the second master device as the master device for the own device. On the other hand, when the master unit monitoring means does not detect the presence of the second master unit, the first master unit is maintained It functions as a communication terminal device.

[0015] Further, the invention according to claim 9 is an information communication method by a plurality of communication terminal devices having a master device operation mode operating as a master device and a slave device operation mode operating as a slave device. For each of the plurality of communication terminal devices, a step of storing, in appropriate information serving as a criterion for switching an operation mode between the master device operation mode and the slave device operation mode, determination criterion information serving as a criterion for determining the priority of the own device as a master device; a step of determining, by a communication partner determination means, whether or not the transmission source of the received information is an in-group communication destination among the plurality of communication terminal devices based on the information received by the communication terminal device; a step of monitoring, in the communication terminal device, whether or not the in-group communication destination is a master device according to a determination result by the communication partner determination means; a step of acquiring determination criterion information at the in-group communication destination detected as a master device; when the communication terminal device is operating in the master device operation mode and a master device is detected from the in-group communication destination, while switching the master device operation mode of the communication terminal device to the slave device operation mode based on the determination criterion information of the communication terminal device and the determination criterion information of the in-group communication destination detected as a master device , the and, when the presence of a master device that is an in-group communication destination is not detected, a step of ignoring without switching the master device operation mode of the communication terminal device to the slave device operation mode.

Advantages of the Invention

[0016] The invention according to claim 1 is a communication terminal device that performs data communication with other communication terminal devices via a network, comprising: a communication partner determination means for determining whether or not the transmission source of the received information is another communication terminal device based on the information received by the own device; a master device monitoring means for monitoring whether or not another communication terminal device is a master device according to the determination result by the communication partner determination means; and a switching means for switching the master device operation mode of the own device to a slave device operation mode based on the determination reference information of the own device and the determination reference information in another communication terminal device detected as a master device by the master device monitoring means when the master device monitoring means detects the existence of a master device other than the own device while the own device is operating in the master device operation mode. Thereby, it is possible to prevent the network from being integrated with other networks by misidentifying a communication terminal device other than another communication terminal device as a master device.

[0017] Further, the invention according to claim 5 is a communication terminal device that performs data communication with other communication terminal devices via a network, comprising: a communication partner determination means for determining whether or not the transmission source of the received information is another communication terminal device based on the information received by the own device; and a master device monitoring means for monitoring whether or not a second master device other than the first master device exists among other communication terminal devices according to the determination result by the communication partner determination means when the own device is operating in the slave device operation mode and the first master device in which the own device is registered is operating in the master device operation mode as a master device. When it is determined by the master device monitoring means that the second master device exists, either the first master device or the second master device is determined as the master device for the own device based on the first determination reference information and the second determination reference information. Thereby, it is possible to prevent the communication terminal device from being registered as the master device of another network by misidentifying a communication terminal device other than another communication terminal device as a master device.

[0018] The invention according to claim 6 is an information communication system including a plurality of communication terminal devices connected to a network. The communication terminal device includes a communication partner determination means for determining, based on the information received by the own device, whether the transmission source of the received information is another communication terminal device other than the own device among the plurality of communication terminal devices; a master device monitoring means for monitoring whether another communication terminal device is a master device according to the determination result by the communication partner determination means; and a switching means for switching the master device operation mode of the own device to a slave device operation mode based on the determination reference information of the own device and the determination reference information in another communication terminal device detected as the master device by the master device monitoring means when the master device monitoring means detects the existence of a master device other than the own device while the own device is operating in the master device operation mode. Thereby, it is possible to prevent the network from being integrated with another network by misidentifying a communication terminal device other than another communication terminal device as the master device.

[0019] The invention according to claim 7 is a computer-readable program for performing data communication with another communication terminal device via a network. The execution of the program by the computer causes the computer to function as a communication terminal device including a communication partner determination means for determining, based on the information received by the own device, whether the transmission source of the received information is another communication terminal device; a master device monitoring means for monitoring whether another communication terminal device is a master device according to the determination result by the communication partner determination means; and a switching means for switching the master device operation mode of the own device to a slave device operation mode based on the determination reference information of the own device and the determination reference information of another communication terminal device detected as the master device by the master device monitoring means when the master device monitoring means detects the existence of a master device other than the own device while the own device is operating in the master device operation mode. Thereby, it is possible to prevent the network from being integrated with another network by misidentifying a communication terminal device other than another communication terminal device as the master device.

[0020] Also, claim 8 described in The invention is a computer-readable program for performing data communication with other communication terminal devices via a network. When the program is executed by the computer, the computer is caused to function as a communication partner determination means for determining whether the transmission source of the received information is another communication terminal device based on the information received by the own device, and a parent device monitoring means for monitoring whether a second parent device other than the first parent device exists among other communication terminal devices when operating in the child device operation mode and when the first parent device registered by the own device is operating in the parent device operation mode as the parent device. When it is determined by the parent device monitoring means that the second parent device exists, the computer is caused to function as a communication terminal device for determining either the first parent device or the second parent device as the parent device for the own device based on the first determination reference information and the second determination reference information. Thereby, it is possible to prevent the computer from being registered as the parent device of another network by misidentifying a communication terminal device other than another communication terminal device as the parent device.

[0021] Also, claim 9 described in The invention is an information communication method by a plurality of communication terminal devices. For each of the plurality of communication terminal devices, a communication partner determination means for determining whether the transmission source of the received information is another communication terminal device among the plurality of communication terminal devices based on the information received by the communication terminal device, a step of monitoring whether another communication terminal device is a parent device according to the determination result by the communication partner determination means in the communication terminal device, and when the communication terminal device is operating in the parent device operation mode, a step of switching the parent device operation mode of the communication terminal device to the child device operation mode based on the determination reference information of the communication terminal device and the determination reference information of another communication terminal device detected as the parent device when the parent device is detected from another communication terminal device. Thereby, it is possible to prevent the network from being integrated with another network by misidentifying a communication terminal device other than another communication terminal device as the parent device.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, unless otherwise specified in the following description, the descriptions regarding directions and orientations correspond to the drawings for the convenience of the description, and do not limit, for example, the implementation products, products, or the scope of rights.

[0024] Also, the functions of the elements disclosed herein may be implemented using a general-purpose processor, a dedicated processor, an integrated circuit, an ASIC (Application Specific Integrated Circuit), a conventional circuit configuration, and / or a circuit configuration or processing circuit configuration that includes a combination thereof, which is configured to execute the disclosed elements or programmed to execute the disclosed functions. When a processor includes transistors and other circuit configurations therein, it is regarded as a processing circuit configuration or a circuit configuration. In the present disclosure, a circuit configuration, unit, or means is hardware that executes the recited functions or hardware programmed to realize the functions. The hardware may be any hardware disclosed herein or other known ones that are programmed to execute the recited functions or configured to execute the functions. When the hardware is a processor that may be regarded as a certain type of circuit configuration, the circuit configuration, means, or unit is a combination of hardware and software, software used to configure the hardware, and / or a processor.

[0025] <1. First Embodiment> FIG. 1 is a diagram showing an information communication system 1 in the first embodiment. The information communication system 1 includes a plurality of communication terminal devices 10, 11, 12, 13, 14, 15 connected to a network 91.

[0026] Note that, in FIG. 1, six communication terminal devices 10, 11, 12, 13, 14, 15 are illustrated. However, the number of communication terminal devices included in the information communication system 1 is not limited to six.

[0027] Also, FIG. 1 shows communication terminal devices 20, 21 connected to a network 92 different from the network 91. The communication terminal devices 20, 21 are not devices that constitute the information communication system 1. In the following description, it is assumed that in the network 92, the communication terminal device 20 operates as a master device and the communication terminal device 21 operates as a slave device.

[0028] In the first embodiment, the network 91 is a PLC (Power Line Communication) network. Therefore, the network 91 is a wired communication network using commercial power line cables. However, the network 91 is not limited to such a form. That is, the network 91 may be a wired communication network other than PLC, or may be a wireless communication network. Further, the network 91 may be constructed as a communication network in which a wired communication network and a wireless communication network coexist.

[0029] Between the network 91 and the network 92, "crosstalk" may occur as indicated by the two-dot chain line arrow in FIG. 1. Crosstalk is an unintended communication between the network 91 and the network 92, which are configured as separate groups, and the details will be described later.

[0030] As already described, the communication terminal devices 10, 11, 12, 13, 14, 15 shown in FIG. 1 are connected to the common network 91 and form one group. In the following description, a communication partner within the group of the information communication system 1 (within the network 91) (not including the own device because it is the partner) may be referred to as an "intra-group communication destination". For example, the intra-group communication destinations for the communication terminal device 10 are the other communication terminal devices 11, 12, 13, 14, 15, and do not include the communication terminal device 10 which is the own device and the communication terminal devices 20, 21. In this way, the intra-group communication destination is a normal communication partner for the communication terminal devices 10, 11, 12, 13, 14, 15.

[0031] On the one hand, in the following description, a communication partner outside the group of the information communication system 1 may be referred to as an "external-group communication destination". For example, the external-group communication destinations for the communication terminal device 10 are the communication terminal devices 20 and 21 connected to the network 92. As already described, communication between the communication terminal devices 10, 11, 12, 13, 14, and 15 and the communication terminal devices 20 and 21 may be established due to crosstalk (the communication terminal devices 20 and 21 may become communication partners). Thus, the external-group communication destinations are unintended communication partners for the communication terminal devices 10, 11, 12, 13, 14, and 15.

[0032] The communication terminal devices 10, 11, and 12 included in the communication terminal devices 10, 11, 12, 13, 14, and 15 have a master device operation mode in which they operate as a master device and a slave device operation mode in which they operate as a slave device. That is, the communication terminal devices 10, 11, and 12 are devices having both functions as a master device and a slave device. In the following description, the communication terminal devices 10, 11, and 12 are assumed to be devices having the same functions and configurations. However, the communication terminal devices 10, 11, and 12 are not limited to being completely identical devices.

[0033] On the other hand, the communication terminal devices 13, 14, and 15 are devices having a function as a slave device but not having a function as a master device. In the following description, the communication terminal devices 13, 14, and 15 are assumed to be devices having the same functions and configurations. However, the communication terminal devices 13, 14, and 15 are not limited to being completely identical devices.

[0034] In the following description, unless otherwise specified, the configuration and functions of the communication terminal devices 10, 11, 12, 13, 14, and 15 will be described taking the communication terminal device 10 as an example. However, as already described, since the communication terminal devices 13, 14, and 15 do not have the functions and configurations as a master device, among the descriptions regarding the communication terminal device 10, the descriptions regarding the master device do not apply to the communication terminal devices 13, 14, and 15.

[0035] Figure 2 is a block diagram of the communication terminal device 10 in the first embodiment. The communication terminal device 10 includes a CPU 100 and a storage device 101.

[0036] The CPU 100 reads and executes the program 200 stored in the storage device 101, and performs operations on various data and generation of control signals, etc. Thereby, the CPU 100 has a function of controlling each component included in the communication terminal device 10 and calculating and creating various data. That is, the communication terminal device 10 is configured as a general computer.

[0037] The storage device 101 provides a function of storing various data in the communication terminal device 10. In other words, the storage device 101 stores electronically fixed information in the communication terminal device 10.

[0038] Examples of the storage device 101 include a RAM and a buffer used as a temporary working area of the CPU 100, a read-only ROM, a non-volatile memory (e.g., NAND memory, etc.), a hard disk for storing relatively large-capacity data, a portable storage medium (CD-ROM, DVD-ROM, PC card, SD card, USB memory, etc.) attached to a dedicated reading device, etc. In FIG. 2, the storage device 101 is illustrated as if it were a single structure. However, usually, the storage device 101 is composed of a plurality of types of devices adopted as necessary among the various devices (or media) exemplified above. That is, the storage device 101 is a general term for a group of devices having a function of storing data.

[0039] In addition, the actual CPU 100 is an electronic circuit with an internally mounted RAM that can be accessed at high speed. However, for the sake of explanation, the storage device included in such a CPU 100 will also be described as being included in the storage device 101. That is, data temporarily stored by the CPU 100 itself will also be described as being stored in the storage device 101. As shown in FIG. 2, the storage device 101 is used to store the program 200, the setting information 201, and the master unit information 202. However, the information stored in the storage device 101 is not limited to these.

[0040] The setting information 201 is information indicating various setting statuses in the communication terminal device 10. The setting information 201 is stored in a non-volatile storage medium among the various storage media constituting the storage device 101. Therefore, the content of the setting information 201 is not lost even when the power of the communication terminal device 10 is turned off. The information included in the setting information 201 will be described later.

[0041] The master unit information 202 is information regarding the master unit (which may include the own device) existing on the network 91. In a PLC, the communication terminal device 10 that has received information can acquire various additional information included in the information. Examples of such additional information include information regarding the destination, source, transfer destination, transfer source, transmission time, number of hops, or communication quality. However, the additional information is not limited to the information exemplified here.

[0042] Although details will be described later, based on the acquired additional information, the communication terminal device 10 checks the presence and various states of each communication terminal device 10, 11, 12, 13, 14, 15 on the network 91, and for example, detects a master unit other than the own device. Then, the communication terminal device 10 appropriately uses the additional information as the master unit information 202. That is, the communication terminal device 10 can edit the additional information to generate the master unit information 202. Furthermore, based on the additional information, the communication terminal device 10 actively communicates with the detected master unit and collects necessary information (not additional information) regarding the master unit, and also uses this information as the master unit information 202.

[0043] Further, when the communication terminal device 10 is the master device, it includes information regarding itself in the master device information 202. Therefore, the master device information 202 may include information other than the information received by the communication terminal device 10.

[0044] Also, for example, since the slave - dedicated communication terminal device 13 cannot be the master device, in principle, information regarding the communication terminal device 13 is not included in the master device information 202. However, for example, when the communication terminal device 10 is the master device, information regarding the communication terminal device 13 as a slave device registered by the communication terminal device 10 which is the master device may be included in the master device information 202. Indirectly, information regarding the communication terminal device 13 which is the slave device may also be included in the master device information 202.

[0045] Furthermore, when crosstalk occurs, since the communication terminal device 10 may receive information from a communication destination outside the group, information regarding the communication terminal device 20 which is the master device on the network 92 may be included in the master device information 202.

[0046] As shown in FIG. 2, the communication terminal device 10 further includes an operation unit 102, a display unit 103, a timer unit 104, and a communication unit 105.

[0047] The operation unit 102 is hardware for an operator or the like to input instructions to the communication terminal device 10. Examples of the operation unit 102 include various keys, buttons, switches, touch panels, pointing devices, or jog dials.

[0048] The display unit 103 is hardware having a function of outputting various data by displaying them to an operator or the like. Examples of the display unit 103 include lamps, LEDs, CRTs, liquid crystal displays, or liquid crystal panels.

[0049] The timer unit 104 is an electronic circuit having a function of measuring time. When the time set by the CPU 100 elapses, the timer unit 104 transmits that fact to the CPU 100 by an interrupt signal. The timer unit 104 in the communication terminal device 10 is used, for example, to measure the search elapsed time described later. In the following description, the interrupt signal transmitted from the timer unit 104 to the CPU 100 when the search elapsed time elapses is referred to as a "time-up signal".

[0050] The communication unit 105 has a function of connecting the communication terminal device 10 to the network 91 in a state where data communication is possible. As described above, the network 91 in the first embodiment is a PLC network. Therefore, the communication unit 105 is an electronic circuit (PLC module) for realizing the PLC function.

[0051] FIG. 3 is a diagram showing the functional blocks included in the communication terminal device 10 in the first embodiment together with the data flow. The communication control unit 230, the master unit monitoring unit 231, the switching unit 232, and the communication partner determination unit 233 shown in FIG. 3 are functional blocks realized when the CPU 100 operates according to the program 200. Note that the master unit monitoring unit 231 in the first embodiment has the communication partner determination unit 233 as shown in FIG. 3. However, the configuration is not limited to the master unit monitoring unit 231 having the communication partner determination unit 233. The determination result by the communication partner determination unit 233 may be configured to be transmitted to the master unit monitoring unit 231 that does not have the communication partner determination unit 233.

[0052] As shown in FIG. 3, the setting information 201 includes determination reference information 203, a mode identifier 204, a monitoring permission flag 205, a switching permission flag 206, a standby time 207, a black list 208, and terminal identification information 211.

[0053] The determination criterion information 203 is information indicating the MAC address previously assigned to the own device. Since the MAC address is information uniquely assigned to the communication terminal devices 10, 11, 12, 13, 14, 15, it is identification information for individually determining the communication terminal devices 10, 11, 12, 13, 14, 15.

[0054] Details will be described later, but in the information communication system 1 according to the first embodiment, the priority order as the master device is determined based on the magnitude relationship of the MAC addresses of the plurality of communication terminal devices 10, 11, 12. Therefore, in the communication terminal devices 10, 11, 12 that can be the master device, the determination criterion information 203 is not only identification information for identifying the own device, but also information serving as a criterion for determining the priority order as the master device of the own device within the plurality of communication terminal devices 10, 11, 12.

[0055] Note that since the communication terminal devices 13, 14, 15 will not be the master device, the determination criterion information 203 as information serving as a criterion for determining the priority order as the master device of the own device is unnecessary. However, the determination criterion information 203 in the first embodiment is the MAC address assigned to the own device, and is also information stored in the communication terminal devices 13, 14, 15 (and further the communication terminal devices 20, 21).

[0056] The mode identifier 204 is information indicating whether to start in the slave device operation mode or the master device operation mode at the time of restart. Details will be described later, but when the operation mode of the communication terminal device 10 is switched between the "master device operation mode" and the "slave device operation mode", the communication terminal device 10 is always restarted promptly. Therefore, during the operation of the communication terminal device 10, the current operation mode and the operation mode indicated by the mode identifier 204 almost always match.

[0057] That is, in the communication terminal device 10, the current operation mode can be confirmed by referring to the mode identifier 204 included in the setting information 201. In the following description, it is assumed that when the mode identifier 204 is "1", it means that the communication terminal device 10 is started as a slave unit, and when it is "0", it means that the communication terminal device 10 is started as a master unit. Also, the initial value of the mode identifier 204 is set to "1 (slave unit operation mode)".

[0058] Note that since the communication terminal devices 13, 14, and 15 do not have the master unit operation mode, they will not be started in the master unit operation mode at the time of restart. That is, since the communication terminal devices 13, 14, and 15 do not need to identify the operation mode, they do not necessarily need to store the mode identifier 204. For the information communication system 1, for example, when the mode identifier 204 does not exist, it may execute the same operation as when the mode identifier 204 is "1". However, the communication terminal devices 13, 14, and 15 in the first embodiment have the mode identifier 204, and the mode identifier 204 will be described as being fixed to "1".

[0059] The monitoring permission flag 205 is information indicating whether to permit monitoring by the master unit monitoring unit 231 described later. In the following description, it is assumed that when the monitoring permission flag 205 is "1", it means invalid (not permitted), and when it is "0", it means valid (permitted). Also, the initial value of the monitoring permission flag 205 is set to "1 (not permitted)".

[0060] The switching permission flag 206 is information indicating whether to permit switching of the operation mode. In the following description, it is assumed that when the switching permission flag 206 is "1", it means invalid (not permitted), and when it is "0", it means valid (permitted). Also, the initial value of the switching permission flag 206 is set to "1 (not permitted)".

[0061] Note that the communication terminal devices 13, 14, and 15 do not have the master device operation mode and operate only in the slave device operation mode. That is, the operation modes of the communication terminal devices 13, 14, and 15 cannot be switched. Therefore, the communication terminal devices 13, 14, and 15 may not store the switching permission flag 206. However, the communication terminal devices 13, 14, and 15 in the first embodiment have the switching permission flag 206, and the switching permission flag Group 206 is is described as being fixed to "1".

[0062] In addition, in the information communication system 1 of the present embodiment, if the monitoring permission flag 205 is "0", the process is executed assuming that the switching from the master device operation mode to the slave device operation mode is permitted regardless of the value of the switching permission flag 206. However, the configuration may be such that the permission or non-permission of switching from the master device operation mode to the slave device operation mode is also determined by the switching permission flag 206 (or a separately independent flag).

[0063] The standby time 207 indicates the time to be waited until the master device is actually found when the communication terminal device 10 is in the slave device operation mode, and the master device for the own device has not been determined and the search for the master device has been started. The standby time 207 is set in the timer unit 104 by the CPU 100 (master device monitoring unit 231) and is used to determine the timing at which the timer unit 104 generates a time-up signal. Although details will be described later, when the communication terminal device 10 starts searching for the master device, it waits until the standby time 207 set in the setting information 201 elapses, and if the master device cannot be found even after the standby time 207 has elapsed, it gives up searching for the master device.

[0064] The blacklist 208 is information recording devices that the communication terminal device 10 does not recognize as the master device. For example, when determining the master device for its own device, the communication terminal device 10 refers to the blacklist 208 and rejects registering as the master device the devices recorded in the blacklist 208.

[0065] In the first embodiment, the terminal identification information 211 is information storing identification information for individually identifying a plurality of communication terminal devices 10, 11, 12, 13, 14, 15 in six partitions. That is, the terminal identification information 211 is list information of members (communication terminal devices 10, 11, 12, 13, 14, 15) included in the information communication system 1. However, the terminal identification information 211 may not include the identification information of the own device. That is, the terminal identification information 211 may be the identification information of the communication destination within the group (excluding the own device).

[0066] In the first embodiment, as the identification information, the MAC addresses uniquely assigned to the communication terminal devices 10, 11, 12, 13, 14, 15 are used. Therefore, the MAC addresses of the plurality of communication terminal devices 10, 11, 12, 13, 14, 15 are stored in the terminal identification information 211. Although details will be described later, the communication terminal devices 10, 11, 12, 13, 14, 15 can determine whether the communication partner (communication destination) is a member constituting the same network 91 as the own device by collating the MAC address indicating the communication partner with the terminal identification information 211.

[0067] Note that the MAC addresses of devices that may become members in the future may be stored in the terminal identification information 211 in advance. In that case, the number of MAC addresses included in the terminal identification information 211 will be more than six.

[0068] The communication control unit 230 shown in FIG. 3 controls the communication unit 105 to realize PLC (data communication) between the device connected to the network 91 and the communication terminal device 10.

[0069] The communication control unit 230 designates the information stored in the storage device 101 and the transmission destination, and causes the communication unit 105 to transmit the information.

[0070] In addition, the communication control unit 230 stores the information received by the communication unit 105 in the storage device 101. As such a function, for example, when the communication unit 105 receives information (e.g., Hello packet) transmitted from a master device other than its own device to notify its existence, the communication control unit 230 creates (updates) the master device information 202 in the storage device 101 based on the received information.

[0071] Note that in the communication unit 105, communication may be established with a communication destination outside the group due to crosstalk. When the received information includes information regarding the master device, the communication control unit 230 creates the master device information 202 based on the received information and the like even if the received information is due to crosstalk.

[0072] The communication control unit 230 appropriately refers to the mode identifier 204 of the setting information 201. When the mode identifier 204 is "1", it realizes the processing as a slave device in the PLC (hereinafter referred to as "slave device processing"). On the other hand, when the mode identifier 204 is "0", the communication control unit 230 realizes the processing as a master device in the PLC (hereinafter referred to as "master device processing"). Since conventional techniques can be applied to both the slave device processing and the master device processing, detailed descriptions are omitted.

[0073] Furthermore, the communication control unit 230 causes the communication unit 105 to transmit and receive packets necessary to change the master device to which its own device is registered at that time in response to a signal from the switching unit 232 (hereinafter referred to as "master device switching signal"). When its own device was a master device when the master device switching signal was transmitted, the communication control unit 230 causes the communication unit 105 to transmit and receive packets necessary for its own device to switch from the master device to a slave device.

[0074] The master device monitoring unit 231 has a function of monitoring whether a communication destination within the group (other communication terminal devices) is a master device. In order for the master device monitoring unit 231 to monitor the existence of the master device on the network 91, it involves an operation of searching for the existence of the master device on the network 91.

[0075] As a technology similar to the functions realized by the master device monitoring unit 231, for example, Japanese Patent Application Laid-Open No. 2011-135608 proposes a function of searching for existing master devices (devices that can become master devices) when a wireless LAN device (communication terminal device) is started up. The principle by which the master device monitoring unit 231 searches for the presence of a master device on the network 91 can be realized by adopting such a conventional technology.

[0076] However, such a conventional technology is a technology for searching for a master device in a situation where there is a high possibility that the communication terminal device cannot establish its own communication, or in a situation where communication has not actually been established. That is, such a technology is implemented in a so-called "emergency situation" and is not a process implemented when communication has already been established and stable data communication has been achieved.

[0077] In contrast, the monitoring of the master device by the master device monitoring unit 231 is continuously executed not only in an emergency but also during normal times. That is, the search for the master device by the master device monitoring unit 231 is also executed during normal times. Here, the "normal times" referred to here means when the own device is operating normally as a master device, or when the master device for the own device has already been confirmed, etc., when the communication terminal device 10 can already perform normal data communication.

[0078] The master device monitoring unit 231 determines, based on the information received by the own device by the communication partner determination unit 233, whether the transmission source of the received information is another communication terminal device (intra-group communication destination).

[0079] Specifically, first, it is determined whether the information received by the own device is included in the master device information 202. The information received by the own device is information transmitted by a communication terminal device other than the own device (intra-group transmission destination or extra-group transmission destination). The case where the master device information 202 is created based on such information indicates that a communication terminal device other than the own device exists as a master device.

[0080] Therefore, when the information received by the own device is included in the master device information 202, the communication partner determination unit 233 refers to the received information and acquires the identification information indicating the transmission source of the received information. Further, when the acquired identification information is included in the terminal identification information 211, the communication partner determination unit 233 determines that the transmission source of the received information is a communication destination within the group. When the information received from the communication destination within the group is included in the master device information 202, the master device monitoring unit 231 recognizes the master device indicated by the information received from the communication destination within the group as the master device, and the group Internal communication determines that the previous device (other communication terminal device) is the master device.

[0081] On the other hand, when the acquired identification information is not included in the terminal identification information 211, the communication partner determination unit 233 determines that the transmission source of the received information is a communication destination outside the group. The master device indicated by the information received from the communication destination outside the group is highly likely to be a communication destination outside the group. For example, the master device (communication terminal device 20) indicated by the information received from the communication terminal device 21 is also a communication destination outside the group. Therefore, even when the information received from the communication destination outside the group is included in the master device information 202, the master device monitoring unit 231 ignores it without determining the master device indicated by the information received from the communication destination outside the group as the master device. Note that the master device monitoring unit 231 registers the master device indicated by the information received from the communication destination outside the group in the blacklist 208. At this time, the master device monitoring unit 231 may delete the information received from the communication destination outside the group from the master device information 202.

[0082] In addition, the master device monitoring unit 231 detects whether there are multiple master devices by monitoring whether the communication destination within the group is the master device. When the master device monitoring unit 231 detects the existence of multiple master devices, it transmits a signal indicating that fact (hereinafter referred to as the "coexistence detection signal") to the switching unit 232. Here, "when the existence of multiple master devices is detected" means that when the communication terminal device 10 is in the master device operation mode, it is when the existence of a master device other than the own device is detected, and when the communication terminal device 10 is in the slave device operation mode, it is when the existence of a master device other than the master device to which the own device is registered is detected (or when it is determined that multiple communication destinations within the group are master devices). Note that the master device monitoring unit 231 in the present embodiment performs normal monitoring only when the monitoring permission flag 205 included in the setting information 201 is "0 (permitted)".

[0083] In addition, the master device monitoring unit 231 has a function of setting the standby time 207 in the timer unit 104 to measure the search elapsed time, and a function of resetting the set standby time 207.

[0084] The switching unit 232, the details of which will be sequentially described, has a function of switching the operation mode of the communication terminal device 10 between a master device operation mode in which it operates as a master device and a slave device operation mode in which it operates as a slave device. Also, the switching unit 232 provides a function of switching the master device to which the own device is registered to another master device when the communication terminal device 10 is operating in the slave device operation mode. That is, the switching unit 232 has an operation mode switching function and a master device switching function for the slave device.

[0085] When the own device is operating in the master device operation mode, if the master device monitoring unit 231 detects the presence of a master device other than the own device, the switching unit 232 switches the master device operation mode of the own device to the slave device operation mode based on the determination reference information 203 of the own device and the determination reference information 203 of the master device other than the own device. More specifically, when operating in the master device operation mode, when the coexistence detection signal is transmitted, the switching unit 232 acquires the determination reference information 203 (MAC address) of the detected master device from the master device information 202, compares it with the determination reference information 203 (MAC address) of the own device, and switches the own device to the slave device operation mode when the own device has a lower priority as the master device.

[0086] When switching the own device to the slave device operation mode, first, the switching unit 232 rewrites the mode identifier 204 set in the setting information 201 to "1". Then, the switching unit 232 immediately restarts the communication terminal device 10 (own device).

[0087] Also, when there is a time-up signal from the timer unit 104, the switching unit 232 rewrites the mode identifier 204 to "0" and immediately restarts the communication terminal device 10 (own device). In this way, when the search elapsed time exceeds the standby time 207, the switching unit 232 switches the operation mode of the communication terminal device 10 to the master device operation mode.

[0088] However, since the switching unit 232 in the slave device dedicated communication terminal devices 13, 14, 15 does not operate in the master device operation mode, it does not have such an operation mode switching function. That is, the function of switching the operation mode between the master device operation mode and the slave device operation mode is a function provided by the switching unit 232 in the communication terminal devices 10, 11, 12.

[0089] Furthermore, when the switching unit 232 is operating in the slave device operation mode and a coexistence detection signal is transmitted, the switching unit 232 acquires the determined reference information 203 (MAC address) of the detected master device and the determined reference information 203 (MAC address) of the master device registered in the own device from the master device information 202 respectively, and compares them. When the priority of the master device registered in the own device is lower as a master device, the switching unit 232 transmits a master device switching signal to the communication control unit 230. When generating the master device switching signal, the switching unit 232 registers the master device registered in the own device in the blacklist 208.

[0090] The above is the description of the configuration and functions of the information communication system 1. Next, the information communication method in the information communication system 1 will be described.

[0091] Figures 4 to 6 are flowcharts showing the information communication method by the information communication system 1. It is assumed that the process of creating the necessary setting information 201 in each of the communication terminal devices 10, 11, 12, 13, 14, 15 and storing it in the respective storage devices 101 has been completed before the processes shown in Figures 4 to 6 are started. Also, it is assumed that the initial values of the monitoring permission flag 205 and the switching permission flag 206 of the setting information 201 in each of the communication terminal devices 10, 11, 12, 13, 14, 15 have already been rewritten by the construction staff as required.

[0092] When starting the process shown in Figure 4, the CPUs 100 of the communication terminal devices 10, 11, 12, 13, 14, 15 first refer to the mode identifier 204 and determine whether to start in the slave device operation mode (step S1). The determination in step S1 can be realized by determining whether the value of the mode identifier 204 is "1". Since the mode identifiers 204 of the communication terminal devices 13, 14, 15 are fixed to "1", the CPUs 100 of the communication terminal devices 13, 14, 15 always determine "Yes" in step S1.

[0093] When the mode identifier 204 is "0" and the communication terminal device 10 does not start in the slave unit operation mode (No in step S1), the communication terminal device 10 starts in the master unit operation mode. The communication terminal device 10 that has started in the master unit operation mode then executes the process shown in FIG. 6, the details of which will be described later.

[0094] When the mode identifier 204 is "1" and the communication terminal device 10 starts in the slave unit operation mode (Yes in step S1), the communication terminal device 10 starts in the slave unit operation mode.

[0095] When the communication terminal device 10 starts in the slave unit operation mode, the communication terminal device 10 needs to find the master unit on the network 91. Therefore, when it is determined Yes in step S1, the master unit monitoring unit 231 sets the standby time 207 in the timer unit 104 and causes the timer unit 104 to start measuring the search elapsed time. As a result, when the set standby time 207 has elapsed, the timer unit 104 transmits a timeout signal to the switching unit 232 at that timing.

[0096] When it is determined Yes in step S1, the communication control unit 230 determines whether a master unit exists based on the information received by the communication unit 105 (step S2). Note that for the master unit search procedure at the time of startup in step S2, for example, a conventional technique can be used, so a detailed description is omitted. However, the master unit whose existence is confirmed in step S2 is not limited to the in-group communication destination, and may be an out-group communication destination.

[0097] When the existence of the master unit cannot be confirmed (No in step S2), the switching unit 232 determines whether the standby time 207 (search elapsed time) has elapsed based on the presence or absence of the transmission of the timeout signal from the timer unit 104 (step S7).

[0098] If the standby time 207 has not elapsed, the time-up signal will not be transmitted. Therefore, the switching unit 232 determines No in step S7. In that case, the CPU 100 returns to step S2 and repeats the process. That is, the communication terminal devices 10, 11, 12 started in the sub-device operation mode will not switch to the master-device operation mode until the set standby time 207 elapses by executing step S7.

[0099] As described above, in the communication terminal devices 10, 11, 12, 13, 14, 15 in the present embodiment, the standby time 207 is the sum of a fixed value (common value) and the MAC address of the own device, and is set to be a unique value. That is, the timing at which the search elapsed time in step S7 times out (the state where the time of waiting while searching for the master device exceeds the standby time 207) is different in each of the communication terminal devices 10, 11, 12, 13, 14, 15. Therefore, even if the information communication system 1 is powered on and the respective communication terminal devices 10, 11, 12, 13, 14, 15 are started almost simultaneously, it is expected that the timings at which the determination in step S7 becomes "Yes" will not match.

[0100] As a result, even if the communication terminal devices 10, 11, 12 having the function of the master device are started simultaneously in a state where the master device does not exist on the network 91 (for example, the initial state at the time of installation), the one with the smallest value of the standby time 207 will switch to the master-device operation mode first. And once any one of the communication terminal devices 10, 11, 12 switches to the master device, thereafter, the determination in step S7 will not become "Yes" in other devices (the determination in step S2 becomes "Yes"). Therefore, the information communication system 1 can suppress a plurality of communication terminal devices 10, 11, 12 from switching to the master device simultaneously as compared with the case where no countermeasure is taken as in the prior art.

[0101] Also, in the present embodiment, among the communication terminal devices 10, 11, and 12, the one with the smallest value of the standby time 207 (the one that first switches to the master device operation mode) is the one with the smallest MAC address value. And the one with the smallest MAC address value is the one with the highest priority as the master device in the information communication system 1 in the present embodiment. By setting it so that the one with the higher priority as the master device switches to the master device first, the frequency of master device replacement in subsequent processing can also be suppressed.

[0102] Note that the standby time 207 in the present embodiment has been described as the sum of a fixed value (common value) and the own device's MAC address. On the other hand, the own device's MAC address is stored in the setting information 201 as information included in the determination reference information 203. Therefore, a common fixed value may be stored as the standby time 207, and the master device monitoring unit 231 may be configured to set the sum of the fixed value standby time 207 and the own device's MAC address indicated in the determination reference information 203 to the timer unit 104.

[0103] If the standby time 207 has already elapsed (Yes in step S7), the switching unit 232 determines whether the process of monitoring a master device other than the own device is permitted (step S8). Step S8 can be realized by the switching unit 232 referring to the monitoring permission flag 205 and determining whether the monitoring permission flag 205 is "0".

[0104] When the monitoring permission flag 205 is "1" (No in step S8), the communication terminal devices 10, 11, and 12 (CPU 100) return to the process from step S2. In this case, even for the communication terminal devices 10, 11, and 12, the switching unit 232 does not switch the operation mode to the "master device operation mode".

[0105] Although details will be described later, the communication terminal devices 10, 11, and 12 having the function as a master device have a function of monitoring the presence of master devices other than the own device even when the own device is in the master device operation mode. And when a device with a higher priority as a master device than the own device is detected as a master device, in order to eliminate the presence of a plurality of master devices, the communication terminal devices 10, 11, and 12 switch to the slave device operation mode.

[0106] However, when the communication terminal devices 10, 11, and 12 for which the function of monitoring the presence of master devices other than the own device is not permitted are switched to the master device operation mode, the communication terminal devices 10, 11, and 12, of course, cannot monitor the presence of master devices other than the own device. And the communication terminal devices 10, 11, and 12 that cannot detect the presence of a plurality of master devices cannot shift to the slave device operation mode even if, for example, a plurality of master devices are present. Therefore, the communication terminal devices 10, 11, and 12 limit, in step S8, so as not to switch to the master device operation mode when the function of monitoring the presence of master devices other than the own device is not permitted.

[0107] Thereby, the information communication system 1 can prevent the master devices from increasing disorderly on the network 91. Note that instead of providing the determination in step S8, when switching to the master device operation mode, a step of always rewriting the monitoring permission flag 205 to "0" may be added. In this case, for example, even if a situation where the master devices increase temporarily occurs for some reason, as time passes, the communication terminal devices 10, 11, and 12 with a lower priority automatically switch to the slave device operation mode, and the state where a plurality of master devices are present is eliminated.

[0108] When the monitoring permission flag 205 is "0" (Yes in step S8), the switching unit 232 further determines whether the switching of the operation mode is permitted (step S9). Step S9 can be realized by the switching unit 232 referring to the switching permission flag 206 and determining whether the switching permission flag 206 is "0".

[0109] When the switching permission flag 206 is "1" (No in step S9), the communication terminal device 10 (CPU 100) returns to the process from step S2. In this case, even for the communication terminal devices 10, 11, and 12, the switching unit 232 does not switch the operation mode to the "master device operation mode".

[0110] As described above, in the information communication system 1, by using the switching permission flag 206, it is possible to preset whether the operation mode can be switched for each of the communication terminal devices 10, 11, 12, 13, 14, and 15. Then, by appropriately checking this setting (switching permission flag 206), the switching unit 232 can prevent the operation modes of the communication terminal devices 10, 11, 12, 13, 14, and 15 from switching disorderly.

[0111] As can be understood from the previous explanations, if the monitoring permission flag 205 and the switching permission flag 206 are installed with the initial values of "1" in all the communication terminal devices 10, 11, and 12, the communication terminal devices 10, 11, and 12 that switch to the master device operation mode will not appear. Therefore, when installing the information communication system 1, it is necessary for the construction staff to select at least one of the communication terminal devices 10, 11, and 12 in advance and change the values of the monitoring permission flag 205 and the switching permission flag 206 to "0".

[0112] Such an operation is possible, for example, when the construction staff operates the operation unit 102 of the communication terminal devices 10, 11, and 12. That is, the information communication system 1 requests the construction staff to perform the setting operation at the time of installation. At first glance, this seems to impose a burden on the construction staff.

[0113] Here, an explanation will be given regarding the point that the initial values of the monitoring permission flag 205 and the switching permission flag 206 are both set to "1 (not permitted)".

[0114] First, when the monitoring permission flag 205 is set to "0 (permitted)", even when the network is operating normally, the process of frequently monitoring the coexistence state of the master unit (this process is also executed in the slave units) will occur, increasing the overhead. Therefore, there is a situation where it is preferable that the number of devices in which the monitoring permission flag 205 is set to "0" is as small as possible.

[0115] Also, in the information communication system 1 designed to constitute one network, it is originally desired that there is one master unit during normal times. Nevertheless, if a plurality of communication terminal devices 10, 11, 12 are permitted to operate as the master unit (the switching permission flag 206 is set to "0"), there is a risk that the situation where the master units coexist will occur more easily as the number of permitted devices (master unit candidates) increases. Even if the narrowing down to one master unit is automatically executed, that period will be a situation where normal data communication cannot be performed, which is not preferable.

[0116] Also, in a situation where all the communication terminal devices 10, 11, 12 can become the master unit, even if it is finally limited to one, there is a problem that it is uncertain which will be the final master unit. In the information communication system 1, if an unintended device becomes the master unit, there is also a risk that the performance originally planned will not be achieved.

[0117] Also, the information communication system 1 in the present embodiment assumes a business system installed in an office building or the like. The installation of such an information communication system 1 involves relatively large-scale construction work. Therefore, the person who performs this installation work is not an ordinary user, but usually a construction worker with specialized knowledge. That is, it is assumed that a construction worker who is an expert will be present during the installation work of the information communication system 1. Therefore, even if a setting operation (an operation of rewriting the initial value of the flag) for at least one of the communication terminal devices 10, 11, 12 is imposed on the construction worker, it is not such a large burden compared to the case of imposing the same operation on an ordinary user.

[0118] Therefore, as described above, in the information communication system 1 according to the present embodiment, the initial values of the monitoring permission flag 205 and the switching permission flag 206 of the communication terminal devices 10, 11, and 12 are both set to "1 (not permitted)", and the installation worker is configured to perform the setting operation. However, as already described, the setting operation is completed before the processes shown in FIGS. 4 to 6 are started.

[0119] If the purpose of reducing the burden on the installation worker is emphasized, it is of course possible to set the initial values of the monitoring permission flag 205 and the switching permission flag 206 of the communication terminal devices 10, 11, and 12 in the information communication system 1 to "0". When configured in this way, even if the installation worker does not perform a specific setting operation, the information communication system 1 converges to a state where only one of the communication terminal devices 10, 11, and 12 is operating in the master operation mode after a sufficient period of time.

[0120] Alternatively, the information communication system 1 may be designed to include a device that always starts in the master operation mode as a communication terminal device. For example, a large number of lighting devices may be provided as the communication terminal devices 10, 11, 12, 13, 14, and 15, and a controller that operates only in the master operation mode may be provided as a communication terminal device. It can be said that the probability of such a controller malfunctioning at the first startup during new installation is low. Therefore, at the time of new installation, it can be expected that the controller will start up normally, and since only the controller becomes the master device, there will be no conflict of master devices, and operation can be started relatively early.

[0121] After that, when the network 91 stabilizes, if the controller automatically (or selectively) rewrites the values of the monitoring permission flag 205 and the switching permission flag 206 of the communication terminal devices 10, 11, and 12 to "0", when the controller fails, the communication terminal devices 10, 11, and 12 can be configured to switch to the master operation mode. Furthermore, if the priority of the controller as the master device is set to the highest priority, when the controller is restored, the communication terminal devices 10, 11, and 12 that are operating in the master operation mode on behalf can be configured to switch to the slave operation mode.

[0122] Also, the information communication system 1 in the present embodiment has been described assuming a business system. However, the present invention is not limited to a business system and is also applicable to a home system.

[0123] Returning to FIG. 4, when the switching permission flag 206 is "0" (Yes in step S9), the switching unit 232 rewrites the mode identifier 204 to "0" (step S10). Then, after rewriting the mode identifier 204, the switching unit 232 immediately restarts the communication terminal device 10 (step S11). The communication terminal device 10 restarted in step S11 returns to the process of step S1.

[0124] As already described, the value set in the mode identifier 204 is not lost even by restarting the communication terminal device 10. Therefore, if step S1 is executed immediately after steps S10 and S11 are executed, since the mode identifier 204 is set to "0", it is determined as No in step S1. The processing after being determined as No in step S1 will be described later.

[0125] In the process shown in FIG. 4, it was described that when it is determined as No in steps S8 and S9, the process returns to the process of step S2 to search for the master device again. However, when steps S8 and S9 are executed, the waiting time 207 has already elapsed (Yes in step S7). Therefore, when it is determined as No in step S8 or step S9, the CPU 100 may execute error processing (for example, timeout display) to stop the operation. In particular, in the communication terminal devices 13, 14, and 15 that do not switch to the master device, it is never determined as Yes in step S9. Therefore, if it returns to step S2 every time it is determined as No in step S9, there is a risk of an infinite loop.

[0126] Next, the case where it is determined as Yes in step S2 of FIG. 4 will be described. The case where it is determined as Yes in step S2 is when the communication terminal device 10 is in the slave operation mode and there is a master device that can communicate with the own device.

[0127] When it is determined as Yes in step S2, the communication control unit 230 creates master device information 202 regarding the master device whose existence has been confirmed based on the information received by the communication unit 105 (step S3). When the received information includes information regarding the master device, the communication control unit 230 executes the process of step S3 by including the information regarding the master device in the master device information 202. The received information stores identification information for identifying the transmission source. Therefore, the master device information 202 created in step S3 can include the identification information of the transmission source.

[0128] Note that the master device information 202 created in step S3 does not have to be complete as the master device information 202. That is, based on some of the information that could be collected before step S3 is executed, transient master device information 202 may be created once. Also, as already described, the master device whose existence is confirmed at this time is not limited to the communication destination within the group and may be a communication destination outside the group.

[0129] When step S3 is executed, next, the master unit monitoring unit 231 determines whether the information received by the own unit is included in the master unit information 202. However, when step S3 is executed, since the own unit is a slave unit, the master unit information 202 does not include the information of the own unit (not the received information). That is, the master unit information 202 at this time always includes the received information. When the received information is included in the master unit information 202, the identification information (MAC address) of the master unit whose existence has been confirmed based on the received information is acquired. Next, the master unit monitoring unit 231 determines whether the acquired identification information of the master unit is registered in the blacklist 208 (step S4).

[0130] When the MAC address of the master unit whose existence has been confirmed is stored in the blacklist 208 (Yes in step S4), the master unit monitoring unit 231 determines that the master unit whose existence has been confirmed is not appropriate as the master unit of the own unit. In this case, the CPU 100 executes the processing from step S7 as already described, as in the case where the existence of the master unit is not confirmed.

[0131] When the MAC address of the master unit whose existence has been confirmed is not stored in the blacklist 208 (No in step S4), the communication partner determination unit 233 determines whether the master unit whose existence has been confirmed is a member constituting the information communication system 1 (step S5). The communication partner determination unit 233 in the first embodiment executes the processing of step S5 by determining whether the MAC address of the master unit acquired from the master unit whose existence has been confirmed is stored in the terminal identification information 211.

[0132] When the MAC address of the master unit whose existence has been confirmed is not stored in the terminal identification information 211 (No in step S5), the master unit monitoring unit 231 determines that the master unit whose existence has been confirmed is not appropriate as the master unit of the own unit.

[0133] When the MAC address of the master device confirmed to exist in step S2 of the first embodiment is not stored in the terminal identification information 211, it means that the master device is not a device connected to the network 91 (a device belonging to the same group as the own device), but is a communication destination outside the group.

[0134] As already described, in the information communication system 1, crosstalk may occur. Crosstalk is communication between the own device and a communication destination outside the group. Therefore, when a communication destination due to crosstalk is confirmed as the master device, the master device is a communication destination outside the group and is not any of the communication terminal devices 10, 11, 12, 13, 14, 15 constituting the information communication system 1. For example, when the communication terminal device 10 is activated as a slave device (when step S2 is executed) and recognizes a communication destination outside the group as the master device, the communication terminal device 10 is registered as a slave device with respect to the master device. In this case, the communication terminal device 10 becomes a communication destination outside the group.

[0135] Therefore, when the communication partner determination unit 233 determines No in step S5, the master device monitoring unit 231 adds the MAC address of the master device confirmed to exist at this time to the blacklist 208 (step S6), and executes the processing from step S7 already described in the same manner as when the existence of the master device is not confirmed. Thereby, the information communication system 1 can prevent the communication terminal devices 10, 11, 12, 13, 14, 15 from becoming communication destinations outside the group even if crosstalk occurs at startup.

[0136] On the other hand, when the MAC address of the master device whose existence has been confirmed is stored in the terminal identification information 211 (Yes in step S5), the master device monitoring unit 231 determines that the master device is a communication destination within the group. When it is determined Yes in step S5, the communication control unit 230 controls the communication unit 105 to transmit a packet requesting to register the own device as a slave device to the detected master device. As a result, a registration request is made from the communication terminal device 10 to the master device (Fig. 5: step S21).

[0137] The master device whose existence was confirmed in step S2 is the master device detected by the so-called "the early bird catches the worm" principle. That is, at this point, even if multiple master devices already exist on the network 91, the master device for which a registration request is made in step S21 is the master device detected earliest among the communication terminal devices 10, 11, and 12. However, when multiple master devices have already been detected in the communication terminal devices 10, 11, and 12, the superiority or inferiority may be determined based on the number of hops, communication quality, etc.

[0138] When step S21 is executed and the communication terminal device 10 is successfully registered as a master device, the communication terminal device 10 starts processing as a slave device (slave device processing) (step S22). In other words, by executing step S22, the communication terminal device 10 functions as a slave device in the PLC on the network 91.

[0139] Note that in a state where the communication terminal device 10 is registered with a new master device, it does not request registration with another master device. That is, after the communication terminal device 10 is registered with a normal master device, the risk of being registered again with the master device (inappropriate master device) registered in the blacklist 208 decreases. Therefore, the communication terminal device 10 may delete the master device registered in the blacklist 208 when its own device is registered with a new master device. However, the timing of deletion from the blacklist 208 is not limited to this. The communication terminal device 10 may delete the master device from the blacklist 208 when a predetermined time has elapsed since the master device was registered in the blacklist 208. Alternatively, when no master device is detected, the blacklist 208 may be cleared.

[0140] Next, the communication terminal device 10 creates (updates) the master device information 202 based on the information received in step S22 (step S23).

[0141] Note that in step S23, the communication terminal device 10 may separately request and collect information that cannot be obtained by the conventional handset processing (step S22). That is, the master device information 202 is not limited to the information obtained by executing the conventional handset processing. For example, it is conceivable that the determination criterion information 203 of the master device on the network 91 cannot be obtained only by the conventional handset processing. In such a case, in step S23, the communication terminal device 10 may request to transmit the determination criterion information 203 to the master device, and create the master device information 202 based on the information obtained as a response to this request (the information obtained in step S23).

[0142] Also, in the handset processing which is a conventional technique, there may be a case where information regarding the master device is collected and a process of creating a database regarding the master device is performed. Thus, the information created in the conventional technique may also be used as the master device information 202. That is, when the master device information 202 is completed in step S22, step S23 does not necessarily have to be executed separately and independently.

[0143] Also, although details will be described later, the communication terminal device 10 repeatedly executes steps S22 and S23. However, at the timing when the communication terminal device 10 executes step S23, there is not always new information that should be the master device information 202. Therefore, for example, when it is determined that the necessary information has not been obtained, the communication terminal device 10 may not create the master device information 202 in step S23.

[0144] When step S23 is executed, the communication terminal device 10 determines whether to disconnect from the network 91 (step S24).

[0145] When it is to disconnect (Yes in step S24), the communication terminal device 10 notifies its parent device of the intention to disconnect (sends a disconnection packet to the parent device). As a result, the communication terminal device 10 is deleted from the child device list of the parent device in which it was registered as a child device. The disconnected communication terminal device 10 returns to step S1 and starts searching for a new parent device. Note that when disconnecting, the communication terminal device 10 may register the parent device in which it was registered before disconnecting in the blacklist 208.

[0146] When the communication terminal device 10 does not disconnect (No in step S24), the parent device monitoring unit 231 determines whether the process of monitoring a parent device other than its own is permitted (step S25). Step S25 can be realized by the parent device monitoring unit 231 referring to the monitoring permission flag 205 and determining whether the monitoring permission flag 205 is "0".

[0147] When the monitoring permission flag 205 is "1" (No in step S25), the communication terminal device 10 (CPU 100) returns to step S22 and continues the child device process. In this case, the communication terminal device 10 does not check whether there is another parent device other than the parent device in which it is registered. In this way, by providing the monitoring permission flag 205 in the communication terminal device 10, the information communication system 1 can suppress the occurrence of overhead caused by monitoring other parent devices during normal times.

[0148] When the monitoring permission flag 205 is "0" (Yes in step S25), the parent device monitoring unit 231 refers to the parent device information 202 and checks whether there is another parent device other than the parent device in which it is registered (step S26). Step S26 can be executed by referring to the parent device information 202.

[0149] In this way, when the communication terminal device 10 is operating in the slave device operation mode, it can check whether there is another master device other than the master device to which the own device is registered. That is, the communication terminal device 10 can detect the existence of a plurality of master devices. Note that step S26 may include a process in which the communication terminal device 10 newly transmits a packet to search for other master devices. That is, the determination in step S26 does not have to rely only on the master device information 202 created in step S23.

[0150] When there is no other master device (No in step S26), the communication terminal device 10 (CPU 100) determines that the coexistence state of the master devices has not occurred, returns to step S22, and continues the slave device process. In this case, the communication terminal device 10 does not change the master device to which the own device is registered. In this way, when there is no other master device other than the master device to which the own device is registered (when the coexistence state of the master devices has not occurred), the communication terminal device 10 continues the normal slave device process.

[0151] When there is another master device (Yes in step S26), the communication partner determination unit 233 determines whether the master device is an in-group communication destination (another communication terminal device) according to the identification information of the other master device whose existence is confirmed in step S26 and the terminal identification information 211 (step S27).

[0152] When the communication partner determination unit 233 determines No in step S27, based on the determination result, the master device monitoring unit 231 determines that there is no master device other than the master device to which the own device is registered among the in-group communication destinations. In other words, it is determined that the master device whose existence is confirmed in step S26 is an out-of-group communication destination (for example, the communication terminal device 20).

[0153] At this time, the master device monitoring unit 231 determines that the coexistence state of the master device does not occur on the network 91, returns to step S22, and continues the slave device process. Also in this case, the communication terminal device 10 does not change the master device to which it is registered. Thus, even when another master device other than the master device to which the communication terminal device 10 is registered is detected, if the detected master device does not exist on the network 91, it can be determined that the coexistence state of the master device on the network 91 does not occur, and the normal slave device process is continued. Therefore, even when the communication terminal device 20 is detected due to crosstalk, the communication terminal device 10 is not registered to the communication terminal device 20.

[0154] When the communication partner determination unit 233 determines Yes in step S27, based on the determination result, the master device monitoring unit 231 determines that a master device other than the master device to which the own device is registered exists among the in-group communication destinations, and transmits a coexistence detection signal to the switching unit 232.

[0155] When the coexistence detection signal is transmitted while operating in the slave device operation mode, the switching unit 232 acquires and compares the determination reference information 203 of all the coexisting master devices from the master device information 202, respectively. Then, it is determined whether there is a master device with a higher priority than the master device to which the own device is registered (step S28). As already described, in the present embodiment, the determination reference information 203 is the MAC address, and the master device with the higher priority is the one with the smaller MAC address in ascending order.

[0156] If the result in step S28 is No, the communication terminal device 10 (CPU 100) returns to step S22 and continues the slave device process. In this case, the communication terminal device 10 does not change the master device to which it is registered. Thus, when there is no other master device with a higher priority than the master device to which the communication terminal device 10 is registered on the network 91, the normal slave device process is continued.

[0157] If the answer in step S28 is Yes, the switching unit 232 generates a master device switching signal and transmits it to the communication control unit 230, and registers the master devices other than the master device with the highest priority in the blacklist 208 (step S29). Note that the communication control unit 230 to which the master device switching signal has been transmitted controls the communication unit 105 to transmit and receive packets for releasing the relationship with the registered master device. As a result, the relationship between the communication terminal device 10 and the master device with a lower priority is eliminated.

[0158] When step S29 is executed, the communication terminal device 10 returns to step S21. In step S21 executed at this time, the communication terminal device 10 (communication control unit 230) requests the master device with the highest priority to register the own device as a slave device.

[0159] Note that the master device with the highest priority may be transmitted from the switching unit 232 to the communication control unit 230 together with the master device switching signal. Alternatively, since all the master devices with a lower priority are registered in the blacklist 208, the communication control unit 230 may simply broadcast a registration request packet.

[0160] In this way, when the information communication system 1 detects a situation where a plurality of master devices exist in the network 91, it can register a slave device with a master device having a high priority as a master device without waiting for release from the master device. As a result, the time until communication between the new master device and the slave device is established can be shortened, and the time required for the return of the slave device that changes the master device can be shortened.

[0161] The above is mainly the processing when the communication terminal device 10 operates in the slave device operation mode. Next, the processing when the communication terminal device 10 operates in the master device operation mode will be described. The case where the communication terminal device 10 operates in the master device operation mode is the case where it is determined as No in step S1 shown in FIG. 4. And the case where it is determined as No in step S1 is the case where the mode identifier 204 is "0" when the communication terminal device 10 is activated.

[0162] When it is determined as No in step S1, the communication terminal device 10 executes the master device process (Fig. 6: step S31).

[0163] When the master device process ends, the communication control unit 230 creates (updates) the master device information 202 (step S32). Step S32 is the same as step S23.

[0164] Next, the master device monitoring unit 231 determines whether the process of monitoring a master device other than its own device is permitted (step S33). Similar to step S25, step S33 can be realized by the master device monitoring unit 231 referring to the monitoring permission flag 205 and determining whether the monitoring permission flag 205 is "0".

[0165] When the monitoring permission flag 205 is "1" (No in step S33), the communication terminal device 10 (CPU 100) returns to step S31 and continues the master device process. In this case, the communication terminal device 10 does not need to confirm whether there is another master device outside itself. In this way, by providing the monitoring permission flag 205 in the communication terminal device 10, the information communication system 1 can suppress the occurrence of overhead caused by monitoring other master devices during normal times even in the master device operation mode. For machines other than When the monitoring permission flag 205 is "0" (Yes in step S33), the master device monitoring unit 231 refers to the master device information 202 and checks whether there is another master device other than its own device (step S34). Step S34 can be executed by referring to the master device information 202.

[0166]

[0167] ​In this way, when the communication terminal device 10 is operating in the master device operation mode, it can confirm whether there is another master device other than itself. That is, the communication terminal device 10 can detect the existence of a plurality of master devices. Note that step S34 may include a process in which the communication terminal device 10 newly transmits a packet and searches for other master devices, similar to step S26. That is, the determination in step S34 does not necessarily rely only on the master device information 202 created in step S32.

[0168] When there is no other master device (No in step S34), the communication terminal device 10 (CPU 100) returns to step S31 and continues the master device process. In this case, the communication terminal device 10 does not switch the master device operation mode. In this way, when there is no other master device other than itself (when the coexistence state of master devices does not occur), the communication terminal device 10 continues the normal master device process.

[0169] When there is another master device (Yes in step S34), the communication partner determination unit 233 determines whether the master device is an in-group communication destination (another communication terminal device) according to the identification information of the other master device whose existence is confirmed in step S34 and the terminal identification information 211 (step S35).

[0170] When the communication partner determination unit 233 determines No in step S35, based on the determination result, the master device monitoring unit 231 determines that the other master device does not exist among the in-group communication destinations. In other words, it is determined that the master device whose existence is confirmed in step S34 is an out-of-group communication destination (for example, the communication terminal device 20).

[0171] At this time, the master device monitoring unit 231 determines that the coexistence state of the master device does not occur on the network 91, returns to step S31, and continues the master device process. In this case, the communication terminal device 10 does not switch the master device operation mode. Thus, when the communication terminal device 10 is operating in the master device operation mode, even if another master device other than itself is detected, if the detected master device does not exist on the network 91, it can be determined that the coexistence state of the master device on the network 91 does not occur, and the master device process is continued. Therefore, even if the communication terminal device 20 is detected due to crosstalk, the communication terminal device 10 does not transition to the slave device operation mode.

[0172] Crosstalk occurs when communication signals within another network 92 are mixed into the network 91. For example, when the cable in the network 91 picks up signals (such as signals of the communication terminal device 20) on another network 92 like an antenna. Also, for example, crosstalk occurs when the communication terminal device 10 receives radio waves transmitted by the communication terminal device 20 when wireless is used in the network 91.

[0173] Figures 7 to 10 are diagrams illustrating how the operation modes of the communication terminal devices 20, 21, 30, and 31 are switched. In Figures 7 to 10, the communication terminal devices 30 and 31 have a function of detecting the coexistence state of the master device and appropriately switching the operation mode of their own devices between the master device operation mode and the slave device operation mode. As a technology for realizing the communication terminal devices 30 and 31, for example, the technology described in Japanese Patent Application Laid-Open No. 2018-191116 can be used.

[0174] Note that the four boxes in Figures 7 to 10 respectively represent the communication terminal devices 20, 21, 30, and 31.

[0175] Also, the numbers within the boxes in FIGS. 7 to 10 indicate the symbols of the individual communication terminal devices 20, 21, 30, 31. That is, the "30" in "M30" indicates that the box is the communication terminal device 30.

[0176] Also, the alphabets in FIGS. 7 to 10 indicate the operation modes of the individual communication terminal devices 20, 21, 30, 31. That is, "M" indicates that it is operating in the "parent device operation mode", and "T" indicates that it is operating in the "child device operation mode".

[0177] Also, in FIGS. 7 to 10, the communication terminal devices 30, 31 marked with an asterisk indicate that the switching of the operation mode is permitted. On the other hand, the communication terminal devices 20, 21 without an asterisk indicate that the switching of the operation mode is not permitted. In the examples shown in FIGS. 7 to 10, it is assumed that the monitoring of the parent device is permitted in the communication terminal devices 30, 31.

[0178] Also, in FIGS. 7 to 10, the boxes without hatching indicate a state where the registration as a parent device or a child device has not been completed (unregistered state). On the other hand, the hatched boxes indicate a state where the registration as a parent device or a child device has been completed (however, it is not necessarily the final registration state). Also, the boxes with the same hatching indicate that they belong to the same group of parent devices.

[0179] Furthermore, in the examples shown in FIGS. 7 to 10, the MAC addresses of the communication terminal devices 20, 21, 30, 31 are assumed to be the symbols of the individual devices. That is, the MAC address of the communication terminal device 30 is described as "30".

[0180] FIG. 7 shows that the communication terminal device 30 is registered as the master device, and another communication terminal device 31 is registered as the slave device of the communication terminal device 30. That is, FIG. 7 shows a state in which only the communication terminal device 30 exists as one master device in the network 93, and the normal PLC network is already completed. Further, FIG. 7 shows that the communication terminal device 20 is registered as the master device on the network 92, and the communication terminal device 21 is registered as the slave device of the communication terminal device 20. Furthermore, it is assumed that no crosstalk occurs between the network 92 and the network 93 in the state shown in FIG. 7.

[0181] FIG. 8 shows a state immediately after crosstalk occurs between the network 92 and the network 93 from the state shown in FIG. 7. In the following description, it is assumed that communication is possible between the communication terminal device 20 and the communication terminal device 30. However, since crosstalk is an unintended communication, it is originally impossible to predict which devices it will occur between.

[0182] When the communication terminal device 30 operates in the master device operation mode and recognizes the communication terminal device 20 operating in the master device operation mode, the communication terminal device 30 recognizes the communication terminal device 20 as a master device other than itself and determines that a coexistence state of master devices has occurred. That is, when communication is established between the communication terminal device 20 and the communication terminal device 30 due to crosstalk, the communication terminal device 30 detects the coexistence state of master devices.

[0183] The communication terminal device 30 that has detected the coexistence state of master devices selects one master device to be retained in order to reduce the plurality of coexisting master devices to one. Here, the communication terminal device 30 compares its own MAC address "30" with the MAC address "20" of the communication terminal device 20 and determines that the communication terminal device 20, which is a master device other than itself, has a higher priority as a master device. That is, it is determined that the master device to be retained is the communication terminal device 20. Therefore, the communication terminal device 30 releases the slave device (communication terminal device 31) registered in itself and changes its operation mode to the slave device operation mode.

[0184] FIG. 9 shows a state in which the communication terminal device 30 has transitioned to a slave unit. As shown in FIG. 9, the alphabet of the box representing the communication terminal device 30 has changed to "T", and the communication terminal device 30 has shifted to the slave unit operation mode. Also, since the registration of the communication terminal devices 30 and 31 has been canceled, they are shown in an unregistered state (a state without hatching). The unregistered communication terminal devices 30 and 31 enter a state where they start searching for the master unit and wait until a new master unit is detected.

[0185] Crosstalk occurs between the communication terminal device 20 and the communication terminal device 30. Therefore, the communication terminal device 30 will request registration with the communication terminal device 20 (the remaining master unit). On the other hand, since the communication terminal device 31 cannot communicate with the communication terminal device 20, it cannot detect the communication terminal device 20 as the master unit. Therefore, the communication terminal device 31 changes its own operation mode to the master unit operation mode and transitions to the master unit.

[0186] FIG. 10 is a diagram showing a state in which the registration of the communication terminal devices 30 and 31 is completed. As shown in FIG. 10, the communication terminal device 30 is registered as a slave unit of the communication terminal device 20 and is incorporated into the network 92. However, in FIG. 10, the portion logically connected by crosstalk in the network 92 is shown by a solid line, but it is not physically connected by a power line, and the communication is unstable.

[0187] On the other hand, the communication terminal device 31 becomes the master unit and remains in the network 93, but is separated from the communication terminal device 30. Even in the state of FIG. 10, the communication terminal device 30 and the communication terminal device 31 are physically connected by a power line and communication is established, but this communication is regarded as crosstalk between the network 92 and the network 93.

[0188] As is clear from a comparison of FIG. 7 and FIG. 10, in the communication terminal devices 30 and 31, when crosstalk occurs, the network 93, which was originally designed to form a different group, cannot be maintained as designed.

[0189] Incidentally, if the communication terminal device 31 can communicate with the communication terminal device 20 via the communication terminal device 30 by hopping or the like, the communication terminal device 31 will also request registration from the communication terminal device 20. In this case, the communication terminal devices 20, 21, 30, and 31 will be integrated into one network 92. In any case, the state of the network 93 shown in FIG. 7 cannot be maintained.

[0190] Conventionally, it has not been widely assumed to group a plurality of communication terminal devices 20, 21, 30, and 31 connected to a PLC into a plurality of networks 92 and 93. That is, in an information communication system that employs a PLC, when crosstalk occurs, the specific problem that the network 93 is integrated with the network 92 that should be divided into different groups has not been assumed conventionally. However, due to the diversification of communication terminal devices and the explosive increase in the number of communication terminal devices, etc., a need has arisen to group the communication terminal devices connected to the PLC into a plurality of networks, and thus the above problem has emerged as a new issue.

[0191] In particular, in a PLC, the cable used to transmit signals is a power line. Compared with a dedicated communication cable, a power line has a relatively simple structure in terms of countermeasures against noise and is prone to crosstalk. Also, in a facility, power lines are usually laid in a bundled state of multiple lines. In such a laying state, the power lines constituting different groups of networks are in a state of being relatively close to each other and arranged in parallel for a relatively long distance. Due to such a laying state peculiar to power lines, a PLC is also prone to crosstalk.

[0192] However, as already described, in the information communication system 1 according to the first embodiment, even if a communication terminal device 20 that is an external communication destination of the group is detected as the master unit due to crosstalk, the communication terminal device 10 operating in the master unit operation mode does not transition to the slave unit operation mode. Therefore, by preventing the communication terminal device 10 from recognizing a communication terminal device 20 other than the internal communication destination of the group as the master unit, it is possible to prevent the network 91 from being integrated with another network 92.

[0193] Returning to FIG. 6, when the communication partner determination unit 233 determines Yes in step S35, based on the determination result, the master unit monitoring unit 231 determines that a master unit other than the own unit exists among the internal communication destinations of the group, and transmits a coexistence detection signal to the switching unit 232. When the coexistence detection signal is transmitted while operating in the master unit operation mode, the switching unit 232 acquires the determination reference information 203 of all master units other than the own unit from the master unit information 202, respectively, and compares it with the determination reference information 203 of the own unit stored in the setting information 201. Then, it is determined whether there is a master unit with a higher priority than the own unit (step S36).

[0194] If the result in step S36 is No, the communication terminal device 10 (CPU 100) returns to step S31 and continues the master unit process. In this case, the communication terminal device 10 does not switch to the slave unit operation mode. Thus, even if a coexistence state of the master unit occurs, for example, the communication terminal device 10 continues the normal master unit process when there is no other master unit with a higher priority than the own unit.

[0195] Thereby, in the information communication system 1, switching of the highest-priority master unit to the slave unit operation mode is prohibited. Therefore, for example, even if switching to the slave unit operation mode is permitted in all communication terminal devices 10, 11, and 12, at least one master unit will survive unless an unexpected situation such as a failure occurs.

[0196] If the answer is Yes in step S36, the switching unit 232 generates a master unit switching signal and transmits it to the communication control unit 230. The communication control unit 230 to which the master unit switching signal has been transmitted controls the communication unit 105 to transmit and receive packets for releasing the relationship with all the registered slave units. As a result, the communication terminal device 10 releases the relationship with the slave units registered in the own device (step S37).

[0197] When step S37 is executed, the switching unit 232 rewrites the mode identifier 204 to "1" (step S38) and restarts the communication terminal device 10 (step S39).

[0198] When the communication terminal device 10 is restarted by step S39, the communication terminal device 10 returns to step S1. In step S1 executed at this time, the mode identifier 204 is "1". Therefore, the communication terminal device 10 starts in the slave unit operation mode and will be determined as Yes in step S1. In this way, when the coexistence state of the master unit is detected on the network 91, the communication terminal device 10 operating in the master unit operation mode can be switched to the slave unit operation mode if the priority as the master unit is low.

[0199] As described above, the communication terminal device 10 connected to the network 91 and performing data communication with other communication terminal devices 11, 12, 13, 14, 15 (intra-group communication destinations) via the network 91 has a master unit operation mode in which it operates as a master unit and a slave unit operation mode in which it operates as a slave unit. The storage device 101 stores the determination reference information 203, which is a reference for determining the priority of the own device as the master unit, in the setting information 201, which is a reference for switching the operation mode between the master unit operation mode and the slave unit operation mode. A communication partner determination unit 233 determines whether or not the transmission source of the received information is an intra-group communication destination based on the information received by the own device. A master unit monitoring unit 231 monitors whether or not the intra-group communication destination is a master unit according to the determination result by the communication partner determination unit 233 And the master Master unit monitoring unit 23 By 1, Obtain the determination reference information 203 at the intra-group communication destination detected as the master unitIt includes a communication unit 105 Further, when the communication terminal device 10 is operating in the master device operation mode and the master device monitoring unit 231 detects the presence of a master device other than the own device, the communication terminal device 10 further includes a switching unit 232 that switches the master device operation mode of the own device to the slave device operation mode based on the determination reference information 203 of the own device and the determination reference information 203 in the group communication destination detected as the master device by the master device monitoring unit 231.

[0200] Thereby, even when crosstalk occurs while the communication terminal devices 10, 11, and 12 are operating in the master device operation mode, it is possible to prevent the communication terminal device 20 on the network 92 from transitioning to the slave device operation mode by misidentifying it as the master device on the network 91. That is, it is possible to prevent the unintentional elimination of the master device. Therefore, it is possible to prevent the network 91 from being integrated with another network 92 by misidentifying a communication terminal device 20 other than the group communication destination as the master device.

[0201] Also, when the communication terminal device 10 is operating in the slave device operation mode and the master device of the own device is operating in the master device operation mode, the master device monitoring unit 231 monitors whether or not a master device other than the master device of the own device exists among the group communication destinations according to the determination result by the communication partner determination unit 233, and obtains the determination reference information 203 (first determination reference information) that is a reference for determining the priority as the master device of the master device of the own device and the determination reference information 203 (second determination reference information) that is a reference for determining the priority as the master device of a master device other than the master device of the own device. Communication unit 105 And when it is determined by the master device monitoring unit 231 that a master device other than the master device of the own device exists, based on the first determination reference information and the second determination reference information, either the master device of the own device or a master device other than the master device of the own device is determined as the master device for the own device.

[0202] As a result, even when crosstalk occurs while the communication terminal devices 10, 11, 12, 13, 14, 15 are operating in the slave operation mode, it is possible to prevent the communication terminal device 20 on the network 92 from being misidentified as the master device (a master device other than its own master device) on the network 91 and thus from detaching from its own master device. Therefore, by misidentifying the communication terminal device 20 other than the in-group communication destination as the master device, it is possible to prevent the network 91 from being integrated with another network 92.

[0203] In addition, the storage device 101 of the communication terminal devices 10, 11, 12, 13, 14, 15 stores terminal identification information 211 for individually identifying other communication terminal devices (in-group communication destinations). The communication partner determination unit 233 determines whether the transmission source of the received information is an in-group communication destination according to whether the identification information for identifying the transmission source included in the received information is included in the terminal identification information 211 stored in the storage device 101. Thereby, it is possible to easily determine whether the transmission source is an in-group communication destination.

[0204] In the above description, the master device with the smaller determination reference information 203 (MAC address) is determined to have a higher priority as the master device. However, the master device with the larger determination reference information 203 (MAC address) may be determined to have a higher priority as the master device.

[0205] Also, in the above description, it was explained that when starting up as a slave device, the slave device executes step S5. That is, the procedure in which the communication partner determination unit 233 of the slave device performs the authentication as to whether the discovered master device is a communication destination within the group was explained. However, the authentication as to whether it is a communication destination within the group may be performed by the master device. For example, when starting up, the slave device transmits a registration request including the determination reference information 203 (its own MAC address) in step S2. The communication partner determination unit 233 of the master device that has received this registration request may be configured to permit registration only when the slave device is a communication destination within the group by collating with the terminal identification information 211. When obtaining such permission, the slave device may be configured to determine Yes assuming that the master device exists in step S2.

[0206] <2. Second Embodiment> In the first embodiment, according to the terminal identification information 211, it was determined whether the transmission source of the information received from the master device (master device information 202) is a communication destination within the group. However, the information for determining whether the transmission source of the received information is a communication destination within the group is not limited to these pieces of information.

[0207] FIG. 11 is a diagram showing the functional blocks included in the communication terminal device 16 in the second embodiment together with the data flow. The communication terminal device 16 in the second embodiment is different from the communication terminal device 10 in the first embodiment in that it includes a communication partner determination unit 234 instead of the communication partner determination unit 233. In the following description, among the configurations of the communication terminal device 16, the same configurations as those of the communication terminal device 10 are denoted by the same reference numerals, and the description will be omitted as appropriate. However, strictly speaking, the program 200 in the first embodiment and the program 200 in the second embodiment are not the same, but the same reference numerals are used for explanation.

[0208] The storage device 101 in the second embodiment stores setting information 209 different from the setting information 201. The setting information 209 is different from the setting information 201 in that it includes master device candidate identification information 212 instead of the terminal identification information 211.

[0209] The parent unit candidate identification information 212 is identification information (MAC addresses) of the communication terminal devices 10, 11, and 12 that have a parent unit operation mode and have the potential to operate as a parent unit for intra-group communication destinations within the network 91. Specifically, the terminal identification information 211 was "10, 11, 12, 13, 14, 15," while the parent unit candidate identification information 212 is "10, 11, 12."

[0210] The communication partner determination unit 234 is a functional block realized by the CPU 100 operating in accordance with the program 200. In a situation where the communication partner determination unit 233 refers to the terminal identification information 211, the communication partner determination unit 234 refers to the parent device candidate identification information 212 instead of the terminal identification information 211.

[0211] The communication partner determination unit 233 refers to the terminal identification information 211 when it uses the identification information (information indicating any of the parent devices in the communication destination within the group) acquired from the parent device information 202. Therefore, the identification information of the communication terminal devices 13, 14, and 15 that do not operate as parent devices is increased in the terminal identification information 211.

[0212] In contrast, the communication partner determination unit 234 refers to the master device candidate identification information 212, so that the amount of information stored in the storage device 101 can be reduced.

[0213] As described above, the storage device 101 of the communication terminal device 16 in the second embodiment stores the master unit candidate identification information 212 for individually identifying the master unit candidates among the other communication terminal devices (communication destinations within the group). To 212 The communication terminal device 200 further includes a communication destination determination unit 234 that determines whether the sender of the received information is an intra-group communication destination, depending on whether the received information contains identification information for identifying the sender. This makes it possible to reduce the amount of information to be stored, compared to storing all the identification information of other communication terminal devices.

[0214] <3. Third Embodiment> In the above embodiment, according to the terminal identification information 211 or the master device candidate identification information 212, it was determined whether the transmission source of the information received from the master device (master device information 202) is a communication destination within the group. However, the information for determining whether the transmission source of the received information is a communication destination within the group is not limited to these pieces of information.

[0215] FIG. 12 is a diagram showing the functional blocks included in the communication terminal device 17 in the third embodiment together with the data flow. The communication terminal device 17 in the third embodiment is different from the communication terminal device 16 in the second embodiment in that it includes a communication partner determination unit 235 instead of the communication partner determination unit 234. In the following description, among the configurations of the communication terminal device 17, the same configurations as those of the communication terminal device 16 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. However, strictly speaking, the program 200 in the second embodiment and the program 200 in the third embodiment are not the same, but they will be described using the same reference numerals.

[0216] The storage device 101 in the third embodiment stores setting information 210 different from the setting information 209. The setting information 210 is different from the setting information 209 in that it includes group identification information 213 instead of the master device candidate identification information 212.

[0217] The group identification information 213 is information for identifying other communication terminal devices from communication terminal devices in other groups. The value of the group identification information 213 in the third embodiment is "1".

[0218] The value of the upper digit (tens digit) of the identification information (MAC address) of the communication terminal devices 10, 11, 12 that are communication destinations within the group in the network 91 is "1". On the other hand, the value of the upper digit (tens digit) of the identification information (MAC address) of the communication terminal device 20 in another group is "2". Therefore, if "1" is stored as the group identification information 213, it is possible to determine whether the transmission source of the received information is the communication terminal devices 10, 11, 12.

[0219] The communication partner determination unit 235 is a functional block realized by the CPU 100 operating according to the program 200. In a situation where the communication partner determination unit 234 refers to the parent device candidate identification information 212, the communication partner determination unit 235 refers to the group identification information 213 instead of the parent device candidate identification information 212. Then, it determines whether the tens digit of the MAC address of the transmission source of the received information matches "1" of the group identification information 213.

[0220] In this way, by storing, as the group identification information 213, information that is common among the communication destinations within the group and different among the communication destinations of different groups, the amount of information to be stored in the storage device 101 can be suppressed. External communication for the program

[0221] As described above, the storage device 101 of the communication terminal device 17 in the third embodiment stores the group identification information 213 for identifying other communication terminal devices (communication destinations within the group) from the communication terminal devices of other groups. Then, the communication terminal device 17 includes a communication partner determination unit 235 that determines whether the transmission source of the received information is a communication destination within the group by collating the group identification information 213 stored in the storage device 101 with the identification information for identifying the transmission source included in the received information. Thereby, compared with the case of storing the identification information regarding a plurality of communication terminal devices, the amount of information to be stored can be suppressed.

[0222] <4. Modification Example> Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible.

[0223] For example, each step shown in the above embodiment is merely an example and is not limited to the order and content shown above. That is, the order and content may be changed as appropriate as long as the same effect can be obtained.

[0224] ​Also, the functional blocks (for example, the master unit monitoring unit 231 and the switching unit 232) shown in the above embodiments have been described as being realized software-wise by the CPU 100 operating according to the program 200. However, some or all of these functional blocks may be configured with dedicated logic circuits and realized hardware-wise.

[0225] Also, the numerical value that becomes the determination reference information 203 is not limited to the above embodiments. For example, it may be the worst value of the communication quality of the slave units registered in the network to which the own unit belongs. In this case, the priority as the master unit with the smaller numerical value of the determination reference information 203 is determined to be higher. Thereby, since the one with the larger worst value of the communication quality can be switched to the slave unit operation mode, the worst value of the communication quality in the finally constructed network 91 can be suppressed. Note that as the communication quality, the number of retry times, the noise level, the communication speed, etc. can be appropriately collected and adopted. Also, these may be appropriately weighted and then determined.

[0226] Alternatively, the time elapsed since the master unit in the network to which the own unit belongs started operating as the master unit may be used as the determination reference information 203. In this case, it is preferable to determine that the priority as the master unit with the larger numerical value of the determination reference information 203 is higher. Thereby, the one with the smaller elapsed time can be switched to the slave unit operation mode, and the master unit that is already operating stably as the master unit can be preferentially maintained.

[0227] Also, alternatively, the manufacturing date of the communication terminal device may be used as the determination reference information 203. In that case, it is preferable to configure it so that the priority of the communication terminal device with the newer manufacturing date is higher. Generally, a newer communication terminal device has a lower risk of failure than an older one. Therefore, by preferentially leaving the communication terminal device with the newer manufacturing date as the master unit, the more important master unit can be stabilized compared to the slave unit.

[0228] Also, in the above embodiment, when it is detected that a plurality of master devices exist simultaneously, it has been described that any one of the master devices switches to a slave device. However, the trigger for the master device to switch to a slave device is not limited to this. For example, when there is a risk of performance degradation of the communication terminal device 10 operating in the master device operation mode, such as an increase in the retry count of the communication terminal device 10, the communication terminal device 10 may switch its own operation mode to the slave device operation mode. That is, the minimum performance may be set as the threshold value and stored as the setting information 201, and the actual performance value may be compared with the threshold value to switch the operation mode. Alternatively, the period and order of operating as the master device may be stored as the setting information 201, and when the period has elapsed, the master device may switch itself to the slave device operation mode. That is, the master device may be in a so-called rotation system. Even in such a configuration, when the device itself is the master device, it can determine the propriety of being the master device of the device itself and automatically switch to the slave device operation mode. Therefore, it is possible to suppress the inappropriate master device from continuing to exist as the master device.

Description of Signs

[0229] 1 Information and communication system 10,11,12,13,14,15,16,17,20,21,30,31 Communication terminal device 100 CPU 101 Storage device 102 Operation unit 103 Display unit 104 Timer unit 105 Communication unit 200 Program 201,209,210 Setting information 202 Master device information 203 Judgment criterion information 204 Mode identifier 205 Monitoring permission flag 206 Switching permission flag 207 Standby time 208 Blacklist 211 Terminal identification information 212 Master device candidate information 213 Group identification information 230 Communication control unit 231 Master unit monitoring unit 232 Switching unit 233, 234, 235 Communication partner determination unit 91, 92, 93 Network

Claims

1. A communication terminal device connected to a network and performing data communication with communication destinations within a group via the network, having a master unit operation mode that operates as a master unit and a slave unit operation mode that operates as a slave unit, a storage means for storing appropriate information serving as a criterion for switching the operation mode between the master unit operation mode and the slave unit operation mode, including determination criterion information serving as a criterion for determining the priority of the own device as a master unit; a communication partner determination means for determining, based on the information received by the own device, whether the transmission source of the received information is a communication destination within the group; a master unit monitoring means for monitoring whether the communication destination within the group is a master unit according to the determination result by the communication partner determination means; an acquisition means for acquiring the determination criterion information at the communication destination within the group detected as a master unit by the master unit monitoring means; when the own device is operating in the master unit operation mode, if the master unit monitoring means detects the presence of a master unit other than the own device, based on the determination criterion information of the own device and the determination criterion information at the communication destination within the group detected as a master unit by the master unit monitoring means, while switching the master unit operation mode of the own device to the slave unit operation mode, if the master unit monitoring means does not detect the presence of a master unit other than the own device, a switching means for ignoring without switching the master unit operation mode of the own device to the slave unit operation mode; A communication terminal device comprising the above.

2. The communication terminal device according to claim 1, wherein the storage means stores terminal identification information for individually identifying the communication destinations within the group, and the communication partner determination means determines whether the transmission source of the received information is a communication destination within the group according to whether the identification information for identifying the transmission source included in the received information is included in the terminal identification information stored in the storage means. A communication terminal device.

3. The communication terminal device according to claim 1, wherein the storage means stores master unit candidate identification information for individually identifying master unit candidates among the communication destinations within the group, and the communication partner determination means determines whether the transmission source of the received information is a communication destination within the group according to whether the identification information for identifying the transmission source included in the received information is included in the master unit candidate identification information stored in the storage means. A communication terminal device.

4. The communication terminal device according to claim 1, The memory means stores group identification information for identifying the in-group communication destination from communication terminal devices of other groups. The communication partner determination means is a communication terminal device that determines whether the transmission source of the received information is the in-group communication destination by collating the group identification information stored in the memory means with the identification information for identifying the transmission source included in the received information.

5. A communication terminal device connected to a network and performing data communication with an in-group communication destination via the network, having a slave operation mode in which it operates as a slave unit, communication partner determination means for determining whether the transmission source of the received information is the in-group communication destination based on the information received by the own device, parent device monitoring means for monitoring whether a second parent device other than the first parent device exists among the in-group communication destinations when operating in the slave operation mode and when the first parent device to which the own device is registered is operating in a parent operation mode in which it operates as a parent device, according to the determination result by the communication partner determination means, acquisition means for acquiring first determination reference information serving as a reference for determining the priority of the first parent device as a parent device and second determination reference information serving as a reference for determining the priority of the second parent device as a parent device, comprising: When it is determined by the parent device monitoring means that the second parent device exists, based on the first determination reference information and the second determination reference information, either the first parent device or the second parent device is determined as the parent device for the own device, while when the parent device monitoring means does not detect the existence of the second parent device, the first parent device is maintained. A communication terminal device.

6. An information communication system comprising a plurality of communication terminal devices connected to a network, wherein the communication terminal device has a parent operation mode in which it operates as a parent device and a slave operation mode in which it operates as a slave unit, memory means for storing, in appropriate information serving as a reference for switching the operation mode between the parent operation mode and the slave operation mode, determination reference information serving as a reference for determining the priority of the own device as a parent device, communication partner determination means for determining whether the transmission source of the received information is the in-group communication destination among the plurality of communication terminal devices based on the information received by the own device, parent device monitoring means for monitoring whether the in-group communication destination is a parent device according to the determination result by the communication partner determination means. An acquisition means for acquiring determination reference information in the group communication destination detected as the master device by the master device monitoring means; When the own device is operating in the master device operation mode and the master device monitoring means detects the presence of a master device other than the own device, based on the determination reference information of the own device and the determination reference information in the group communication destination detected as the master device by the master device monitoring means, while switching the master device operation mode of the own device to the slave device operation mode, when the master device monitoring means does not detect the presence of a master device other than the own device, a switching means for ignoring without switching the master device operation mode of the own device to the slave device operation mode; An information communication system comprising the same.

7. A computer-readable program executed by a computer connected to a network and performing data communication with a group communication destination via the network, wherein the execution of the program by the computer causes the computer to Have a master device operation mode in which it operates as a master device and a slave device operation mode in which it operates as a slave device; Storage means for storing, in appropriate information serving as a criterion for switching the operation mode between the master device operation mode and the slave device operation mode, determination reference information serving as a criterion for determining the priority of the own device as a master device; Communication partner determination means for determining whether or not the transmission source of the received information is the group communication destination based on the information received by the own device; Master device monitoring means for monitoring whether or not the group communication destination is a master device according to the determination result by the communication partner determination means; An acquisition means for acquiring determination reference information in the group communication destination detected as the master device by the master device monitoring means; When the own device is operating in the master device operation mode and the master device monitoring means detects the presence of a master device other than the own device, based on the determination reference information of the own device and the determination reference information of the group communication destination detected as the master device by the master device monitoring means, while switching the master device operation mode of the own device to the slave device operation mode, when the master device monitoring means does not detect the presence of a master device other than the own device, a switching means for ignoring without switching the master device operation mode of the own device to the slave device operation mode; A program for functioning as a communication terminal device comprising the same.

8. A readable program by a computer connected to a network and performing data communication with an in-group communication destination via the network, wherein the execution of the program by the computer causes the computer to have a slave operation mode that operates as a slave unit, communication partner determination means for determining whether or not the transmission source of the received information is the in-group communication destination based on the information received by the own unit; parent unit monitoring means for monitoring whether or not a second parent unit other than the first parent unit exists among the in-group communication destinations according to the determination result by the communication partner determination means when operating in the slave operation mode and when the first parent unit registered in the own unit operates in a parent operation mode that operates as a parent unit; acquisition means for acquiring first determination reference information serving as a reference for determining the priority of the first parent unit as a parent unit and second determination reference information serving as a reference for determining the priority of the second parent unit as a parent unit; comprising a program that functions as a communication terminal device that, when it is determined by the parent unit monitoring means that the second parent unit exists, determines either the first parent unit or the second parent unit as the parent unit for the own unit based on the first determination reference information and the second determination reference information, and maintains the first parent unit when the parent unit monitoring means does not detect the existence of the second parent unit.

9. An information communication method by a plurality of communication terminal devices having a parent operation mode that operates as a parent unit and a slave operation mode that operates as a slave unit, for each of the plurality of communication terminal devices, a step of storing, in appropriate information serving as a reference for switching an operation mode between the parent operation mode and the slave operation mode, determination reference information serving as a reference for determining the priority of the own unit as a parent unit; a step of determining by communication partner determination means whether or not the transmission source of the received information is an in-group communication destination among the plurality of communication terminal devices based on the information received by the communication terminal device; a step of monitoring whether or not the in-group communication destination is a parent unit according to the determination result by the communication partner determination means in the communication terminal device; a step of acquiring determination reference information in the in-group communication destination detected as a parent unit; When the communication terminal device is operating in the master device operation mode and the master device is detected from the communication destination within the group, based on the determination reference information of the communication terminal device and the determination reference information of the communication destination within the group detected as the master device, while switching the master device operation mode of the communication terminal device to the slave device operation mode, when the presence of the master device that is the communication destination within the group is not detected, a step of ignoring without switching the master device operation mode of the communication terminal device to the slave device operation mode; An information communication method having the above.

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