JP2010273275A - Power line communication apparatus, method thereof, and power line communication network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power line communication (PLC) apparatus, a method thereof and a PLC network in which an interference caused between PLC networks is suppressed and a frequency band to be used for PLC is not limited. <P>SOLUTION: Each of PLC apparatuses 1, 2 includes: a PLC section 14 for exchanging a communication signal according to a PLC system; a command notification section 122 for transmitting, when the present machine is a master station 1, from the PLC section 14 to the other PLC apparatus a command communication signal for adjusting a transmission output level of the other PLC apparatus; and a communication control section 141 for controlling, when the command communication signal is received by the PLC section 14, a transmission output level of the PLC section 14 to transmit the communication signal with such minimum communication quality as to communicate with the other PLC apparatus 1, 2 being adjacent on communication. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power line carrier communication apparatus and a power line carrier communication method for performing communication by power line carrier communication using a power line used for power supply as a transmission path, and in particular, a parent power line carrier communication apparatus as a parent station and a slave station. The present invention relates to a power line carrier communication apparatus and a power line carrier communication method which are preferably used in a plurality of communication networks including one or a plurality of child power line carrier communication apparatuses. The present invention also relates to a power line carrier communication network including such a parent power line carrier communication device and one or more child power line carrier communication devices.

  In recent years, networking has progressed in various technical fields due to advances in communication technology, and various electrical devices (including electronic devices, the same applies hereinafter) in buildings are being connected to communication networks. In this networking, there is an advantage that it is not necessary to install a new transmission line because the existing wiring is used, and the initial cost associated with the introduction is accordingly low, and the aesthetics of the building are not impaired. Therefore, power line communication (Power Line Communication, hereinafter abbreviated as “PLC”) using a power line for supplying power to these electric devices as a transmission line has been actively researched and developed. This PLC is a communication system that generally performs transmission and reception by superimposing a PLC communication signal having a frequency higher than the commercial frequency on the power waveform of the commercial power supply. In recent years, relaxation of PLC-related laws and regulations has been studied for the purpose of enabling high-speed communication such as the Internet, and in addition to the frequency band of 10 kHz to 450 kHz that can be used with conventional PLCs, The use of a frequency band of 2 MHz to 30 MHz is considered, and the PLC is a PLC using a high-speed PLC that performs PLC using a communication signal of a frequency band of 2 MHz to 30 MHz and a communication signal of a frequency band of 10 kHz to 450 kHz. A low speed PLC is known.

  When networking using such a PLC, for example, a parent power line carrier communication device (hereinafter abbreviated as “master unit”) as a parent station and one or more child power line carriers as slave stations. In some cases, a power line carrier communication network (hereinafter abbreviated as “PLC network”) is constructed by a master-slave system including a communication device (hereinafter abbreviated as “child device”). Is, for example, a building (for example, an office building, a commercial building, an apartment house, and a detached house) or a predetermined division in one building (for example, a floor and an individual physical unit of an apartment house, for example, a department and a group, etc.) A set defined by a predetermined attribute) or the like. When a plurality of such PLC networks are constructed, communication in one PLC network may interfere with communication in one or a plurality of PLC networks due to the characteristics of the PLC, and countermeasures are desired.

  For example, the power line communication device disclosed in Patent Document 1 is a power line communication device that uses a power line as a signal transmission path, and has a frequency band that causes interference with other power line communication network groups connected to a common power line. Control means is provided for controlling the transmission signal so that the signal level is lower than the signal level of the other frequency band in the transmission signal (paragraph 0012). More specifically, the power line communication device disclosed in Patent Document 1 performs communication using an orthogonal frequency division multiplexing system using a plurality of carriers (carrier waves) in a frequency band for PLC of 2 MHz to 30 MHz (0043 paragraph), By increasing or decreasing the signal level for each carrier wave, the signal level in the frequency band (carrier wave) that causes interference with other power line communication network groups is transmitted to be lower than the signal level in the other frequency band in the transmission signal. It controls the signal (paragraphs 0049, 0057 and 0062). Alternatively, a frequency band (carrier wave) that receives interference from another power line communication network group is not used in communication within the own power line communication network group (paragraph 0081). Each power line communication network group communicates using mutually overlapping frequency bands (paragraph 0044).

  The power line communication apparatus having such a configuration can avoid interference by reducing the signal level of the transmission signal for the frequency band that may cause interference to other network groups, compared to the frequency band that may cause interference, Since the signal level can be made relatively high for other frequency bands, the signal level as a whole can be made relatively high, and the deterioration of the communication quality within the own network group can be suppressed (paragraph 0013). And in Patent Document 1. Each of these paragraph numbers is a paragraph number in Patent Document 1 and is a reference location in each of the above descriptions.

JP 2007-258908 A

  By the way, in the power line communication apparatus disclosed in Patent Document 1, as described above, the signal level in the frequency band causing interference with other power line communication network groups is higher than the signal level in the other frequency band in the transmission signal. A frequency band that is controlled to be lower or that receives interference from another power line communication network group is not used in communication within the own power line communication network group. For this reason, there is a possibility that limited frequency resources allocated for power line carrier communication may not be used effectively. In addition, when the frequency band that causes interference with other power line communication network groups covers substantially the entire frequency band used for power line carrier communication, communication within the own power line communication network group cannot be performed. End up.

  The present invention has been made in view of the above circumstances, and the object thereof is to suppress interference generated between power line carrier communication networks, and the frequency band used for power line carrier communication is not limited. A power line carrier communication apparatus and a power line carrier communication method are provided. And this invention is providing the power line carrier communication network provided with such a power line carrier communication apparatus as a main | base station and a machine.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, the power line carrier communication apparatus according to one aspect of the present invention includes a communication unit that transmits and receives communication signals using the power line carrier communication method, and a transmission output to other power line carrier communication apparatuses when the own device is a master station. A command notification unit that transmits a command communication signal for adjusting a level from the communication unit, and a command communication signal received by the communication unit, the minimum communication capable of communicating with other adjacent power line carrier communication devices And a communication control unit that controls a transmission output level of the communication unit so as to transmit the communication signal with communication quality. A power line carrier communication system according to another aspect of the present invention is a power line carrier communication network including a parent power line carrier communication device that is a parent station and one or more child power line carrier communication devices that are slave stations. Communication method for transmitting and receiving communication signals by power line carrier communication method, using the power line carrier communication method, when the own device is the master station A command notification step transmitted from the communication unit, and when the communication unit receives a command communication signal, the communication signal is transmitted with a minimum communication quality capable of communicating with another power line carrier communication device adjacent on the communication. And a communication control step for controlling a transmission output level of the communication unit.

  In the power line carrier communication device and the power line carrier communication method having such a configuration, when the own device is a master station, a command communication signal for adjusting the transmission output level is transmitted to the other power line carrier communication device. When the command communication signal is received, the minimum communication quality that can be communicated with other power line carrier communication devices (adjacent nodes) that are adjacent to each other regardless of whether the device is a master station or a slave station The transmission output level of the communication unit is controlled so as to transmit the communication signal. Thus, since the transmission output level of the communication unit is controlled to a level at which communication with an adjacent node is possible, interference occurring between the power line carrier communication networks can be suppressed. Moreover, the transmission output level is not simply adjusted to prevent interference between the power line carrier communication networks, but the transmission output level is appropriately adjusted so as to ensure the communication quality at the communication with the adjacent node at a predetermined level. Is done. And since the transmission output level of a communication part is only controlled in this way, the frequency band used for power line carrier communication is not restricted.

  According to another aspect, in the above power line carrier communication device, the other power line carrier communication device to which the command communication signal is transmitted by the command notification unit is a power line carrier communication formed by a plurality of power line carrier communication devices. In the case where a plurality of groups that are classified according to logical communication availability are formed on the network, the network belongs to another group different from the group to which the own device belongs.

  In such a configuration, the parent power line carrier communication device (parent device) that is the parent station is summarized only in the communication route to the child power line carrier communication device (child device) of the group to which the own device belongs, and the communication route is The storage capacity for storing can be reduced. In addition, since the transmission output level is adjusted in another group different from the group to which the own device belongs, interference occurring between the power line carrier communication networks while maintaining the communication state of the group to which the own device belongs. Can be suppressed.

  According to another aspect, in the above-described power line carrier communication device, another power line carrier communication device adjacent on the communication is a slave station.

  In such a configuration, the above-described transmission output level is adjusted between the parent power line carrier communication device (master device) as the master station and the child power line carrier communication device (slave device) as the child station. It becomes possible.

  Further, in another aspect, in the above power line carrier communication device, the other power line carrier communication devices adjacent on the communication are a power line carrier communication network composed of a plurality of power line carrier communication devices. When the communication route between the nodes is represented in a graph with a tree structure with the parent station as the root, it is a slave station in the first hierarchy that is the next hierarchy of the parent station.

  In such a configuration, the above-described transmission output level is adjusted only between the master station and the first-layer slave station (first terminal station), so the above-described transmission output level for the entire power line carrier communication network is adjusted. It is possible to reduce the load associated with the adjustment. Here, the tree structure with the parent station as the root of the communication route between the parent station and the child station includes a tree structure of only the root and the first layer.

  Further, in another aspect, in the above-described power line carrier communication device, the other power line carrier communication device to which the command communication signal is transmitted by the command notification unit is a master station. .

  In such a configuration, a command communication signal is transmitted to a master station belonging to another group, and the above-described transmission output level is adjusted between the own apparatus and the master station belonging to another group. As a result, in such a configuration, the communication route of the other master station is deleted, and the storage capacity for storing the communication route can be reduced. Further, in such a configuration, the command communication signal is transmitted to the master station belonging to another group, and the above-mentioned transmission output level adjustment in the other group can be executed by the master station of the group. It becomes possible to reduce the load.

  In another aspect, in the above-described power line carrier communication device, a transformer is interposed between the own device and another power line carrier communication device to which the command communication signal is transmitted by the command notification unit. It is characterized by that.

  The power line communication device disclosed in Patent Document 1 is a device used in a communication network in which each power line (branch line) that is branched directly from one power line (trunk line) is used as a communication transmission path. There is a countermeasure against interference generated through the trunk line. In the configuration according to the other aspect described above, a transformer is interposed between the own device and another power line carrier communication device to which the command communication signal is transmitted by the command notification unit, and between the power line carrier communication networks via the transformer. Can also suppress interference.

  Further, in another aspect, in the above-described power line carrier communication device, the communication control unit includes a level adjustment unit that controls a transmission output level of the communication signal, And a level control unit that controls the level adjusting unit so as to transmit the communication signal with a minimum communication quality capable of communicating with another adjacent power line carrier communication device.

  In such a configuration, it is possible to provide a power line carrier communication device including a communication control unit including a level adjustment unit and a level control unit.

  According to another aspect, in the above power line carrier communication apparatus, the level adjustment unit is an attenuator that attenuates an input level and outputs the attenuated input signal at a predetermined output level.

  In such a configuration, the level adjustment unit is configured by an attenuator, and the level adjustment unit can be configured relatively easily.

  According to another aspect, in the power line carrier communication device described above, the level adjusting unit is a coupling circuit that uses a transformer capable of selecting a plurality of winding ratios and is communicably connected to the power line. And

  In such a configuration, it is possible to incorporate a level adjustment unit in the coupling circuit by using a transformer capable of selecting a plurality of winding ratios.

  According to another aspect, in the above power line carrier communication device, the level adjustment unit amplifies a communication signal to be transmitted by using an operational amplifier capable of selecting a plurality of feedback resistance ratios at a predetermined output level. It is an amplifier which outputs.

  In such a configuration, by using an operational amplifier capable of selecting a plurality of feedback resistance ratios, it becomes possible to incorporate a level adjusting unit in the amplifier.

  In another aspect of the present invention, in a power line carrier communication network including a parent power line carrier communication device as a parent station and one or more child power line carrier communication devices as slave stations, the parent power line The carrier communication device is any one of these power line carrier communication devices described above.

  With such a configuration, it is possible to suppress interference generated between the power line carrier communication networks, and to provide a power line carrier communication network in which the frequency band used for power line carrier communication is not limited.

  The power line carrier communication apparatus, the power line carrier communication method, and the power line carrier communication network according to the present invention can suppress interference generated between the power line carrier communication networks, and the frequency band used for the power line carrier communication is not limited.

It is a figure which shows the structure of the power line carrier communication network in embodiment. It is a block diagram which shows the structure of the power line carrier communication apparatus in embodiment. It is a figure which shows the structure of the route table in the power line carrier communication apparatus of embodiment. It is a sequence diagram which shows adjustment operation | movement of the transmission output level in the power line carrier communication network of embodiment. It is a figure which shows the route table between parents before and after the transmission output level adjustment of the main | base station 1-1. It is a figure which shows the route table between parents before and after transmission output level adjustment of the main | base station 1-2. It is a block diagram which shows the structure of the power line carrier communication apparatus in the 1st aspect of embodiment. It is a block diagram which shows the structure of the power line carrier communication apparatus in the 2nd aspect of embodiment. It is a block diagram which shows the structure of the power line carrier communication apparatus in the 3rd aspect of embodiment. It is a block diagram which shows the structure of the power line carrier communication apparatus in the 4th aspect of embodiment.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably.

  FIG. 1 is a diagram illustrating a configuration of a power line carrier communication network in the embodiment. FIG. 2 is a block diagram illustrating a configuration of the power line carrier communication device according to the embodiment. FIG. 3 is a diagram illustrating a configuration of a route table in the power line carrier communication apparatus according to the embodiment. FIG. 3A shows a route table before adjustment of the transmission output level, and FIG. 3B shows a route table after adjustment of the transmission output level.

  In FIG. 1, the power line carrier communication network (hereinafter abbreviated as “PLC network”) NT in the present embodiment is, for example, a building (for example, an office building, a commercial building, an apartment house, a detached house, etc.) or a predetermined in one building. (For example, a certain physical area such as floors and apartments of a housing complex, or a set defined by a predetermined attribute such as a department and a group), etc. A plurality of power line carrier communications that are connected to a main power line L (LA, LS) and perform power line carrier communications (hereinafter abbreviated as “PLC”) using a predetermined communication protocol using the power line L as a transmission line. The apparatus (henceforth abbreviated as "PLC apparatus") 1 and 2 is comprised.

  The power line L includes a trunk line LA laid in the building, and one or a plurality of branch lines LS branched from the trunk line LA. In the example illustrated in FIG. 1, the branch line LS includes three branch lines LS-1, LS-2, and LS-3.

  In the present specification, when referring generically, it is indicated by a reference symbol without a suffix, and when referring to an individual configuration, it is indicated by a reference symbol with a suffix.

  The PLC network NT includes one or more parent PLC devices (hereinafter abbreviated as “parent device”) 1 as a parent station and one or more PLC devices (hereinafter referred to as “child devices” as child stations). 2). In the example shown in FIG. 1, the PLC network NT is formed with three groups G-1, G-2, and G-3, which are divided according to logical communication availability. Machines 1-1, 1-2, and 1-3 are provided. Each of these three master units 1-1, 1-2, and 1-3 is connected to the trunk line LA via respective transformers TrA-1, TrA-2, and TrA-3. As described above, two transformers TrA are interposed between the parent devices 1-1, 1-2, and 1-3. For example, two transformers TrA-1 and TrA-2 are interposed between the master unit 1-1 and the master unit 1-2.

  Note that the transformer TrA used between the PLC devices 1 is more specifically a so-called transformer, and transformers such as coupling transformers TrB and TrC used in the PLC devices 1 and 2 to be described later are more Specifically, it is a so-called communication transformer.

  Each group G-1, G-2, G-3 includes one or a plurality of slave units 2-1, 2-2, 2-3. Each of the one or a plurality of slave units 2-1, 2-2, and 2-3 is connected to each of the transformers TrA-1, TrA-2, and TrA-3, or each of the transformers TrA-1, TrA-2. , TrA-3 and each parent device 1-1, 1-2, 1-3, respectively, to each branch line L-1, L-2, L-3 branched from the trunk line LA, directly or through an outlet Each is connected.

  FIG. 1 shows a physical connection state of the PLC network NT, and three logical groups are formed in the PLC network NT as described above. The first group G-1 includes a parent device 1-1 and one or more child devices 2-1, and the second group G-2 includes a parent device 1-2 and one or more child devices 2. -2 and the third group G-3 includes a parent device 1-3 and one or more child devices 2-3. Master unit (PLC device of master station, master PLC device) 1 has a function of controlling and controlling communication in own PLC network NT to which host device 1 belongs, and slave unit (PLC device of slave station, slave PLC device) ) 2 has a function of performing communication within the own PLC network NT according to the overall control of the base unit 1.

  If the PLC network NT of such a structure gives a more specific example, it will be constructed | assembled in an apartment house, the group G will be formed for every floor, and the subunit | mobile_unit 2 will be each arrange | positioned at each dwelling unit. The subunit | mobile_unit 2 is provided with a predetermined sensor, for example, the subunit | mobile_unit 2 transmits the detected value detected with the said sensor to the main | base station 1, and the main | base station 1 respond | corresponds the detected value of the said sensor for every subunit | mobile_unit 2. It is memorized and managed. This PLC network NT can be suitably applied to a remote monitoring system using such a PLC. Such a remote monitoring system is, for example, a security system for protecting the safety of each dwelling unit, such as intruder detection or fire detection, for example, the amount of water used by a water meter or the use of a wattmeter. Examples include a meter reading system that measures the amount of power. The PLC network NT may be configured such that the parent device 1 further controls the child device 1, and may constitute a remote monitoring control system that remotely monitors and controls devices such as home appliances, for example.

  The PLC devices 1 and 2 used in the PLC network NT including such a parent PLC device 1 as a parent station and one or more child PLC devices 2 as child stations are, for example, as shown in FIG. The storage unit 11, the control unit 12, the parent-child setting unit 13, and the power line carrier communication unit (hereinafter abbreviated as “PLC unit”) 14.

  In FIG. 2, in the present embodiment, the same device is used for the parent device 1 and the child device 2. For example, the PLC devices 1 and 2 have their own devices 1 and 2 as the parent device (the PLC device of the parent station). ) In the parent-child setting unit 13 for setting whether to function as 1 or as a slave device (slave station PLC device) 2, it functions as the master device 1 when set to “parent”. ”To function as the slave unit 2. The parent / child setting unit 13 includes, for example, a jumper switch, a changeover switch, and the like, and is configured so that the control unit 12 can acquire the setting state.

  In this embodiment, the same device provided with such a parent-child setting unit 13 is used for the parent device 1 and the child device 2, but the parent device 1 may be a device dedicated to the parent station. The slave unit 2 may be a device dedicated to the slave station.

  The storage unit 11 functionally includes a route table storage unit 111 that stores information about communication routes, and each program such as a control program for operating the PLC devices 1 and 2 and information necessary for executing each program. And so-called working memory for the control unit 12. The storage unit 11 stores each program, information necessary for the program, and the like. For example, a nonvolatile storage element such as a ROM (Read Only Memory) or a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory). A storage element and a volatile storage element such as a RAM (Random Access Memory) serving as a working memory are provided. The storage unit 11 includes a group name to which the own devices 1 and 2 belong, an identifier unique to the own devices 1 and 2 for identifying and identifying the own devices 1 and 2, and is used as a communication address in this embodiment. ID to be stored is stored by the initial setting. This ID is one or a plurality of code strings. For example, a node address of the data link layer is used. In the present embodiment, each PLC device 1 and 2 is assigned an integer as a serial number as the ID.

  The route table storage unit 111 is an area for storing information on communication routes in a table format, for example. When the PLC devices 1 and 2 are the parent device 1, the route table storage unit 111 registers a route table (communication route table) for registering all communication routes for each child device 2 within a predetermined range in the PLC network NT. , Routing table). On the other hand, when the PLC devices 1 and 2 are the slave units 2, the route table storage unit 111 stores a communication route table for registering a communication route from the own device 2 to the master unit 1. There may be one communication route in the handset 2 or a plurality of communication routes to improve fault tolerance.

  The route table RTB stored in the parent device 1 and the child device 2 has the same structure in this embodiment. For example, as shown in FIG. 3, an ID field for registering the ID of the communication partner in the communication route, ID A group name field for registering a group name for identifying and identifying a group to which the PLC device 1 or 2 of the ID registered in the field (communication partner of communication route) belongs, and an ID registered in the ID field ( Attribute information field for registering attribute information in the PLC device 1 or 2 of the communication partner of the communication route), PLC device 1 of the ID (communication partner of the communication route) registered in the ID field from the own device 1 or 2 A communication route field for registering a communication route up to 2 and a communication quality field for registering the communication quality of the communication route. A record is created for each ID.

  In this embodiment, the attribute information is parent-child type information indicating whether the PLC devices 1 and 2 are the parent device 1 or the child device 2, and the communication partner is the parent device 1 in the attribute information field. In such a case, a code indicating that fact, for example, “parent” is registered, and when the communication partner is the child device 2, a code indicating that fact, for example, “child” is registered. In the communication route field, when the own device 1 or 2 is directly connected to the PLC device 1 or 2 of the communication partner, the ID of the communication partner is directly registered as shown in FIG. When relaying by other PLC devices 1 and 2 is necessary, the IDs of the PLC devices 1 and 2 to be relayed are registered in the relay order. For example, in the group with the group name “A”, when the parent device 1 with ID “1” transmits a communication signal to the child device 2 with ID “5”, the relay of the child device 2 with ID “3” is required. In this case, “3, 5” is registered as a communication route in the communication route field.

  The communication quality (link quality, communication cost) is an evaluation value indicating the degree of goodness of the communication route between the own devices 1 and 2 and the communication partner. For example, the reception level (reception signal strength) of the received communication signal It is a value according to. The communication quality may be a value corresponding to the SN ratio of the received communication signal, may be a value corresponding to the bit error rate of the received communication signal, or may be a packet error of the received signal. It may be a value according to the rate, or may be a value according to a plurality of factors among the reception level, SN ratio, bit error rate, and packet error rate of the received communication signal. Further, in any of the above, the number of hops of the communication route may be taken into consideration.

  The route table RTB of the route table storage unit 111 is configured such that a communication route is automatically constructed by a known communication route construction method such as a routing protocol, or a user such as a constructor constructs a communication route. Is generated and stored in the route table storage unit 111.

  Returning to FIG. 2, the control unit 12 includes, for example, a microprocessor and its peripheral circuits, and controls each unit such as the storage unit 11, the parent-child setting unit 13, the PLC unit 14, and the like according to the function, and this PLC device This is a circuit that controls overall control of 1 and 2. The control unit 12 is functionally configured to include a table processing unit 121, a command notification unit 122, and a relay processing unit 123 in order to optimize the transmission level and perform communication using the PLC method.

  The table processing unit 121 manages the route table RTB stored in the route table storage unit 111 as described later. As will be described later, the command notification unit 122 transmits its output to the other PLC devices 1 and 2 when the parent device 1 is set as the parent device 1 (the master station PLC device 1). A command communication signal for adjusting the level is transmitted from the PLC unit 14. The command communication signal contains command notification information for causing the other PLC devices 1 and 2 to adjust the transmission output level. When the communication signal received by the PLC unit 14 from the power line L needs to be relayed, the relay processing unit 123 transmits the PLC devices 1 and 2 to be transferred next from the own devices 1 and 2 in the communication route (the communication route). Relay processing is performed to transmit the received communication signal (relay signal) to the communication partner PLC devices 1 and 2 in FIG. Note that the PLC devices 1 and 2 may have a configuration in which the relay processing unit 123 is omitted, and the PLC devices 1 and 2 have a communication between the parent device 1 and the plurality of child devices 2 for communication. The present invention is preferably applied to a PLC network NT connected in a star shape.

  The PLC unit 14 is a power line carrier communication system using the power line L (hereinafter abbreviated as “PLC system”) for transmitting and receiving communication signals to and from other PLC devices 1 and 2 using a predetermined communication protocol. It is a communication interface circuit. As described above, the PLC transmits, for example, by superimposing a high-frequency communication signal on the power waveform of the commercial frequency, or by separating and receiving the high-frequency communication signal from the power waveform. This is a communication method for transmitting and receiving communication signals via the network.

  When the PLC unit 14 receives a command communication signal in the PLC unit 14 in order to optimize the transmission signal level as will be described later, the PLC unit 14 can communicate with other PLC devices 1 and 2 adjacent to each other in communication. A communication control unit 141 that controls the transmission output level of the PLC unit 14 is provided so as to transmit PLC communication signals with limited communication quality. For example, as shown in FIG. 2, the communication control unit 141 includes a level adjusting unit 21 that controls a transmission output level of a communication signal, and a parent-child setting unit 13 that is set as the parent device 1. And a level control unit 22 that controls the level adjusting unit 21 so as to transmit a PLC communication signal with a minimum communication quality capable of communicating with other PLC devices 1 and 2 that are adjacent on the communication. .

  Next, the operation of this embodiment will be described.

  First, the command notification unit 122 of the control unit 12 refers to the parent-child setting unit 13 and determines whether the own device is set to the parent device 1 or the child device 2. As a result of the determination, when the own device is set as the child device 2, the command notification unit 122 ends this process. On the other hand, as a result of the determination, when the own device is set as the parent device 1, the command notification unit 122 refers to the route table RTB stored in the route table storage unit 111 of the storage unit 11, and this A command communication signal for adjusting the transmission output level of the PLC devices 1 and 2 (other PLC devices 1 and 2) having an ID registered in the route table RTB is transmitted from the PLC unit 14 to the power line L (command notification). Process).

  When the other PLC devices 1 and 2 receive this command communication signal from the power line L through the PLC unit 14, the communication control unit 14 can communicate with other PLC devices 1 and 2 adjacent in communication in advance. The transmission output level of the PLC unit 14 is controlled so as to transmit the PLC communication signal with the minimum communication quality (communication control step).

  More specifically, the communication control unit 14 searches for other PLC devices 1 and 2 adjacent on the communication by referring to the route table RTB. That is, in the communication route, the PLC devices 1 and 2 that can communicate directly with the own device 1 are searched. Then, the communication control unit 14 sets the searched PLC devices 1 and 2 as communication partners, controls the level adjustment unit 21 by the level control 22, and a communication signal (level adjustment signal) for adjusting the transmission level Is adjusted to the maximum transmission level and transmitted from the PLC unit 14 to the power line L toward the communication partner (level adjustment signal transmission step). In the following description, in order to distinguish between the configuration of the transmission source and the transmission destination of the level adjustment signal, the configuration of the transmission destination is further appended with “rv” for convenience.

  When the PLC devices 1rv and 2rv of the communication counterparts receive this level adjustment signal, the PLC unit 14rv obtains the communication quality of the received level adjustment signal. Then, based on the communication quality, the control unit 12 obtains a transmission output level for transmitting a PLC communication signal with a minimum communication quality communicable with the transmission source PLC device 1, and obtains the obtained transmission. The output level is stored in the storage unit 11rv in association with the ID of the PLC device 1 that is the transmission source. By operating in this way, when the other PLC devices 1rv and 2rv receive this command communication signal from the power line L at the PLC unit 14rv, the communication control unit 14rv communicates with other PLC devices 1 adjacent in communication in advance. It is possible to control the transmission output level of the PLC unit 14rv so as to transmit a PLC communication signal with the minimum communication quality that can be set. In addition, the PLC unit 14rv sets the transmission source of the level adjustment signal as the communication partner and generates a communication signal (level adjustment reply signal) for returning the level adjustment signal including the obtained communication quality. The level adjustment reply signal is adjusted to the maximum transmission level by controlling the level adjustment unit 21rv by the level control 22rv, and transmitted from the PLC unit 14rv to the power line L toward the communication partner (the transmission source of the level adjustment signal). (Level adjustment reply signal transmission step).

  When receiving the level adjustment reply signal, the PLC unit 14 of the communication partner (source of the level adjustment signal) 1 obtains the communication quality of the received level adjustment reply signal. Based on the communication quality, the control unit 12 obtains a transmission output level for transmitting a PLC communication signal with a minimum communication quality that can be communicated with the transmission source PLC devices 1 and 2. The transmission output level is stored in the storage unit 11 in association with the IDs of the PLC devices 1 and 2 that are the transmission sources. By operating in this way, when the PLC device (master unit) 1 receives this command communication signal from the power line L by the PLC unit 14, the communication control unit 14 communicates with other PLC devices 1 and 2 adjacent in communication. The transmission output level of the PLC unit 14 can be controlled so as to transmit a PLC communication signal with a preset minimum communication quality that can be communicated.

  Such an operation is executed, for example, in parallel or sequentially between the adjacent nodes 1 and 2 searched as the adjacent nodes 1 and 2 of the own device 1 in the level adjustment signal transmission step.

  In the above description, based on the communication quality of the level adjustment signal or the communication quality of the level adjustment reply signal, the PLC communication signal can be communicated with the other PLC devices 1 and 2 adjacent to each other in communication. The transmission output level for transmitting the signal is obtained, but the level adjustment signal and the level adjustment reply signal are repeated one or more times while sequentially reducing the transmission output level at predetermined intervals. By transmitting and receiving, a transmission output level for transmitting a PLC communication signal with a minimum communication quality capable of communicating with other PLC apparatuses 1 and 2 adjacent in communication may be obtained.

  By operating in this way, in the PLC devices 1 and 2 and the PLC method in the present embodiment, when the own device is set as the parent device 1, the transmission output level is set to the other PLC devices 1 and 2. While the command communication signal to be adjusted is transmitted, when the command communication signal is received, the other PLC device (adjacent) adjacent on the communication regardless of whether the own device is the parent device 1 or the child device 2 The transmission output level of the PLC unit 14 is controlled so that the communication signal is transmitted with the minimum communication quality that allows communication with the nodes 1, 2. Thus, since the transmission output level of the PLC unit 14 is controlled to a level at which communication with the adjacent nodes 1 and 2 is possible, interference occurring between the PLC networks NT can be suppressed. Moreover, the transmission output level is not simply adjusted to prevent interference between the PLC networks NT, and communication quality in communication with the adjacent nodes 1 and 2 is ensured to a predetermined level and a minimum level at which communication is possible. Thus, the transmission output level is adjusted appropriately. Since the transmission output level of the PLC unit 14 is only controlled in this way, the frequency band used for the PLC is not limited.

  In addition, when performing media access using CSMA, interference between groups G can be prevented after such adjustment of the transmission output level. Therefore, it is necessary to allocate CSMA time for handset 2 belonging to another group G. There is no.

  In the above-described embodiment, in the command notification step, the other PLC devices 1 and 2 to which the command communication signal is transmitted by the command notification unit 122 are PLCs physically formed by the plurality of PLC devices 1 and 2. A device belonging to another group G different from the group G to which the own device 1 belongs in the case where a plurality of groups G that are classified according to logical communication availability are formed in the network NT. Good. For example, when the parent device 1-1 belonging to the group G-1 performs the above-described operation, the communication control unit 14 searches for the adjacent nodes 1 and 2 of the own device 1-1 in the level adjustment signal transmission step. Next, the PLC device 2-1 belonging to the group G-1 is excluded from the searched adjacent nodes 1 and 2, and the remaining PLC devices 1 and 2 belonging to the other groups G-2 and G-3 are leveled. The search result in the adjustment signal transmission step is used. Similarly, the group G includes a case where the group and the physical PLC network NT match. By configuring in this way, the base unit 1 is summarized only in the communication route for the slave unit 2 of the group G to which the own unit 1 belongs, and the storage capacity for storing the communication route in the storage unit 11 is reduced. Can do. For example, in the route table RTB of the base unit 1-1 before the transmission output level adjustment operation, as shown in FIG. 3A, for example, the group G of the group name “A” to which the base unit 1-1 belongs is assigned. -1 is registered, the communication route for the PLC devices 1-2 and 2-2 belonging to the group G-2 with the group name "B" and the group name "C" are registered. The communication routes for the PLC devices 1-3 and 2-3 belonging to the group G-3 in FIG. 3 are also registered, but in such a configuration, after the operation of adjusting the transmission output level, as shown in FIG. As described above, only the communication route for the slave unit 2 belonging to the group G-1 having the group name “A” to which the master unit 1-1 belongs is registered, and the PLC devices belonging to the other groups G-2 and G-3 are registered. 1-2, 1-3, 2-2, 2 Communication route for 3 is deleted. Also, since the transmission output level is adjusted in another group G different from the group G to which the own device 1 belongs, the PLC network NT is maintained while maintaining the communication state of the group G to which the own device 1 belongs. Interference occurring between them can be suppressed.

  In the above-described level adjustment signal transmission step, the other PLC devices 1 and 2 adjacent on the communication may be devices in which the parent device is set to the child device 2 by the parent-child setting unit 13. With this configuration, the transmission output level can be adjusted between the parent device 1 and the child device 2 in the group G to which the child device 2 to which the child device 2 belongs has been received. .

  Further, in the above, in the level adjustment signal transmission step, the other PLC devices 1 and 2 adjacent on the communication are connected in the PLC network NT composed of the plurality of PLC devices 1 and 2, respectively, When the communication route between the nodes is represented in a graph with a tree structure with the parent device 1 as the root, the child device 2 in the first layer, which is the next layer of the parent device 1, may be used. With this configuration, the above-described transmission output level adjustment is performed only between the parent device 1 and the first-layer child device (first terminal station) 2, so that the above-described entire PLC network NT is affected. It is possible to reduce the load accompanying the adjustment of the transmission output level. Here, the tree structure with the parent device 1 as the root of the communication route between the parent device 1 and the child device 2 includes the tree structure of only the root and the first layer. Even in such a case, the slave unit 2 on the downstream side of the second hierarchy or lower can communicate with the master unit 1 by being sequentially relayed by the slave unit 2 higher than the hierarchy of the own unit 2. . In particular, in the PLC network NT, there are many slave units 1 that are directly connected to the master unit 1 for communication. With this configuration, the PLC devices 1 and 2 are suitable for the PLC network NT. can do.

  Further, in the above-described embodiment, in the command notification step, the other PLC devices 1 and 2 to which the command communication signal is transmitted by the command notification unit 122 are set in the parent device 1 by the parent-child setting unit 13. It may be a device.

  FIG. 4 is a sequence diagram illustrating a transmission output level adjustment operation in the power line carrier communication network according to the embodiment. 5 and 6 show the route table (between parents) before and after adjusting the transmission output level, FIG. 5 shows the case of the base unit 1-1, and FIG. 6 shows the case of the base unit 1-2. FIGS. 5A and 6A show a route table between parents before transmission output level adjustment, and FIGS. 5B and 6B show parents after transmission output level adjustment. The route table between.

  More specific operation will be described for the case of the base unit 1-1. As shown in FIG. 4, first, in step S11, in the base unit 1-1, by referring to the route table RTB, The number of adjacent base units 1 adjacent to each other is confirmed, and a command communication signal (output suppression notification signal) is transmitted to each of the adjacent base units 1-2 and 1-3. In step S12, each of the parent devices 1-2 and 1-3 that have received the command communication signal adjusts the transmission output level to the parent device 1-1 by the above-described operation, and at the same time, the own devices 1-2 and 1 -3, the transmission output level adjustment operations are respectively performed by the above-described operations for the slave units 2-2 and 2-3 belonging to the groups G-2 and G-3, and the transmission output levels are respectively suppressed. A communication signal (suppression result notification signal) indicating that the operation of adjusting the transmission output level in the groups G-2 and G-3 of the own device 1-2 and 1-3 is completed at the suppressed transmission output level. -2, 1-3 are transmitted to the main unit 1-1. In step S13, when receiving each suppression result notification signal, base unit 1-1 obtains the communication quality of each received suppression result notification signal, and each of the obtained communication qualities is a predetermined value set in advance. It is determined whether or not it is equal to or less than a threshold value. As a result of this determination, if all the obtained communication qualities are equal to or less than a predetermined threshold value set in advance (YES), the base unit 1-1 ends this process, while the obtained communication qualities If any of the above is not less than or equal to the predetermined threshold (NO), base unit 1-1 returns the process to step S11.

  By operating in this way, the command communication signal is transmitted from the master unit 1-1 to the master units 1-2 and 1-3 belonging to the other groups G-2 and G-3. The transmission output level is adjusted with the parent devices 1-2 and 1-3 belonging to the other groups G-2 and G-3. As a result, in such a configuration, the communication routes of the other parent devices 1-2 and 1-3 are deleted, and the storage capacity for storing the communication routes can be reduced. For example, the route table RTB between the parents of the parent device 1 is only the communication route of the own device 1, and the storage capacity for storing the communication route in the storage unit 11 can be reduced. For example, in the route table TRB between parents in the parent device 1-1, communication routes of other parent devices 1 are registered as shown in FIG. 5A before the transmission output level is adjusted. After adjustment of the transmission output level, only the communication route of the own device 1-1 is obtained as shown in FIG. Similarly, for example, in the route table TRB between parents in the parent device 1-2, communication routes of other parent devices 1 are also registered as shown in FIG. 6A before the transmission output level is adjusted. However, after the transmission output level is adjusted, only the communication route of the own device 1-2 is obtained as shown in FIG.

  Further, by operating in this way, command communication signals are transmitted to the parent devices 1-2 and 1-3 belonging to the other groups G-2 and G-3, and the other groups G-2 and G-3 are transmitted. The above-described transmission output level adjustment can be performed by the parent devices 1-2 and 1-3 of the groups G-2 and G-3, and the load on the own device 1-1 can be reduced. .

  In the PLC network NT of the present embodiment, two transformers TrA are interposed between the two master units 1. The signal attenuation in the transformer TrA is generally relatively large, for example, about −20 dB to −30 dB, but interference may still occur between groups G. In the present embodiment, the transformer TrA is interposed between the parent devices 1, and interference generated between groups (including between PLC networks) via the transformer TrA can also be suppressed. The power line communication device disclosed in Patent Document 1 is a device used for a communication network in which each power line communication network group is constructed by using each power line (branch line) directly branched from one power line (trunk line) as a communication transmission path. Thus, interference that occurs via the trunk line is targeted for countermeasures, and interference via the above-described transformer TrA is not targeted for or suggested as in this embodiment.

In such a power line carrier communication apparatus in the present embodiment, the PLC communication unit 14 can be configured in a predetermined manner capable of realizing the above functions, but if a more specific example is shown, for example, The first to fourth aspects can be configured.
(First aspect of PLC communication unit 14)
FIG. 7 is a block diagram illustrating a configuration of the power line carrier communication device according to the first aspect of the embodiment.

  In the PLC communication unit 14A of the first aspect, as shown in FIG. 7, the level adjustment unit 21 includes an attenuator 21A that attenuates the input level and outputs it at a predetermined output level. With this configuration, the level adjustment unit 21 can be configured relatively easily.

  More specifically, as shown in FIG. 7, the PLC devices 1 and 2 transmit and receive communication signals by a PLC method with a storage unit 11, a control unit 12, and a parent-child setting unit 13 (not shown). And a PLC communication unit 14A. The storage unit 11, the control unit 12, and the parent-child setting unit 13 shown in FIG. 7 are the same as the storage unit 11, the control unit 12, and the parent-child setting unit 13 shown in FIG.

  The PLC communication unit 14A includes a coupling circuit 31, an attenuator (ATT) 21A, a level control circuit 22A, a transmission circuit 32, a reception circuit 33, and a power line carrier communication chip 34.

  The coupling circuit 31 is a circuit for connecting the PLC devices 1 and 2 and the power line so that they can communicate with each other. The coupling circuit 31 is connected to a pair of electric circuits in the power line and extracts a communication signal of the PLC that transmits the power lines (a pair of electric circuits). This is a circuit for superimposing a PLC communication signal on the power line. The coupling unit 13 includes, for example, a coupling capacitor having a sufficiently high impedance with respect to the commercial frequency of the commercial power source, and a primary winding connected in series with the coupling capacitor, so that the communication signal component of the PLC is connected to the primary side and 2 And a coupling transformer that can communicate with the next side. The PLC communication signal component is electrically connected between the input side and the output side of the coupling circuit 31 by the magnetic coupling of the coupling transformer, while the frequency component of the commercial power supply is connected to the input side and the output side of the coupling circuit 31. Is electrically insulated. In the case where electrical insulation is not required between the input side and the output side of the coupling circuit 31, an inductor may be used instead of the coupling transformer.

  The transmission circuit 32 is a circuit for amplifying a PLC communication signal (transmission signal) output from the power line carrier communication chip 34 to be transmitted to a predetermined signal level and outputting the signal to the coupling circuit 31. The transmission signal amplified by the amplifier is filtered so as to pass through an amplifier that amplifies the transmission signal of the signal to a predetermined signal level and the frequency band component of the PLC is transmitted, and is output to the secondary side of the coupling transformer A filter (a band pass filter or a high pass filter) is provided.

  The reception circuit 33 is a circuit for amplifying the PLC communication signal (reception signal) received and output by the coupling circuit 31 to a predetermined signal level and outputting the amplified signal to the power line carrier communication chip 34. For example, A filter (band-pass filter or high-pass filter) that is connected to the secondary side of the coupling transformer and filters the received signal so as to transmit the component in the PLC frequency band, and amplifies the output of the filter to power line carrier communication chip 34 And an amplifier that outputs to the output.

  The power line carrier communication chip 34 is connected to each of the transmission circuit 32 and the reception circuit 33, demodulates the reception data from the PLC communication signal (reception signal) taken out by the coupling circuit 31, and transmits the transmission data to the PLC communication signal. This is a circuit that modulates (transmission signal) and outputs it to the coupling circuit 31, and is, for example, an integrated circuit that is specialized for modulating / demodulating predetermined data in the PLC method.

  It should be noted that an attenuator 21A for attenuating the input level and outputting it at a predetermined output level is interposed between the transmission circuit 32 and the coupling circuit 31, and a level control for controlling the attenuator 21A. The circuit 22A is provided. The attenuator 21A is a variable attenuator that can change the attenuation rate, and includes, for example, a variable resistor. The attenuation rate of the attenuator 21A is controlled by the level control circuit 22A.

In the PLC communication unit 14A having such a configuration, the PLC communication signal transmitted through the power line is extracted by the coupling circuit 31, and the extracted communication signal (reception signal) is transmitted through the frequency band component of the PLC by the reception circuit 33. Then, the signal is filtered and amplified to a predetermined signal level and output to the power line carrier communication chip 34. Then, the power line carrier communication chip 34 demodulates the received signal to obtain received data. The acquired reception data is output to an external device connected to the power line carrier communication apparatuses 1 and 2. Also, transmission data input from the external device to the power line carrier communication chip 34 is modulated into a PLC transmission signal by the power line carrier communication chip 34, amplified to a predetermined signal level by the transmission circuit 32, and then transmitted to the PLC frequency band. Are filtered so as to pass through the components and output to the attenuator 21A. In the attenuator 21A, the attenuation factor is adjusted in accordance with the control of the level control circuit 22A, the transmission signal input from the transmission circuit 32 is attenuated to a predetermined signal level, and is output to the coupling circuit 31. As described above, the attenuator 21A, whose attenuation rate is adjusted according to the control of the level control circuit 22A, transmits a transmission signal with the minimum communication quality capable of communicating with other power line carrier communication apparatuses 1 and 2 adjacent on the communication. In this way, the output level of the transmission signal is adjusted. Then, the transmission signal adjusted to a predetermined output level by the attenuator 21A is superimposed on the commercial power source of the power line by the coupling circuit 31, and is transmitted through the power line.
(Second mode of PLC communication unit 14)
FIG. 8 is a block diagram illustrating a configuration of the power line carrier communication device according to the second aspect of the embodiment.

  In the PLC communication unit 14B of the second aspect, as shown in FIG. 8, the level adjustment unit 21 is a coupling circuit 31A that uses a transformer TrB capable of selecting a plurality of winding ratios and is communicably connected to a power line. . With this configuration, the level adjustment unit 21 can be incorporated into the coupling circuit 31A.

  More specifically, as shown in FIG. 8, the PLC devices 1 and 2 transmit and receive communication signals by a PLC method with a storage unit 11, a control unit 12, and a parent-child setting unit 13 (not shown). And a PLC communication unit 14B. The storage unit 11, the control unit 12, and the parent-child setting unit 13 shown in FIG. 8 are the same as the storage unit 11, the control unit 12, and the parent-child setting unit 13 shown in FIG.

  The PLC communication unit 14B includes a coupling circuit 31A, a level control circuit 22B, a transmission circuit 32, a reception circuit 33, and a power line carrier communication chip 34. The transmission circuit 32, the reception circuit 33, and the power line carrier communication chip 34 shown in FIG. 8 are the same as the transmission circuit 32, the reception circuit 33, and the power line carrier communication chip 34 shown in FIG.

  The coupling circuit 31A is a circuit for connecting the PLC devices 1 and 2 and the power line so that they can communicate with each other. The coupling circuit 31A is connected to the pair of electric lines L1 and L2 in the power line and transmits the power lines (the pair of electric lines L1 and L2). This is a circuit that extracts the communication signal and superimposes the PLC communication signal on the power line. The pair of electric lines L1 and L2 is the same as in the first aspect described above and the third and fourth aspects described later. For example, when performing PLC using a power line of 100V between lines as a transmission line, one is a neutral line. The other is a voltage line. For example, when PLC is performed using a power line of 200 V between lines as a transmission line, both are voltage lines (+100 V voltage line and −100 V voltage line). A higher voltage line such as 6 kV may be used.

  The coupling circuit 31A includes, for example, coupling capacitors C1 and C2 having sufficiently high impedance with respect to a commercial frequency of a commercial power source, and primary windings connected in series with the coupling capacitors C1 and C2 at both ends thereof, respectively. A coupling transformer TrB, TrC capable of mutually transmitting the communication signal component between the primary side and the secondary side, and a switch SWA for selecting a winding ratio of the coupling transformer TrB according to the control of the level control circuit 22B; It is configured with. The coupling transformer TrC is a coupling transformer for reception as long as it can transmit the communication signal component of the PLC from the primary side to the secondary side. Further, the coupling transformer TrB is a transmission coupling transformer as long as it can transmit the communication signal component of the PLC from the secondary side to the primary side. The PLC communication signal component is electrically connected between the input side and the output side of the coupling circuit 31A by the magnetic coupling of the coupling transformers TrB and TrC, while the frequency component of the commercial power source is the input side of the coupling circuit 31A. And the output side are electrically insulated.

  The transmission coupling transformer TrB is provided not only with terminals T1 and T5 at both ends of the secondary winding on the secondary side, but also with one or more lead wires drawn out from the middle of the secondary winding. The lead wire is also provided with a terminal (intermediate tap). In the example shown in FIG. 8, the coupling transformer TrB includes three intermediate taps T2, T3, and T4. One input terminal (ground terminal) in the transmission circuit 32 is connected to one terminal T5 of both ends of the secondary winding of the coupling transformer TrB. The other input terminal (signal terminal) in the transmission circuit 32 is selected by the switch SWA, as shown by a broken line, and the other terminal T1 and the intermediate taps T2 and T3 of both ends of the secondary winding of the coupling transformer TrB. , T4. Selection of the switch SWA is controlled by the level control circuit 22B. As a result, the winding ratio between the primary side and the secondary side of the transmission coupling transformer TrB is changed, and the transmission output level of the PLC transmission signal output from the secondary side to the primary side is changed. .

  The number of turns on the primary side is n1, the voltage on the primary side is v1, the number of turns on the secondary side is n2, the voltage on the secondary side is v2, and the winding ratio between the primary side and the secondary side is n Then, as is well known, generally, n = n2 / n1 = v2 / v1 holds. Here, as described above, since the winding ratio n can be changed by selecting the switch SWA, it is possible to transform between the secondary side and the primary side.

In the PLC communication unit 14B having such a configuration, a PLC communication signal transmitted through the power line is extracted by the coupling capacitors C1 and C2 of the coupling circuit 31A and the reception coupling transformer TrC, and the extracted communication signal (reception signal). Is filtered by the receiving circuit 33 so as to transmit the component in the frequency band of the PLC, amplified to a predetermined signal level, and output to the power line carrier communication chip 34. Then, the power line carrier communication chip 34 demodulates the received signal to obtain received data. The acquired reception data is output to an external device connected to the power line carrier communication apparatuses 1 and 2. The transmission data input from the external device to the power line carrier communication chip 34 is modulated into a PLC transmission signal by the power line carrier communication chip 34, amplified to a predetermined signal level by the transmission circuit 32, and the PLC frequency band. And is output to the secondary side of the receiving coupling transformer TrB in the coupling circuit 31A. In the coupling transformer TrB for reception, the winding ratio between the primary side and the secondary side is adjusted by the selective connection of the switch SWA according to the control of the level control circuit 22B, and input from the transmission circuit 32 to the secondary side. The transmitted signal is attenuated to a predetermined signal level and output to the primary side. The transmission coupling transformer TrB in which the winding ratio between the primary side and the secondary side is adjusted in accordance with the control of the level control circuit 22B in this way is connected to other power line carrier communication apparatuses 1 and 2 adjacent in communication. The output level of the transmission signal is adjusted so that the transmission signal is transmitted with the minimum communication quality that allows communication with the transmission signal. The transmission signal adjusted to a predetermined output level by the transmission coupling transformer TrB is superimposed on the commercial power source of the power line (a pair of electric paths L1 and L2) by the coupling capacitors C1 and C2, and is transmitted through the power line.
(Third and fourth aspects of PLC communication unit 14)
FIG. 9 is a block diagram illustrating a configuration of the power line carrier communication device according to the third aspect of the embodiment. FIG. 10 is a block diagram illustrating a configuration of the power line carrier communication device according to the fourth aspect of the embodiment.

  In the PLC communication units 14C and 14D of the third and fourth modes, as shown in FIGS. 9 and 10, the level adjusting unit 21 uses the operational amplifier OP that can select a plurality of feedback resistance ratios to be transmitted. This is the amplifiers Amp1 and Amp2 of the transmission circuit 32B that amplifies the signal and outputs it at a predetermined output level. With this configuration, the level adjustment unit 21 can be incorporated in the amplifiers Amp1 and Amp2 of the transmission circuit 32B.

  More specifically, in the third mode, the PLC devices 1 and 2 are, as shown in FIG. 9, a storage unit 11 (not shown), a control unit 12, a parent-child setting unit 13 (not shown), and a PLC system. And a PLC communication unit 14C that transmits and receives communication signals. In the fourth mode, as shown in FIG. 10, the PLC devices 1 and 2 transmit and receive communication signals by the PLC method with the storage unit 11 (not shown), the control unit 12, and the parent-child setting unit 13 (not shown). And a PLC communication unit 14D. The storage unit 11, the control unit 12, and the parent-child setting unit 13 shown in FIGS. 9 and 10 are the same as the storage unit 11, the control unit 12, and the parent-child setting unit 13 shown in FIG. To do.

  The PLC communication unit 14C of the third aspect includes a coupling circuit 31, a level control circuit 22C, a transmission circuit 32A, a reception circuit 33, and a power line carrier communication chip 34. The PLC communication unit 14D of the fourth aspect includes a coupling circuit 31, a level control circuit 22D, a transmission circuit 32B, a reception circuit 33, and a power line carrier communication chip 34. The coupling circuit 31, the receiving circuit 33, and the power line carrier communication chip 34 shown in FIG. 9 and FIG. 10 are the same as the coupling circuit 31, the receiving circuit 33, and the power line carrier communication chip 34 shown in FIG. To do.

  First, the transmission circuit 32A in the PLC communication unit 14C of the third aspect amplifies the communication signal (transmission signal) of the PLC to be transmitted, which is output from the power line carrier communication chip 34, to a predetermined signal level and sends it to the coupling circuit 31. For example, an amplifier AmpA that amplifies a PLC transmission signal to a predetermined signal level and a transmission signal amplified by the amplifier AmpA so as to transmit a component in the PLC frequency band are combined by filtering. An unillustrated filter (a band pass filter or a high pass filter) that outputs to the circuit 31 is provided.

  The amplifier AmpA is a switch that selects the feedback resistance ratio of the operational amplifier OP according to the control of the operational amplifier OP, the first resistor R11, the plurality of second resistors R21, R22, R23 having different resistance values, and the level control circuit 22C. And SWB. In the example illustrated in FIG. 9, the amplifier AmpA includes three second resistors R21, R22, and R23 having different resistance values. The output terminal of the power line carrier communication chip 34 is connected to the inverting input terminal (−) of the operational amplifier via the first resistor R11. The non-inverting input terminal (+) of the operational amplifier is grounded, and its output terminal is connected to the coupling circuit 31. A plurality of second resistors R21, R22, and R23 are connected in parallel to each other between the inverting input terminal (−) and the output terminal of these operational amplifiers via the switch SWB. By selecting and connecting the switch SWB, a resistor connected between the inverting input terminal (−) and the output terminal of the operational amplifier is selected from the plurality of second resistors R21, R22, and R23. The selection of the switch SWB is controlled by the level control circuit 22B. As a result, the feedback resistance ratio of the operational amplifier OP is changed, and the transmission output level of the PLC transmission signal to be output is changed.

  The amplifier AmpA using the operational amplifier OP having such a configuration is a so-called inverting amplifier circuit. The input voltage is vin, the output voltage is vout, the resistance value of the first resistor R11 is r1, and the resistance value of the second resistor R2n. Is r2 and the feedback resistance ratio is r (= r2 / r1), as is well known, vout = (r2 / r1) × vin = r × vin is generally established. Here, as described above, since the feedback resistance ratio r can be changed by selecting the switch SWB, the output voltage vout can be changed.

  Also, the transmission circuit 32B in the PLC communication unit 14D of the fourth aspect amplifies the PLC communication signal (transmission signal) to be transmitted, which is output from the power line carrier communication chip 34, to a predetermined signal level, and then to the coupling circuit 31. For example, an amplifier AmpB that amplifies a PLC transmission signal to a predetermined signal level and a transmission signal amplified by the amplifier AmpB so as to transmit a component in the PLC frequency band are combined by filtering. An unillustrated filter (a band pass filter or a high pass filter) that outputs to the circuit 31 is provided.

  The amplifier AmpB is a switch that selects a feedback resistance ratio of the operational amplifier OP according to the control of the operational amplifier OP, a plurality of third resistors R31, R32, and R33 having different resistance values, a fourth resistor R41, and the level control circuit 22D. And SWC. In the example illustrated in FIG. 10, the amplifier AmpB includes three third resistors R31, R32, and R33 having different resistance values. The non-inverting input terminal (+) of the operational amplifier is grounded, and its output terminal is connected to the coupling circuit 31. A fourth resistor R41 is connected between the inverting input terminal (−) and the output terminal of these operational amplifiers. A plurality of third resistors R31, R32, and R33 are connected in parallel with each other via the switch SWC between the output terminal of the power line carrier communication chip 34 and the inverting input terminal (−) of the operational amplifier OP. The A resistor connected between the inverting input terminal (−) of the operational amplifier OP and the output terminal of the power line carrier communication chip 34 among the plurality of third resistors R31, R32, R33 by the selective connection of the switch SWC. Selected. The selection of the switch SWC is controlled by the level control circuit 22D. As a result, the feedback resistance ratio of the operational amplifier OP is changed, and the transmission output level of the PLC transmission signal to be output is changed.

  The amplifier AmpB using the operational amplifier OP having such a configuration is a so-called inverting amplifier circuit. The input voltage is vin, the output voltage is vout, the resistance value of the third resistor R3n is r3, and the resistance value of the fourth resistor R41. Is r4 and the feedback resistance ratio is r (= r4 / r3), as is well known, generally, vout = (r4 / r3) × vin = r × vin, as in the amplifier amp1. Here, as described above, since the feedback resistance ratio r can be changed by selecting the switch SWC, the output voltage vout can be changed.

  In the PLC communication units 14C and 14D having such a configuration, the PLC communication signal transmitted through the power line is extracted by the coupling circuit 31, and the extracted communication signal (reception signal) is received by the reception circuit 33 in the frequency band component of the PLC. And is amplified to a predetermined signal level and output to the power line carrier communication chip 34. Then, the power line carrier communication chip 34 demodulates the received signal to obtain received data. The acquired reception data is output to an external device connected to the power line carrier communication apparatuses 1 and 2. The transmission data input from the external device to the power line carrier communication chip 34 is modulated into a PLC transmission signal by the power line carrier communication chip 34, amplified to a predetermined signal level by the transmission circuit 32, and the PLC frequency band. Is transmitted to the coupling circuit 31 and is superimposed on the commercial power source of the power line by the coupling circuit 31 to transmit the power line. Here, in the amplifiers AmpA and AmpB, the feedback resistance ratio r of the operational amplifier OP is adjusted by the selective connection of the switches SWB and SWC according to the control of the level control circuits 22C and 22D, and the transmission circuits 32A and 32B are transmitted from the power line carrier communication chip 34. Is amplified so as to have a predetermined signal level, and is output to the coupling circuit 31. As described above, the amplifiers AmpA and AmpB of the transmission circuits 32A and 32B in which the feedback resistance ratio r of the operational amplifier OP is adjusted according to the control of the level control circuits 22C and 22D are connected to other power line carrier communication apparatuses 1 and 2 adjacent in communication. The output level of the transmission signal is adjusted so that the transmission signal is transmitted with the minimum communication quality that allows communication. In the coupling circuit 31, the PLC transmission signal whose output level is adjusted is superimposed on the commercial power source of the power line, and is transmitted through the power line.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

AmpA, AmpB Amplifier C1, C2 Capacitor NT Power line carrier communication network OP Operational amplifier R11 First resistor R21, R22, R23 Second resistor R31, R32, R33 Third resistor R41 Fourth resistor SWA, SWB, SWC switch TrA Transformer TrB, TrC Coupling transformer 1, 2 Power line carrier communication device (PLC device)
11 Storage unit 12 Control unit 13 Parent-child setting unit 14, 14A, 14B, 14C, 14D Power line carrier communication unit (PLC unit)
21 level adjustment unit 22, 22A, 22B, 22C, 22D level control unit 31, 31A coupling circuit 32, 32A, 32B transmission circuit 33 reception circuit 34 power line carrier communication chip 111 route table storage unit 121 table processing unit 122 command notification unit 123 Relay processing unit 141 Communication control unit

Claims (12)

A communication unit that transmits and receives communication signals using the power line carrier communication method;
When the own device is a master station, a command notification unit that transmits a command communication signal for adjusting the transmission output level of the other power line carrier communication device from the communication unit, and
When the command communication signal is received by the communication unit, the transmission output level of the communication unit is set so that the communication signal is transmitted with the minimum communication quality that can be communicated with other power line carrier communication devices adjacent on the communication. And a communication control unit for controlling the power line carrier communication device. Other power line carrier communication devices to which the command communication signal is transmitted by the command notification unit are divided into a plurality of groups that are logically divided into power line carrier communication networks formed by a plurality of power line carrier communication devices depending on whether or not communication is logically possible. 2. The power line carrier communication apparatus according to claim 1, wherein the power line communication device belongs to another group different from the group to which the own device belongs. The power line carrier communication apparatus according to claim 2, wherein the other power line carrier communication apparatus adjacent on the communication is a slave station. Other power line carrier communication devices adjacent to each other on the communication are graphed in a power line carrier communication network composed of a plurality of power line carrier communication devices in a tree structure with the parent station as the root of the communication route between the master station and the slave station. The power line carrier communication apparatus according to claim 3, wherein when expressed, the power line carrier communication device is a slave station of the first hierarchy that is the next hierarchy of the master station. The power line carrier communication apparatus according to any one of claims 2 to 4, wherein the other power line carrier communication apparatus to which the command communication signal is transmitted by the command notification unit is a master station. The power line carrier communication apparatus according to claim 5, wherein a transformer is interposed between the own apparatus and another power line carrier communication apparatus to which the command communication signal is transmitted by the command notification unit. The communication control unit
A level adjuster for controlling the transmission output level of the communication signal;
A level control unit that controls the level adjustment unit so as to transmit the communication signal with a minimum communication quality capable of communicating with other power line carrier communication apparatuses adjacent in communication when the own device is a master station; The power line carrier communication device according to any one of claims 1 to 6, wherein the power line carrier communication device is provided. The power line carrier communication apparatus according to claim 7, wherein the level adjustment unit is an attenuator that attenuates an input level and outputs the signal at a predetermined output level. The power line carrier communication device according to claim 7, wherein the level adjustment unit is a coupling circuit that uses a transformer capable of selecting a plurality of winding ratios and is connected to be communicable with a power line. The said level adjustment part is an amplifier which amplifies the communication signal which should be transmitted using the operational amplifier which can select several feedback resistance ratio, and outputs it with a predetermined | prescribed output level. Power line carrier communication device. In a power line carrier communication method in a power line carrier communication network comprising a parent power line carrier communication device which is a parent station and one or more child power line carrier communication devices which are slave stations.
When the own machine is a master station, a command communication signal for adjusting the transmission output level of the other power line carrier communication device is transmitted from a communication unit that transmits and receives the communication signal in the power line carrier communication method; and
When the command communication signal is received by the communication unit, the transmission output level of the communication unit is set so that the communication signal is transmitted with the minimum communication quality that can be communicated with other power line carrier communication devices adjacent on the communication. And a communication control step for controlling the power line carrier communication method. In a power line carrier communication network comprising a parent power line carrier communication device that is a parent station and one or more child power line carrier communication devices that are slave stations,
The power line carrier communication network according to any one of claims 1 to 10, wherein the parent power line carrier communication device is the power line carrier communication device according to any one of claims 1 to 10.

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