JP2004088771A - Power line carrier system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a variety of problems which a conventional power line carrier system confronts. <P>SOLUTION: The power line carrier system is provided with a filter portion at a power supply branching device capable of removing from an outside power line. The filter portion transmits a power line carrier signal of a signal system for the outside power line and breaks the power line carrier signal of a different signal system from the signal system for the outside power line. <P>COPYRIGHT: (C)2004,JPO

Description

<< The present invention relates to power line carrier communication for performing communication using a power line.

Ｅ ECHONET is drawing attention as a standard for networks in Japan using power lines in homes for Japan. ECHONET is an acronym for Energy Conservation and Homecare Network, and its contents are hereinafter referred to as ECHONET Standard Ver. 1.01 (issued by the ECHONET Consortium).

First, FIG. 12 shows the ECHONET system architecture.

In ECHONET, a range handled by a maximum of one unit of ECHONET is referred to as a "domain" because electric equipment installed in the ECHONET is generally systemized within the same range of management of property or security. In other words, the range of resources to be managed (existing products, home appliances, sensors, controllers, remote controllers, etc.) existing in the range of the network defined by ECHONET is defined as a domain.

In ECHONET, a system that communicates between an electric device and a “controller that monitors, controls, and operates the electric device” or that communicates between the electric device and the electric device to operate in cooperation is referred to as a “system”. The scope of the system is within the same domain and does not span multiple domains. One or more systems exist in a domain. When connecting the system outside the domain, an ECHONET gateway is installed and the connection is made via this.

ＣＨECHONET makes use of various transmission media and protocols so that an optimal system can be constructed by utilizing the characteristics of various transmission media. FIG. 13 shows an ECHONET network configuration model of a main transmission medium.

That is, as shown in FIG. 13, connection with the outside of the domain is made via an ECHONET gateway (GW). In addition, an ECHONET router is installed between different protocols (different transmission media) in the domain and connected by this.

ネ ッ ト ワ ー ク Networks separated by ECHONET routers are called "subnets". Even with the same protocol, another subnet can be configured by inserting an ECHONET router. The network configuration of a domain is represented by a set of subnets. In other words, the domain is a range in which information in the house is transmitted in a network including the ECHONET router.

In the subnet, an identifier of the node (Node ID) is defined, and is used as an identifier of at least the ECHONET communication function uniquely identified in the subnet (this is referred to as an ECHONET node). For each subnet, a unique subnet identifier (Net @ ID) is defined. In ECHONET, an ECHONET address is defined as a pair of a subnet identifier and a node identifier, and is used as an ECHONET node identifier that is uniquely identified in a domain.

Next, FIG. 14 shows a general power line carrier communication waveform.

In general power line carrier communication via a home power line, such as communication conforming to ECHONET, a carrier signal waveform 2002 is superimposed on a commercial power supply waveform 2001, and data is transmitted using this carrier signal wave. The frequency of the commercial power wave is 50 Hz or 60 Hz, and the frequency of the carrier signal wave is 10 kHz to 500 kHz.

Thus, according to the power line carrier communication, the existing power line can be used, so that it is not necessary to extend a new cable between the electric devices in the house. However, the conventional power line carrier communication has the following problems.

First, the power lines in the house were not originally designed for data communication, and many electrical devices unrelated to power line carrier communication were connected, and the length of the power lines in the house was reduced from several tens of meters to several hundred meters. Therefore, the signal is extremely deteriorated. Due to such severe deterioration of the signal, the signal transmission speed is extremely low at a maximum of 9600 bps.

電 気 Also, since electric devices with low impedance are connected to the power line, signals are absorbed by those electric devices. For this reason, a large transmission power of 100 mW is required on the side of the electric device that performs the power line carrier wave communication.

Furthermore, when a large number of electric devices compatible with power line carrier communication (hereinafter referred to as “power line carrier communication compatible devices”) are connected to the power line, all signals flow into the power line in the home, resulting in insufficient communication capacity. is there.

In addition, even if the information does not want to be leaked to a specific electric device, all signals flow into the power line in the house, so that the information can be illegally acquired in the house.

た め In order to solve such a problem, for example, Patent Literature 1 proposes a power line carrier system described below.

That is, as shown in FIG. 15, the power tap 2101 receives power supply from the external power line 2110 and connects the electric devices 2107a, 2107b, and 2108c to be communicated. By providing the block filter 2105 inside the power tap 2101, the signal between the electric devices 2107 a, 2107 b, and 2107 c is completely cut off from the external power line. With this configuration, in the communication between the electric devices 2107a, 2107b, and 2107c, the above-described problem caused by the external power line in the house can be solved.
JP-A-7-231284 JP-A-2002-124894

However, the conventional power line carrier system has the following problems.

First, according to the conventional power line carrier system, the communication target is limited to electric devices connected to the same power tap. That is, there is a problem that communication cannot be performed at all with an electric device that is not connected to the same power tap. If a communication with a device not connected to the same power tap is enabled, a new power line corresponding to high-speed communication will be laid in the house, and the burden on the user will increase.

According to the conventional power line carrier system, a signal is sent to all electric devices connected to the same power strip. That is, since a signal is also sent to an electric device that is not the object of communication, there is a possibility that communication processing becomes heavy, and there is also a problem in information security.

Furthermore, according to the conventional power line carrier system, it is necessary to prepare a power tap with a block filter separately from the electric equipment to be communicated. That is, there is a problem in that the simplicity of the power line carrier communication in which only the power outlet is inserted is lost.

The present invention aims to solve various problems of the conventional power line carrier system.

The present invention provides a power line carrier system for performing power line carrier communication via a power line to achieve the above object. The power line carrier system includes an electric device capable of performing at least power line carrier communication by a signal system for an external power line in a house. The signal system for the external power line in the house is a general power line carrier signal system that also considers the case where communication is performed via a power line provided in a relatively old house, and is, for example, a system based on the ECHONET standard. . The electric device has a function of performing at least communication using such a general power line carrier signal. It may have a function of performing communication using a unique power line carrier signal in addition to a general power line carrier signal. The unique power line carrier signal includes a signal assuming a new power line corresponding to high-speed communication. In the power transfer system of the present invention, instead of newly laying a power line, a power supply branching device that branches the power supplied from the power line and supplies the power to connected electric devices is used. By using a device detachable from an external power line, such as a power supply branching device, a power line corresponding to high-speed communication can be secured at a minimum cost as needed. The apparatus further includes a signal selection unit that allows a power line carrier signal of a signal system for an external power line to pass therethrough and blocks a power line carrier signal of a signal system different from the signal system for the external power line. Since this signal selection unit is disposed between the side receiving and supplying the power from the external power line, the power line carrier communication using a general power line carrier signal is related to which power line the electric device is connected to. It is possible without. Further, in the communication between the electric devices connected to the power supply branching device, the total length of the communication path is also shortened, and communication with lower transmission power than before can be performed.

Furthermore, in this power line carrier system, the power supply branching device may include a path control unit. The route control unit transmits the power line carrier signal only to the transmission destination electric device.

信号 By making the signal system of the electric device connected to the power supply branching device different for each device, it is possible to increase the transmission speed, reduce the power consumption, and the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a power line carrier system 100 to which the present invention is applied.

The power line carrier system 100 is based on the premise that the system adopts ECHONET technology for power line carrier communication via a home power line, and includes a power supply branching device 101 described below, and electric devices 107a, 107b, and 107c. Consists of Since the ECHONET technology has been described in the section of the related art, a detailed description thereof will be omitted here.

The power supply branching device 101 includes a main power supply-side plug 102, a main power supply-side power line 103, sub-power supply-side outlets 104a, 104b, and 104c, a filter unit 105, and a power line 106 inside the power supply branching device. The main power plug 102 is detachably connected to an external power outlet 111 provided on the external power line 110.

Electrical equipment 107a, 107b, 107c is composed of power lines 108a, 108b, 108c and power plugs 109a, 109b, 109c. The power plugs 109a, 109b, 109c are detachably connected to the sub-power outlets 104a, 104b, 104c.

Hereinafter, the configuration of the power line carrier system 100 will be described in more detail.

The power supply branching device 101 branches the power supplied from the external power line 110 and supplies the power to the electric devices 107a, 107b, 107c through the sub-power outlets 104a, 104b, 104c. A general power line carrier signal is superimposed on the external power line 110, and a frequency band of 10 kHz to 450 kHz is used for the frequency band of the carrier. A blocking filter 112 is provided between the external power line 110 inside the house and a power line outside the house (not shown). The blocking filter 112 blocks a general power line carrier signal on the external power line 110.

Here, since the communication between the electric devices 107a, 107b, and 107c is closed in the same power supply branching device, the number of connected electric devices is small and the communication distance is short. Therefore, in the present invention, a power line carrier signal between the electric devices 107a, 107b, and 107c is separated from a general power line carrier signal.

That is, the electric devices 107a, 107b, and 107c not only have a function of performing communication using a general power line carrier signal via the external power line, but also have a function of performing communication on the external power line carrier only for communication between the electric devices 107a, 107b, and 107c. It also has a function of performing communication using a frequency band different from the frequency of 1.7 MHz to 30 MHz. In this embodiment, as shown in FIG. 2, the signal wave of the power line has a frequency component 201 of the commercial power supply 50/60 Hz, a frequency component 202 of the power line carrier signal of the external power line, and the electric component 107a, 107b, 107c. And a frequency component 203 of the power line carrier signal. In order to select signals of these frequency components, the power transfer system 100 includes a filter unit 105 in the power supply branching device 101 in addition to the blocking filter 112.

The filter unit 105 of the power supply branching device 101 includes a filter that blocks a frequency component of 1.0 M or more, such as a frequency characteristic 204 (that is, a filter that passes the frequency component 201 and the frequency component 202 and blocks the frequency component 203). ). With such a configuration, it is possible to realize a function of passing a general power line carrier signal used in an external power line and not leaking a power line carrier signal unique to the electric devices 107a, 107b, and 107c to the external power line.

As described above, according to the present invention, in the communication between the electric devices 2107a, 2107b, and 2107c, the above-described problem (for details, see the section of the prior art) caused by the external power line in the house can be solved. However, the communication target is not limited to the electric devices connected to the same power tap.

However, here, only the power line carrier signal unique to the electric devices 107a, 107b, and 107c uses a frequency band different from that of the external power line, but at the same time, the transmission power of the electric devices 107a, 107b, and 107c ( It is also possible to lower the signal power level).

That is, according to the related art, a factor that a signal is absorbed by many electric devices having a low impedance connected to an external power line, and a signal deterioration because the length of the external power line ranges from several tens meters to several hundred meters. Due to factors such as extremely high transmission power, a large transmission power of 100 mW was required. On the other hand, according to the present invention, in communication between the electric devices 107a, 107b, and 107, the number of electric devices connected to the power supply branching device is small and the length of the power line is short. Communication becomes possible.

The power supply branching device 101 may be provided with a switching unit such as a switch, so that the function of the power supply branching device 101 can be switched according to the state of the switch. With this configuration, for example, the switch is turned off when the power supply branching device 101 is used as a normal power tap, or the switch is turned off when no signal including a general power line carrier signal is to be supplied to the external power line. Function switching such as turning off is enabled.

Similarly, a switching means such as a switch may be provided in the electric devices 107a, 107b, and 107c so that the functions of the electric devices 107a, 107b, and 107c can be switched according to the state of the switches. In this way, for example, when the switch is OFF, transmission is always performed at the same frequency as general power line communication, communication is not performed, or switching to communication means other than power line communication is performed. Function can be switched.

Here, although the form of the power supply branching device 101 is not particularly specified, it is a device having a function of branching the power supply such as a power tap, a table tap, an OA tap, a tap with an extension cord, a built-in outlet, and a distribution board. If there is, it can be adopted as the power supply branching device 101. Of course, the device may not be divided into a plurality of power sources (for example, a device having only a relay function such as an extension cord) or may be integrated with an electric device such as a service outlet.

Although the power supply branching device 101 is used alone here, the present invention is not limited to this. That is, it is also possible to adopt a form in which the power supply branching devices 101 are connected in multiple stages, such as connecting another power supply branching device 101 to the power supply branching device 101.

Further, in communication between the electric devices, a frequency (1.7 MHz to 30 MHz) higher than the carrier frequency (10 kHz to 450 kHz) of the external power line is used, but the present invention is not limited to this. That is, in the communication between the electric devices, a frequency lower than the carrier frequency may be used as long as the frequency does not overlap with the carrier frequency of the external power line.

Furthermore, here, the signal system of the signal superimposed on the power line is not specified. That is, any signal system may be adopted as long as only a specific range of frequencies is used. Here, the signal method refers to all signal-related methods such as signal waveform, frequency, power level, modulation method, and signal destination control. The system defined by each layer from the physical layer to the transport layer in the OSI (Open System Interconnection) reference model corresponds to the signal system here. This signaling system may or may not conform to ECHONET. For example, ASK, FSK, PSK, QAM, OFDM, etc. can be adopted as a modulation method.

Furthermore, the direction of communication and the number of communication targets are not defined here. That is, the communication in the present invention may be one-way communication or two-way communication, and may be one-to-many communication or many-to-many communication.

{Furthermore, here, the filter unit attenuates the power level of the specific frequency to 0, but it is not always necessary to attenuate the power level to 0. That is, if the signal is attenuated to a level at which there is no effect even if the signal flows through the external power line, the same effect as described above can be obtained.

Furthermore, the means for realizing the filter unit is not particularly limited. For example, a circuit that can withstand the AC voltage in the house, such as a resonance circuit including a passive element such as a capacitor or a coil, and that can withstand the power consumption of the connected electric device is adopted as the filter unit. be able to. Of course, the filter unit can be configured not only with passive elements such as capacitors and coils, but also with digital circuits and the like.

Here, the filter unit is a low-pass filter that blocks a frequency component of 1.0 MHz or more, but it is a matter of course that the filter unit is not limited to the low-pass filter. Further, the frequency component to be cut off is not limited to 1.0 MHz, and the frequency component used for communication between the electric devices connected to the power supply branching device is cut off (or the frequency component not used for the external power line is cut off). Any frequency can be used.

Here, the method of setting the frequency components cut off by the filter unit is not described, but the setting method is not particularly limited. That is, the frequency component cut off by the filter unit may be fixed for each power supply branching device, may be freely set by the user, or may be dynamically set by the filter unit itself as described below. You may do so.

For example, upon detecting the frequency of the signal flowing from the main power supply, the filter unit determines whether the frequency thus detected matches the frequency of the signal flowing from the sub power supply. If these frequencies do not match, the signal flowing from the sub-power supply is cut off. Of course, the method of dynamically setting the frequency component to be cut off by the filter unit is not limited to this.

In addition, when high-speed communication is performed using a unique power line carrier signal, the effects of radiated noise from electric devices and the like become large, conversely, radiated noise from the power supply branching device 101 affects electric devices, and May cause signal interference. For this reason, it is preferable to shield the power lines (power cords) of the power supply branching device 101 and the electric equipment connected thereto with a shield. FIG. 3 shows an example of a two-core power line having a shield. In this example, a copper wire braided shield 302 and an aluminum foil shield 303 are arranged inside a jacket 301 of the outermost layer. Copper core wires 304 and 305 through which signals flow are surrounded by these shields with insulator 306 or 307 and filler 308 interposed therebetween. An aluminum foil shield 302 and a copper wire braided shield 303 shield high frequency and low frequency noise.
(Embodiment 2)
Hereinafter, the present embodiment will be described only with respect to differences from the first embodiment.

FIG. 4 is a schematic configuration diagram of the power line carrier system 400 according to the present embodiment. The power line carrier system 400 includes a power supply branching device 401 and electric devices 407a, 407b, and 407c.

The power supply branching device 401 includes, in addition to the configuration of the power supply branching device 101 described in the first embodiment, a signal separation coupling unit 412a, 412b, 412c on the sub power supply side, a signal separation coupling unit 413 on the main power supply side, and a power supply It comprises a power line 414 in the branching device, signal lines 415a, 415b, 415c, 416, a router unit 405, a signal conversion unit 418, and a signal line 417.

Hereinafter, the configuration of the power line carrier system 400 will be described in more detail.

(4) The power supply branching device 401 branches the power supplied from the external power line 410 and supplies the power to the electric devices 407a, 407b, and 407c through the sub power supply side outlet. A general power line carrier signal is superimposed on the external power line 410, and a frequency band of the carrier wave uses 10 kHz to 450 kHz.

Here, the signal superimposed on the power lines of the electric devices 407a, 407b, and 407c is taken into the router unit 405 through the signal separation and coupling units 412a, 412b, and 412c and the signal lines 415a, 415b, and 415c. Further, a signal superimposed on the external power line 410 is also taken into the router unit 405 through the signal separation / coupling unit 413 and the signal line 416. That is, no signal flows through the power line 414 in the power supply branching device.

(4) The router unit 405 decodes the signal and specifies the electric device specified as the transmission destination. If the specified electrical device is any of 407a, 407b, and 407c, the signal is passed through the signal line corresponding to the electrical device and the signal separating / coupling unit. On the other hand, if the specified electrical device is not one of 407 a, 407 b, and 407 c, the signal flows to the external power line 410 through the signal line 416 and the signal separation / coupling unit 413.

As described above, according to the present invention, the power line carrier signal between the electric devices connected to the power supply branching device can not only be made to not flow to the external power line but also to only the necessary electric devices. It becomes possible.

By the way, communication between the electric devices 407a, 407b, and 407c has a short communication distance and few connected electric devices, so that communication with low transmission power is possible and transmission speed can be increased. On the other hand, communication on the external power line 410 requires a long transmission distance and a large number of electric devices to be connected, so that a high transmission power is required and a transmission speed cannot be increased.

Therefore, as described below, it is effective to use different signaling methods for communication between the electric devices 407a, 407b, and 407c and communication on the external power line 401. Although the meaning of the signaling method is as described in the first embodiment, hereinafter, particularly, the carrier frequency and the power level are referred to as the signaling method. Of course, in the present embodiment, a configuration in which a signal is blocked by filter section 105 (see Embodiment 1) is not employed, so that the frequency of a signal superimposed on a power line is not limited to a specific range of frequencies. .

First, when the communication between the electric devices 407a, 407b, and 407c and the communication on the external power line 401 are completely incompatible, the signal conversion unit 418 converts the signal system in both directions. However, when the signal system between the electric devices 407a, 407b, and 407c is a system that is upwardly compatible with the signal system on the external power line 401, the signal on the external power line 401 is passed directly to the electric devices 407a, 407b, and 407c. You can, but not the other way around. Therefore, in this case, the signal system is converted in one direction (the direction from the external power line 401 to the electric devices 407a, 407b, and 407c).

For example, when the carrier frequency differs between the signal system between the electric devices 407a, 407b, and 407c and the signal system on the external power line 401, the signal conversion unit 418 changes the frequency of the power line carrier signal between the electric devices 407a, 407b, and 407c. The frequency is converted to the frequency of a general power line carrier signal. Further, when only the necessary power level differs between the communication between the electric devices 407a, 407b, and 407c and the communication on the external power line 410 (that is, the communication between the electric devices 407a, 407b, and 407c is performed by a general power line communication. When the power conversion is performed at a lower power level), the signal converter 418 amplifies the power level of the power line carrier signal between the electric devices 407a, 407b, and 407c to the power level of general power line carrier communication.

As described above, according to the present invention, the signal system of the electric device connected to the power supply branching device can be different from the signal system of the external power line, so that the transmission speed can be increased and the power consumption can be reduced. And so on.

Note that, here, the power supply branching device including both the router unit and the signal conversion unit is illustrated, but the present invention is not limited to this. That is, the power supply branching device may include only the router unit, or may include only the signal conversion unit. Of course, this signal conversion unit and the filter unit described in the first embodiment may be provided in the same power supply branching device.

FIG. 4 illustrates a power supply branching device that individually controls signals on the sub-power supply side by the signal separation / coupling units 412a, 412b, and 412c, but the present invention is not limited to this. That is, as shown in FIG. 5, the signal on the sub power supply side may be controlled by one signal separation / coupling unit 512. Even in this case, the same effect can be obtained in that the power line carrier signal between the power supply electric devices connected to the same power supply branching device does not flow out to the external power line.

Although FIGS. 4 and 5 illustrate a power supply branching device having a router unit for controlling a signal communication path, the provision of such a router unit complicates the configuration of the power supply branching device. There are issues. In order to solve this problem, a switch for controlling a signal communication path may be provided in the power supply branching device instead of the router section (this switch and the router section may be collectively referred to as a “path control section”). ").

For example, when only the electric device 407a and the electric device 407c perform communication and do not perform communication with the electric device 407b or the external power line at all, only the switches corresponding to the electric device 407a and the electric device 407c are turned ON, The switches corresponding to the device 407b and the external power line are turned off. With such a configuration, it is possible to control the signal communication path, similarly to the configuration including the router unit. Of course, a configuration in which a similar switch is provided in the electric device itself instead of the power supply branching device may be adopted.
(Embodiment 3)
Hereinafter, the present embodiment will be described only with respect to differences from the above-described first or second embodiment.

FIG. 6 is a schematic configuration diagram of a power line carrier system 600 according to the present embodiment. The power line carrier system 600 includes an electric device 601 and an electric device 607.

The electric device 601 includes a main power supply side plug 602, a main power supply side power line 603, a sub power supply side outlet 604, a sub power supply side power line 606, a signal separating and coupling unit 612, a communication unit 613, a power supply unit 614, And a signal line 615. The main power plug 602 is detachably connected to an external power outlet 611 provided on the external power line 610.

The electric device 607 includes a power line 608 and a power plug 609. The power plug 609 is detachably connected to the sub power outlet 604.

Hereinafter, the configuration of the power line carrier system 600 will be described in more detail.

The electric device 601 not only takes in the electric power supplied from the external power line 610 into the power supply unit 614, but also supplies the electric device 607 through the sub power supply side outlet 604.

Here, the signal separation / coupling unit 612 of the electric device 601 separates the signal output from the electric device 607 through the power line 608 from a general power line carrier signal, and sends the signal to the communication unit 613 through the signal line 615. At this time, since no signal between the electric devices flows out to the power line 603, communication between the electric devices can be performed regardless of the external power line.

As described above, according to the present invention, it is not necessary to prepare a power tap having a block filter or the like. That is, it is possible to solve the problem that the simplicity of the power line carrier communication, which merely indicates the power outlet, is lost.

Here, the communication from the electric device 607 to the electric device 601 has been described as an example, but the present invention is not limited to this. That is, communication from the electric device 601 to the electric device 607 can be realized by the same procedure.

(4) Here, the form of the sub-power outlet 604 is not specified. That is, as long as it is built in the electric device and has a function of branching or relaying the power supply, it can be adopted as the sub power supply side outlet 604. Needless to say, the service outlet is also a form of the sub power outlet 604.

Further, here, the case where the number of outlets on the auxiliary power supply side provided in the electric device 601 is one is illustrated, but the present invention is not limited to this. That is, the electric appliance 601 may have a plurality of outlets on the auxiliary power supply side.

Further, here, it is assumed that no signal flows on the external power line 610. However, as in Embodiments 1 and 2, communication on the sub power supply side can be performed while communication to the external power line 610 is maintained. That is, a configuration in which the power supply branching device according to Embodiments 1 and 2 is incorporated in electric device 601 may be employed. In this way, for example, general power line carrier communication is performed between the electric device 601 and the electric device directly connected to the external power line, and general power line carrier communication is performed between the electric device 601 and the electric device 601. It is also possible to realize a high transmission rate by using a carrier frequency that is not used in the transmission.

Of course, similarly to the first and second embodiments, a switch may be provided in the electric device, and the signal may be controlled by operating the switch. In this way, for example, only when a switch provided on the electric device 601 is ON, it is possible to send a signal to the main power supply.
(Embodiment 4)
Hereinafter, the present embodiment will be described only with respect to differences from any of Embodiments 1 to 3.

Here, the description will be made on the assumption that a power line carrier communication compatible device such as a set-top box (STB), a TV, a stereo, a modem, and a power meter is connected to a power line in the house.

First, focusing on the STB, information transmitted by the STB to various electric devices will be described.

For example, the STB decodes a broadcast wave such as a satellite broadcast (BS), transmits a video signal to a TV, and transmits an audio signal to a stereo. When a pay broadcast or the like is viewed, billing information for the broadcaster is transmitted to the modem. Further, information on the power consumed by the in-home electric device (power consumption information) is transmitted to the in-home power meter.

These pieces of information transmitted from the $ STB differ in the amount of information and the required transmission speed. There is no problem as long as a transmission rate sufficient to transmit such information to the power line is not a problem, but it is not in such a state. However, when the transmission rate is changed, it is necessary to change the carrier frequency to be used, the level of the transmission power, and the like, and it is necessary to appropriately set parameters related to the transmission signal.

Therefore, according to the present invention, as shown in FIG. 7, the STB is provided with a correspondence table describing the transmission speed corresponding to the destination electrical device or the transmission information, and further, the carrier frequency and the power level corresponding to the transmission speed. I made it. In this way, by referring to the correspondence table, the STB can transmit an appropriate signal to each electric device.

Here, although the STB and the TV are illustrated here, the present invention can be applied to any electric device that can communicate with another electric device through a power line.

Also, only the transmission rate and the carrier frequency or power level associated therewith are illustrated as parameters relating to the transmission signal, but the parameter relating to the transmission signal may be any information as long as it is information relating to the condition of the transmission signal. For example, a communication standard can be adopted as a parameter related to a transmission signal. In this case, the plurality of communication standards described in the same correspondence table need not be compatible.

Furthermore, here, only one type of parameter is prepared for each type of electric device, but the unit for preparing the parameter is not particularly limited. That is, a plurality of types of parameters may be prepared for each type of electric equipment, or different parameters may be prepared for the same electric equipment depending on conditions such as an installation location.

Further, here, the correspondence table is prepared in advance in the electric device, but the method of creating and managing the correspondence table is not particularly limited. That is, the contents of the correspondence table may be changed at any time, or the correspondence table may be dynamically created.

Further, if communication is performed using a general power line carrier signal, communication can be performed regardless of whether or not the electric device is connected to the power supply branching device. Therefore, for example, a server connected to the external power line may manage a table for associating electric devices with communication systems used by the electric devices. In this case, the transmission source electric device specifies the transmission destination electric device and makes an inquiry to the server, and the server returns a communication method corresponding to the inquiry. The transmission source electric device can determine a communication method to be used for the communication according to the response.
(Embodiment 5)
As described above, according to the fourth embodiment, an appropriate signal can be transmitted from the STB to each electric device by referring to the correspondence table. However, according to the fourth embodiment, an appropriate signal cannot be transmitted to an electric device not described in the correspondence table. Further, when the number of electric devices increases and the correspondence table becomes large, there is a problem that a correspondingly large amount of storage area must be secured. Further, when a configuration for dynamically updating the contents of the correspondence table is adopted, the table management method becomes a problem.

Hereinafter, the present embodiment will be described only with respect to differences from the above-described fourth embodiment.

When transmitting a video signal from the STB to the TV, for example, as shown in FIG. 8, the STB inquires the TV about the maximum transmission speed using a general power line carrier signal (S1). Each device such as an STB or a TV has data of a signal system used by itself, here, communication speed, and returns a value of the data in response to a received inquiry. In response to the inquiry, the STB determines the communication speed with the TV (S2). When it is determined that the maximum transmission speed of the TV is equal to or higher than the maximum transmission speed of the STB (for example, 4.7 Mbps), a video signal of 4.7 Mbps is transmitted from the STB to the TV (S3). .

On the other hand, if it is determined that the maximum transmission speed of the TV is, for example, 2.7 Mbps, the video signal cannot be transmitted from the STB to the TV as it is. Therefore, in this case, the transmission of the video signal is canceled or the video signal is down-converted to 2.7 Mbps and then transmitted.

However, when transmitting information that does not require real-time properties, such as power consumption information transmitted from the STB to the wattmeter, the down conversion as described above is unnecessary. In this case, the information may be transmitted as it is at the maximum transmission rate determined by the inquiry.

As described above, according to the present invention, since a method is employed in which negotiation is performed between the communicating electric devices and the communication speed is determined, appropriate communication can be performed without managing the correspondence table. A signal can be transmitted under conditions.

Here, the case has been described where the transmission speed is determined between the electric devices communicating with each other, but the present invention is not limited to this. That is, as long as the information is related to the condition of the transmission signal such as the carrier frequency, the power level, and the communication standard, the information can be negotiated between the communicating electric devices as described above.

If an inquiry is made using a general power line carrier signal, a response can be obtained regardless of whether or not the device is connected to the power supply branching device of the present invention.
(Embodiment 6)
As described above, according to the fifth embodiment, a method is employed in which negotiations are performed between the communicating electric devices to determine at what transmission speed the communication is performed. Signals can be transmitted under communication conditions. However, in the fifth embodiment, since the signal system is determined based only on the information of the electric device, communication cannot be performed correctly if the maximum transmission speed of the communication path is exceeded.

Hereinafter, only the points of the present embodiment that are different from the fifth embodiment will be described.

FIG. 9 shows a state in which a plurality of electric devices are connected to a power line in the house. Here, the electric device 901 is an STB, the electric device 902 is a TV, the electric device 903 is a stereo, the electric device 904 is a modem, and the electric device 905 is a power meter.

The electric device 901 and the electric device 902 are connected to the power supply branching device 906, and the electric device 903 and the power supply branching device 906 are connected to the power supply branching device 907. The power supply branching device 907 and other electric devices 903 to 905 are directly connected to a power line 908.

As already described in the first to fifth embodiments, the transmission speed of a signal passing through an external power line cannot be increased, but the transmission speed of a signal closed in a power supply branching device must be increased. Can be.

Here, paying attention to the communication path from the STB 901 shown in FIG. 9, it is preferable to transmit a signal to the TV 902 and the stereo 903 at a high transmission rate without passing through the external power line 908. On the other hand, it is sufficient that a signal can be transmitted at a low transmission rate to the modem 904 and the power meter 905 passing through the external power line 908.

れ ば If the communication path between the electric devices can be recognized as described above, the signal can be transmitted at an appropriate transmission speed. Hereinafter, an example of a method of recognizing a communication path between electric devices that communicate with each other will be described with reference to FIG.

The power line carrier system 1000 includes a power supply branching device 1001 and electric devices 1007a, 1007b, and 1007c. The power supply branching device 1001 includes a signal separation / coupling unit 1012, a communication unit 1013, an ID (unique ID) 1014 unique to the power supply branching device, and a signal line 1015 in addition to a configuration for branching power. I have.

Here, when the power supply branching device 1001 receives the inquiry about the unique ID from the electric devices 1007a, 1007b, and 1007c connected to the power supply branching device, the power supply branching device 1001 transmits the unique ID 1014 through the signal separating / coupling unit 1012, the signal line 1015, and the communication unit 1013. return it. In this way, the electric devices that have obtained the same unique ID are connected to the same power supply branching device.

(4) If it is determined that the STB and the TV are in a good communication state, such as being connected to the same power supply branching device, the STB sends a high-quality video signal to the TV. On the other hand, if it is determined that the STB and the TV are in a bad communication state such as being connected via an external power line, the STB sends a video signal with reduced image quality to the TV.

As described above, in the present invention, since the unique ID is embedded in the power supply branching device, communication according to the communication path between the electric devices can be performed.

Here, the configuration in which the connection between the electric devices can be recognized by providing the power supply branching device with the unique ID is illustrated, but this configuration is merely an example for recognizing the connection between the electric devices, Another configuration may be adopted.

For example, a unique ID may be set for the power line itself instead of the power supply branching device, and the ID set in this manner may be outside the concept of the unique ID. That is, according to the configuration in which a unique group ID or the like is adopted for each predetermined group instead of the unique ID, it is not possible to specify individual communication paths, but it is difficult to determine whether the communication paths belong to the same group. That can be specified.

Also, when acquiring a unique ID using a general power line carrier signal, the unique ID can be acquired from a device directly connected to an external power line. Therefore, for example, the server connected to the external power line may manage a table that associates the ID of the electric device with the unique ID of the power supply branching device to which the electric device is connected. In this case, the transmission source electric device specifies the transmission destination electric device and makes an inquiry to the server, and the server returns a corresponding unique ID to the inquiry. The transmission source electric device can determine whether the transmission destination electric device is connected to the same power supply branching device according to the response.
(Embodiment 7)
As described above, according to the sixth embodiment, since the unique ID is embedded in the power supply branching device, communication according to the communication path between the electric devices becomes possible. However, in the sixth embodiment, the transmission speed is determined based only on the information as to whether or not they are connected to the same power supply branching device, so that correct communication may not be performed.

In other words, even when connected to the same power supply branching device, the maximum transmission speed depends on whether or not low impedance electrical equipment is connected to the power supply branching device, as well as factors such as the number of branches, power line length, and noise immunity. fluctuate. Further, even when the communication path passes through an external power line, the maximum transmission speed varies depending on whether the communication distance is a short distance or a long distance. Further, when a method of setting a unique ID to the power supply branching device is employed, there is a problem that the configuration of the power supply branching device becomes complicated.

Hereinafter, only the points of the present embodiment that are different from the sixth embodiment will be described.

When transmitting a video signal from the STB to the TV, if the transmission speed of the video signal is, for example, 4.7 Mbps, first, a test signal of 4.7 Mbps is sent from the STB to the TV. The TV receiving this test signal measures the error rate and the power level of the signal, and when the measured power level is attenuated from a specific value, cancels the signal transmission under the communication condition. Then, it requests the STB to increase the power level and retransmit the test signal.

(4) If the error rate is higher than a specific value even if the measured power level is not attenuated below a specific value, the signal transmission under the communication condition is canceled. Then, it requests the STB to lower the transmission rate and retransmit the test signal.

As described above, while changing the communication conditions of the test signal between the transmission electric device and the reception electric device, the communication conditions are adjusted so that the error rate and the power level satisfy the specified conditions. By doing so, the STB can transmit the video signal after performing processing such as down-conversion of the video signal according to the adjusted communication conditions.

As described above, according to the present invention, since the communication condition is determined by transmitting the test signal in advance, the communication condition that can be actually transmitted can be accurately obtained.

Note that, here, only the error rate and the power level are taken as the measurement items of the test signal, but other parameters may be measured.

Also, here, only changing the power level of the transmission signal based on the measurement result of the test signal is described, but the present invention is not limited to this. That is, instead of this power level, other information on the condition of the transmission signal, such as the carrier frequency and the communication standard, may be changed.
(Embodiment 8)
In order to prevent the power level from attenuating in communication between the electric devices connected to the power supply branching device, a device may be provided in the power supply branching device itself. Hereinafter, the present embodiment will be described only with respect to differences from the above-described seventh embodiment.

As shown in FIG. 11, the power supply branching device 1103 has a configuration in which an impedance upper portion 1104 is inserted between the external power line 1105 and the electric device 1101 and between the external power line 1105 and the electric device 1102. . The impedance upper section 1104 has a function of increasing the impedance when the external power line 1105 is viewed from the electric device 1101 or 1102.

For example, when a signal is transmitted from the electric device 1101 to the electric device 1102, the signal transmitted from the electric device 1101 reaches the electric device 1102 by the impedance upper portion 1104 without leaking the signal to the external power line 1105. By doing so, it is possible to determine whether or not the electric device 1101 and the electric device 1102 are directly connected by the power supply branching device 1103 by referring to the degree of attenuation of the power level of the test signal. The communication conditions can be changed according to the result.

Here, the method of realizing the impedance upper section is not particularly defined. That is, any realizing method may be adopted as long as the impedance on the side of the external power line 1105 viewed from the electric device 1101 or the electric device 1102 becomes high, such as a resonance circuit including a passive element such as a capacitor or a coil.

However, in the present embodiment, there is a problem that the configuration of the electric device becomes complicated because the electric device automatically determines the transmission speed. In order to solve this problem, a switch may be provided in the electric device, and a configuration in which the transmission speed can be changed depending on the state of the switch may be adopted.

For example, when the electric device 1101 and the electric device 1102 communicate with each other, if both devices are connected to the same power supply branching device, the switches attached to both devices are set to the high-speed mode, and the communication is performed at a high transmission speed. On the other hand, when both are connected via the external power line, the switches attached to both are set to the low-speed mode, and communication is performed at a low transmission speed. According to the configuration in which the switch is provided in the electric device, the transmission speed can be easily switched from the outside.

In each of the above-described embodiments, a system conforming to the ECHONET standard is adopted as a signal system used for low-speed transmission, and high-speed communication between electric devices is performed using a unique system using a frequency band of 1.7 MHz to 30 MHz. Was. However, the signaling method used in the system of the present invention is not limited to this example. As the signal system, various systems from all over the world, such as a system conforming to the LonWorks standard, the HomePlug standard, and the HomePlug AV standard currently being formulated, can be adopted. In LonWorks, FSK can be used as a modulation method, and its band is set at 125 kHz to 140 kHz. The signal transmission speed is 5400 bps at the maximum. In HomePlug, OFDM is used as a modulation method, and its band is set to 4 MHz to 21 MHz. Its maximum transmission speed is 14 Mbps, which is considerably higher than ECHONET or LonWorks. HomePlug @ AV is expected to have a much higher transmission speed in order to support distribution of moving image data such as HDTV.

For example, even when the external power line laid in the house cannot support a high-speed HomePlug signal and the only option is to use a lower-speed standard signal such as LonWorks for the external power line, the power line carrier of the present invention can be used. In the system, it is not necessary to re-install an external power line in order to cause communication between devices that support HomePlug. By connecting those devices to a power supply branching device that supports HomePlug, high-speed communication can be performed between the devices connected to the power supply branching device. If both the existing equipment connected to the external power line and the HomePlug-compatible equipment support a common signal system, low-speed communication with the power supply branching device and the external power line can be performed. it can. Furthermore, even if the existing external power line currently corresponds to a high-speed signal such as HomePlug, it is not possible to exclude the possibility that a higher-speed signal to be determined in the future such as HomePlug AV cannot be supported. Even in such a case, in the power supply branching system of the present invention, high-speed communication can be performed between the devices simply by connecting a device compliant with the standard to a power supply branching device compliant with the newly established standard. Since a HomePlug @ AV compatible device also supports HomePlug, a HomePlug signal is provided between a HomePlug @ AV compatible device connected to a power branching device and a HomePlug compatible device not connected to the power branching device. Can also be used for communication.

The power line carrier system according to the present invention can secure a power line corresponding to high-speed communication at a minimum cost as necessary by using a device that can be detached from an external power line, such as a power supply branching device. The present invention has an effect and is useful in power line carrier communication for performing communication using a power line.

FIG. 2 illustrates a power line carrier system according to Embodiment 1. 4 is a diagram illustrating frequency components of a power line carrier signal according to Embodiment 1. FIG. The figure which shows the cross section of an example of a power line FIG. 4 illustrates a power line carrier system according to Embodiment 2. FIG. 4 illustrates a power line carrier system according to Embodiment 2. FIG. 7 illustrates a power line carrier system according to Embodiment 3. FIG. 14 is a diagram for explaining a correspondence table according to the fourth embodiment. Flowchart for explaining power line carrier communication method FIG. 14 illustrates an example of power line connection of an electric device in Embodiment 6. FIG. 10 illustrates a power line carrier system according to Embodiment 6. FIG. 10 illustrates a power line carrier system according to Embodiment 8. Diagram showing the system architecture of ECHONET Diagram showing the network configuration of ECHONET Diagram explaining general power line carrier signal waveform Diagram for explaining a conventional power line carrier system

Explanation of reference numerals

100, 400, 500, 600, 1000, 1100, 2100 Power line carrier system 101, 401, 501, 906, 907, 1001, 1103, 2101 Power supply branch device 102, 602 Main power supply side plug 103, 603 Main power supply side power line 104, 604 Sub power outlet 105 Filter section 106,414 Power line in power supply branching device 107,407,507,601,607,901,902,903,904,905,1007,1101,1102,2107 Electrical equipment 108,608 Power lines 109, 609 Power plugs for electrical equipment 110, 410, 510, 610, 908, 1010, 1105, 2110 External power lines 111, 611 External power outlets 201 50/60 Hz signal component 202 10 kHz to 450 Hz signal component 203 1.7 MHz to 30 MHz signal component 204 Frequency characteristics of filter unit 302, 303 Shield 304, 305 Core wire 405, 505 Router unit 412, 512 Sub-power source side signal separation / coupling unit 413, 513 Main power side signal separation Coupling unit 415, 416, 417, 515, 516, 517, 1015 Signal line 418, 518 Signal conversion unit 606 Power line in electrical equipment 612, 1012 Signal separation coupling unit 613, 1013 Communication unit 614 Power supply unit 1014 Unique ID
1104 Impedance upper part 2001 Commercial power supply waveform 2002 Carrier signal waveform 2105 Block filter part

Claims (19)

In a power line carrier system for performing power line carrier communication via a power line,
Electrical equipment capable of performing at least power line carrier communication with a signal system for external power lines in the house,
Pass the power line carrier signal of the above-mentioned signal system, between the side receiving the power from the external power line and the side supplying the signal selecting unit for cutting off the power line carrier signal of the signal system different from the signal system for the external power line. And a device detachable from the external power line. The power line carrier system according to claim 1, wherein the device is a power supply branching device that branches power supplied from the external power line and supplies the power to a connected electric device. The power line carrier system according to claim 2, wherein the signal selector blocks a frequency component different from a power line carrier signal of the external power line signaling method. The power line carrier system according to claim 2, wherein the power supply branching device includes a path control unit that transmits the power line carrier signal only to the destination electrical device. The power line carrier system according to claim 2, wherein the power supply branching device includes a signal conversion unit that converts a signal system of the power line carrier signal into a specific signal system. The power line carrier system according to claim 5, wherein the signal converter converts a frequency of the power line carrier signal of a signal system different from the signal system for the external power line into a frequency of the power line carrier signal of the signal system for the external power line. . The power line according to claim 5, wherein the signal conversion unit converts a power level of a power line carrier signal of a signal system different from the signal system for the external power line into a power level of a power line carrier signal of a signal system for the external power line. Transport system. The power line carrier system according to claim 1, wherein the signal system for the external power line conforms to the ECHONET standard. The power line carrier system according to claim 1, wherein a filter for blocking the power line carrier signal of the external power line signal system is provided between the inside of the house and the outside of the house. The power line carrier system according to claim 1, wherein the electric device includes a shielded power cord. In electrical equipment that can perform power line carrier communication with a signal system for external power lines in the house,
An electric device that changes the signal system for the external power line to a different signal system depending on the electric device to which the signal is transmitted. The electric device according to claim 11, wherein an inquiry is made to an electric device to which a signal is to be transmitted using the signal method for the external power line, and the change is performed according to a result of the inquiry. The electric device according to claim 11, wherein the signal system is changed according to a communication path to the electric device to which the signal is transmitted. The electric device according to claim 11, wherein the change is performed depending on whether or not the electric device to which the signal is transmitted is connected to the same power supply branching device as the electric device. The electric device according to claim 11, wherein before transmitting the signal, a test signal is transmitted to the electric device to which the signal is transmitted, and the change is performed according to a test result. The electric device according to claim 15, wherein the change is performed according to an error rate of a test signal. The electric device according to claim 15, wherein the change is performed according to a degree of attenuation of the test signal. In a power supply branching device that branches power supplied from an external power line in the house and supplies the power to connected electric devices,
Pass the power line carrier signal of the external power line signal system, between the external power line side and the electric device side a signal selection unit that cuts off the power line carrier signal of a signal system different from the signal system for the external power line Power supply branching device equipped. A method for performing power line carrier communication via a power line between electrical devices connected to the power line,
A procedure for determining whether to use a signaling method for the external power line in the house or to use a signaling method different from the signaling method for the external power line according to the communication destination electrical device,
Performing a power line carrier communication with the electric device according to the determined signaling method.

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