JPS6214146B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power line carrier control system, more specifically, a power line carrier that connects a transmitter and a receiver via a power line and controls a load connected to the receiver using a control signal from the transmitter. Regarding control method.

Generally, this type of power line carrier control system connects at least one transmitter T and a plurality of receivers R via a power line L, as shown in FIG. The load connected to the receiver R is controlled by the transmission signal Tr transmitted to the receiver R. As shown in Fig. 2, the transmission signal Tr transmitted from the transmitter T to the receiver R includes a start signal St for specifying the beginning of the transmission signal Tr and putting the receiver R into the receiving state, and a unique channel for each transmission signal Tr. The channel signal Ch for accessing each receiver R individually and the control signal Cn for performing load control such as on/off control are arranged in chronological order, and the response section is next to the transmission signal Tr. When the installed receiver R operates reliably, the transmitter T
The return signal Rt sent back to the transmitter T
When the transmitter T receives the signal, one access from the transmitter T to the receiver R is completed. In this way, each receiver R is accessed individually. By the way, if you want to control the loads all at once, such as when you want to turn on all the loads of the receivers R connected to the power line L, and there are 16 channels that can be accessed by the transmitter T. As shown in Fig. 3, if there are only 6 receivers R actually connected to the power line L, each having 1, 2, 5, 10, 15, and 16 channels. However, in the conventional system, it was necessary to access all 16 channels in sequence when controlling loads simultaneously. In other words, in this control method, each time each receiver R is accessed, the return signal Rt is received and the operating status of each receiver R is checked, so even during simultaneous control, each channel is They had to be accessed in sequence. Therefore,
In this case, if the time required to access one channel is t, then regardless of the number of receivers R, the time required for simultaneous control will be t multiplied by the number of channels, that is, if the number of channels is 16, it will take 16t. In particular, it had the disadvantage of slow control.

Furthermore, when the distance from the transmitter T to the receiver R is long, the transmission signal Tr may be attenuated and not reach the receiver R due to the resistance of the power line L or the state of the load connected to the power line L. Therefore, in such a case, the transmitter T is divided into a parent transmitter P and a relay transmitter I as shown in Fig. 4, and the relay transmitter I is placed within the signal transmission range from the parent transmitter P. The transmitter P performs operations for load control, and the relay transmitter I amplifies the transmission signal Tr from the parent transmitter P and transmits it to the receiver R, and the return signal Rt from the receiver R is amplified by the relay transmitter I. The signal was sent back to the parent transmitter P via the relay transmitter I. In this case, in order to access the receiver R corresponding to one channel, as shown in FIG. From transmitter I to parent transmitter P
It is necessary to transmit the signal to the receiver R
The time required to access the relay transmitter I was approximately three times the time required when the relay transmitter I was not provided, resulting in a delay in signal transmission. That is, the above transmission signal Tr is transmitted from the parent transmitter P to the relay transmitter I, and a reply section is also provided, but at this time, the transmission signal Tr has not reached the receiver R, so the return signal is not transmitted.
Rt is not returned, and the transmission signal is then transmitted from the parent transmitter P from the relay transmitter I to the receiver R.
A transmission signal Tr identical to Tr is transmitted, and at this time, a return signal Rt from the receiver R is transmitted to the relay transmitter I. The relay transmitter I then accesses the parent transmitter P again using the same transmission signal Tr, and when it receives the return signal Rt from the parent transmitter P, it confirms the signal transmission and completes one control for one channel. It is. As a result, when performing simultaneous control as shown in the example above, all channels are accessed in order, and the control time per channel is three times longer than usual, so When the number of R is small, signal transmission takes an unnecessarily long time, resulting in a delay in control.

The present invention has been made in view of the above-mentioned problems, and its main purpose is to perform operations by accessing only the channel of the receiver actually connected to the power line during load control. Another purpose is to shorten the control time from when the load is controlled until the load is controlled.Another purpose is to shorten the control time by transmitting a control signal according to the load control state of the receiver connected to the power line. In addition to shortening the time, the objective is to perform reliable control.

Hereinafter, specific embodiments of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, the power line carrier control system of the present invention is configured by connecting at least one transmitter T having an operation section via a power line L and a plurality of receivers R to which loads are connected. . In this embodiment, the transmission signal Tr transmitted from the transmitter T to the receiver R is the sixth
As shown in the figure, a 1-bit start signal St, a 4-bit channel signal Ch, and a 4-bit control signal
Cn are consecutively arranged in order, and a reply section is provided after the transmission signal Tr to receive the 4-bit return signal Rt sent back from the receiver R, and the transmission signal Tr is transmitted from the transmitter T to the receiver. The return signal Rt is sent back from the receiver R to the transmitter T.
Terminate access for one channel. In this embodiment, the control signal Cn includes an individual ON signal S _E , an individual OFF signal S _F , a simultaneous ON signal S _A , and a simultaneous OFF signal S _B , and the individual ON signal _SE and the individual OFF signal S _F are transmitted to each receiver. The loads of receivers R are controlled on and off individually, and the simultaneous on signal S _A and the simultaneous off signal S _B are used to simultaneously control on and off the loads of all receivers R connected to the power line L. In addition, like the control signal Cn, the status confirmation signal S _I , which has a reply section before and after which the start signal St, channel signal Ch, and return signal Rt are returned, is used when none of the above four signals are transmitted. It is output periodically at intervals of about 3 to 5 minutes, and the receiver R that receives the status confirmation signal S _I returns whether the load is on or off without performing on/off control of the load. signal
Reply to transmitter T as Rt. These control signal Cn and status confirmation signal S _I are composed of a predetermined code as shown in FIG. 6, for example. By the way, the transmission signal Tr and the return signal Rt are synchronized with the commercial power supply AC, and for example, as shown in Fig. 7, one bit of data is constructed in a half cycle of the commercial power supply AC, and this half cycle is divided into four. The high frequency signal that becomes the carrier wave is interrupted for each section, and by the combination of interruptions, the start signal St and 0 equal to 1 bit are generated.
and 1 signal. In the example in Figure 7, the presence or absence of a carrier wave is represented by 0 and 1, and 0101 is the start signal.
St, 0111 is 1 and 0100 is 0. In Figure 6, the channel signal Ch is 4 bits, so
In this embodiment, a maximum of 16 receivers R having different channels can be connected, but the receivers R actually connected are 1, 2, 5, 10, 15, and 15 as shown in FIG. Assume 6 receivers R with 16 channels each. As described above, the transmitter T periodically sends out the status confirmation signal S _I , sequentially accesses all channels that can be connected to the transmitter T, that is, 16 channels in this embodiment, and connects to the power line L. The receiver R sends back to the transmitter T whether the load of the receiver R is on or off as a return signal Rt. Of course, if the receiver R having the accessed channel is not connected to the power line L, the return signal Rt will not be returned. Therefore, as shown in Figure 8a,
The status confirmation signal S _I sent from the transmitter T distinguishes between channels in which the return signal Rt is returned and channels in which it is not returned. In this way, the channels actually in use are determined, and during simultaneous control, only these used channels are accessed as shown in FIG. 8b, thereby shortening the control time.

Next, block diagrams of a transmitter T and a receiver R for performing the above operations are shown in FIGS. 9 and 10, respectively. Shown in FIG. 9 is a block diagram of the transmitter T. 1 is a zero cross detection section,
A synchronizing pulse synchronized with the zero cross of the commercial power supply AC is output, and a clock generator 2 generates a clock pulse for controlling the timing within the transmitter T based on this synchronizing pulse. Reference numeral 3 denotes a key input memory section which stores setting inputs for the channel designation switch and the individual on/off switch of the individual operation section 4, which are operated when controlling each receiver R individually. Reference numeral 5 denotes a confirmation signal timer section for generating a status confirmation signal S _I at predetermined time intervals. In addition, 6 has a simultaneous on/off switch,
This is a simultaneous operation unit for performing simultaneous control. The above key input memory section 3, confirmation signal timer section 5
The output of the simultaneous operation section 6 is input to the signal discrimination section 7, which determines whether the control signal Cn is the status confirmation signal S _I , the individual on/off signals _SE , _SF , or the simultaneous on/off signals S _A , S _B. The output is divided into two parts and inputted to the transmission channel determination unit 8 and control data creation unit 9, respectively, in order to determine the priority order of transmission and to create a channel signal Ch and a control signal Cn corresponding to each signal. In the transmission channel determining section 8, when the control signal Cn is the individual on/off signal _SE , _SF , the output of the signal determining section 7 is sent as is to the channel data creating section 10, and when the control signal Cn is the simultaneous on/off signal S _A , _SB , it is sent to the response channel. The channel data of the channels actually used stored in the memory part 16 are outputted, and further, when the status confirmation signal S _I is the control signal Cn, the channel data of all the channels are sequentially transmitted to the channel data creation part 10. In this way, the channel data created by the channel data creation section 10 and the control data created by the control data creation section 9 are temporarily stored in the transmission data memory section 11, and a start signal St is added to them to send out the transmission signal Tr. transmission data is formed. Then, when transmission starts, the transmission data in the transmission data memory section 11 is sequentially read out, and the encoder 1
2 performs code conversion to represent 1 bit as a 4-bit code. That is, as described above, 1 is converted to 0111, the start signal St is converted to 0101, etc. The output of the encoder 12 is sent to the modulator/demodulator 1
3, the carrier wave is amplitude-modulated according to the code to form a transmission signal Tr, and this transmission signal
The Tr is sent to the power line L. The modulation/demodulation unit 13 can also receive the return signal Rt from the receiver R, and the return signal Rt is demodulated by the modulation/demodulation unit 13 and becomes 4.
The signal is sent as a bit signal to the decoding section 14, where the 4-bit signal is converted into 1-bit reply data corresponding to the signal. The reply data obtained in this way is judged by the reply data determining section 15 as to whether there is a reply or not and the control state of the load on/off of the receiver R, and the channel in which there was a reply to the status confirmation signal S _I is stored in the reply channel memory. 16, and the load control state is displayed on the display section 17. FIG. 10 is a block diagram of receiver R. Like the transmitter, the receiver R also has a zero cross detection section 18, a clock generation section 19, a modulation/demodulation section 20, a decoding section 21, and an encoding section 22, and these functions are the same as those in the transmitter T. That is, the clock generator 19 outputs a clock pulse for timing the receiver R based on a signal synchronized with the zero cross of the commercial power supply AC obtained by the zero cross detector 18.
Since the receiver R is connected to the same power line L as the transmitter T, the transmitter T and receiver R can be synchronized by synchronizing with the commercial power supply AC. By the way, the transmission signal Tr transmitted from the transmitter T to the receiver R via the power line L as described above is demodulated by the modulation/demodulation section 20 of the receiver R, and is output as the output of the decoding section 21 using the same procedure as described above. Received data can be obtained. This received data is temporarily stored in a received data memory section 23 whose memory is cleared by the start signal St, and is divided into channel data and control data.
The signals are input to a channel data determining section 24 and a control data determining section 25, respectively. The output of the channel setting section 26 that specifies the channel of the receiver R is applied to the channel data judgment section 24, and when this setting value matches the channel data from the reception data memory section 23, the channel data judgment section 24
A match signal is output from. Control data determination unit 2
5 determines whether the control data is individual on/off signals _SE , _SF , simultaneous on/off signals _SA , _SB , or status confirmation signal _SI , and outputs accordingly. The output of the control data determining section 25 drives a load switching control section 27 such as a relay to open and close the load, and displays the control state on the display section 28. When the status confirmation signal S _I is transmitted to the receiver R, the on/off status of the load is inputted to the reply data creation unit 29 through the display unit 28. The response data creation section 29 inputs the on/off state of the load as response data from the output of the control data determination section 25 or the output from the display section 28 to the encoding section 22. Modulate and transmit T
It is sent back as a return signal Rt.

Next, the operation of this embodiment will be explained. First, transmitter T
Then, in order to transmit the confirmation signal S _I of all channels every 3 to 5 minutes, the confirmation signal timer section 5 inputs its output to the signal discrimination section 7, and transmits the transmission channel discrimination section 8 and channel data creation section 10. Channel data for all channels that can be connected to the transmitter T are written to the transmission data memory section 11 via the transmission data memory section 11, and confirmation data for the confirmation signal S _I created by the control data creation section 9 is written to the transmission data memory section 11. will be written to. From this transmission data memory section 11, a start signal St, a channel signal
Start data, channel data, and control data corresponding to Ch and control signal Cn are commercial power supply
The transmission signal Tr is read out one bit at a time every half cycle of AC and is sent to the power line L via the encoder 12 and modulator/demodulator 13 with the carrier wave controlled intermittently. On the other hand, the return signal Rt indicating the on or off load control state from the receiver R is transmitted via the modulation/demodulation section 13 and the decoding section 14 to the return signal Rt.
The response data determining section 15 displays a display corresponding to the on/off state on the display section 17, and the response channel memory section 16 displays whether the response is on or off. It stores the channel of the receiver R to which the signal Rt was sent back. Next, when transmitting the simultaneous on/off signals S _A and _SB for simultaneous control, the transmission channel determining section 8 determines the channel actually connected to the power line L based on the memory contents of the response channel memory section. Then, channel data equivalent to this channel is created in the channel data creation section 10, and the created channel data is stored in the transmission data memory section 1.
Store it in 1. At this time, the control data creation section 9 creates control data for all-on or all-off, and similarly stores it in the transmission data memory section 11.
The channel data and control data stored in this manner are sequentially read out, and the loads on the receivers R are simultaneously controlled via the encoder 12 and the modulator/demodulator 13. At this time, the control status is displayed on the display section 7 by the return signal Rt from the receiver 12 that has received the simultaneous on/off signals S _A and _SB .

On the other hand, in the receiver R, the channel data and control data in the transmission signal Tr are sequentially demodulated via the modulation/demodulation section 20 and the decoding section 21 and are stored in the received data memory section 23. Here, if the channel set by the channel setting unit 26 and the received channel data are equal, the control data determining unit 2
5 determines the control data, and depending on whether the control data is on or off, displays it on the display section 28 and opens and closes the load switching control section 27,
A signal for creating an on or off return signal Rt is input to the reply data creation section 29. Further, when the status confirmation signal S _I is received, a signal indicating the on or off status is received from the display unit 28, and the return data creating unit 29 generates return data indicating the status of the display unit 28. Note that when the status confirmation signal S _I is received, the display section 28 and the load switching control section 27 do not operate and maintain the previous state.

In the embodiment described above, the transmitter T and the receiver R are connected at a relatively short distance, so that the receiver R can receive the transmission signal Tr from the transmitter T, and the receiver R can receive the transmission signal Tr from the transmitter T.
An example has been shown in which the transmitter T is in a state where it can receive the return signal Rt from the transmitter. Next, as a second embodiment of the present invention, the distance between the transmitter T and the receiver R is long, and the signal transmission Here is an example in which the transmitter T is divided into a parent transmitter P and a relay transmitter I, and the relay transmitter I relays the signal from the parent transmitter P and transmits it to the receiver R in order to improve the reliability of the transmitter T. show. As shown in FIG. 4, the relay transmitter I is placed at a position away from the receiver R within the receivable range of the transmission signal Tr from the parent transmitter P. FIGS. 11 and 12 show block diagrams of a parent transmitter P and a relay transmitter I, respectively. The parent transmitter P has a zero cross detection section 1, a clock generation section 2, an individual operation section 4, a simultaneous operation section 6, and
Although it includes a transmission data memory section 11, a modulation/demodulation section 13, a display section 17, etc., the confirmation signal timer section 5 and response channel memory section 16 are omitted. Therefore, the parent transmitter P transmits the control signal Cn
The individual on/off signals S _E , _SF and the simultaneous on/off signals S _A , S _B are output as follows, but the status confirmation signal S _I
is not output. Relay transmitter I is the 12th
As shown in the figure, like the parent transmitter P, a zero cross detection section 30, a clock generation section 31, a modulation/demodulation section 32,
It includes an encoding section 33, a decoding section 34, and the like. The transmission data converted corresponding to the transmission signal Tr via the modulation/demodulation section 32 and the decoding section 34 is stored in the received data memory section 35 for one channel at a time. In this way, the received data memory section 35
The transmission data stored in is divided into channel data, control data, and reply data and sent to channel data determination section 36 and control data determination section 3, respectively.
7. The reply data is input to the reply data determination unit 38, where the channel, control content, and control state are determined.The content of each data is stored in the relay data memory unit 39, and this content is further read out and sent to the channel data creation unit. 40 and control reply data creation section 41
is input, and the channel data creation unit 40 creates channel data for accessing the specified channel, and the control reply data creation unit 41
Then, when the transmission data is sent to the parent transmitter P, reply data is created, and when the transmission data is sent to the receiver, control data is created. On the other hand, this relay transmitter I is provided with a confirmation signal timer section 42 and a confirmation data creation section 43 that uses its output to create confirmation data corresponding to the status confirmation signal S _I. Similar to the transmitter T shown in FIG. 9, confirmation data corresponding to the status confirmation signal S _I for all channels is created at predetermined time intervals. Channel data, control data, reply data, and confirmation data are all stored in the transmission data memory unit 44, read out, and transmitted to the parent transmitter P or receiver R via the encoder 33 and modulator/demodulator 32. The receiver R in this embodiment is the same as that shown in FIG.

Next, the operation of this embodiment will be explained. Here, for convenience, the number of channels that can be connected is assumed to be 16, and the number of channels that are actually connected is assumed to be 6. As shown in FIG. 13, a transmission signal Tr with a status confirmation signal S _I as a control signal Cn is transmitted from a relay transmitter I to all connectable channels at a constant period of about 3 to 5 minutes. A return signal R _t indicating the load status returned from the receiver R actually connected to the power line L using the status confirmation signal S _I is stored in the relay data memory section 39 of the relay transmitter I. In this state, when the simultaneous operation section 6 of the parent transmitter P is operated to perform simultaneous load control, the transmission signals r of all 16 channels are sequentially transmitted from the parent transmitter P to the relay transmitter I. Depending on the load state stored in the relay data memory section 39 of the relay transmitter I, the transmission signal Tr is transmitted only to the six channels that have returned the return signal Rt. At this time, the return signal Rt sent back from the receiver R is transmitted again to the parent transmitter P via the relay transmitter I, and the display 1 of the parent transmitter P
7 to display the load control status. As described above, when the access time per channel is t, the number of channels actually used in the present invention is always 48t when the number of channels is 16 in the conventional system during simultaneous control. The control time can be shortened by requiring only 28t for 6 and 30t for 7.

FIG. 14 shows a third embodiment of the present invention, in which a load control state memory section 45 is provided in place of the response channel memory section 16 of the transmitter T in FIG. In other words, the response channel memory section 16 stores the channel on which the return signal Rt from the receiver R was received, but the load control state memory section 45 simultaneously records whether the load is on or off. It is something to remember. Therefore, during simultaneous control, only channels in a control state different from the current control state are accessed. That is,
When the simultaneous on signal S _A is used as the control signal Cn, the channels whose loads are on are not accessed, and among the receivers R actually connected to the power line L, only the channels whose loads are off are accessed. to turn them on. In the above embodiment, the transmission signal Tr is directly transmitted from the transmitter T to the receiver R.
The transmitter T is divided into the parent transmitter P and the relay transmitter I, and the load control state is stored in the relay data memory section 39 of the relay transmitter I as shown in FIG. It is okay to do so.

FIG. 15 is a block diagram showing a transmitter T according to a fourth embodiment of the present invention, in which a load control state memory section 45 of the transmitter T shown in FIG. 14 is further connected to an unresponsive channel memory section 46. A channel determination section 47 is added. That is, the unresponsive channel memory section 46 stores channels that are not connected to the power line L based on the contents of the load control state memory section 45. At the time of simultaneous control, immediately after transmitting the control signal Cn for simultaneous control, a status confirmation signal S is sent only to the channels stored in the unresponsive channel memory section 46.
If there is a channel that has transmitted _I and has newly returned a return signal Rt, the control signal Cn is transmitted again only to that channel through the connection channel determination section 47.

This operation will be explained. For example, as shown in Fig. 16, the receivers R of channels 1, 2, 5, 10, 15, and 16 are first connected, and after the status confirmation signal St is transmitted, the simultaneous on/off signals S _A , S _B Assume that a new 8-channel receiver R is connected before the data is transmitted. This 8 channel receiver R
Since it was not connected when the status confirmation signal S _I was transmitted, it is stored as an unresponsive channel in the unresponsive channel memory unit 46 along with other unresponsive channels. Here, when performing simultaneous control, 1, 2, 5, 10, which were connected from the beginning,
Load control is performed on channels 15 and 16, but 8
Channels are not controlled. Immediately following the simultaneous on/off signals S _A and S _B , a status confirmation signal S _I is transmitted only for the channels stored in the unresponsive channel memory section 46 as shown in FIG. A return signal Rt is also sent back from R. In this way, if the load of the receiver R that has returned the return signal R _t in response to the second status confirmation signal S _I is in a different control state from the control state corresponding to the first control signal, the return signal R t is returned as the first control signal. The same type of signal is sent back to the later connected 8
Channels are also subject to load control. However, if the load is in a control state corresponding to the first control signal from the beginning, no control signal is transmitted. That is, when the all-off signal S _B is initially transmitted, if the load of the receiver R connected later is in the off state, it will not be accessed. still,
Of course, the relay transmitter I may also be used in this embodiment. By doing the above, only the channel of the receiver R that is actually connected is accessed at first, so the cycle time from operation to control is shortened, and at the same time, it is checked whether there is any connected channel. ,
Control is ensured.

As described above, the present invention sends out a status confirmation signal from the transmitter at predetermined time intervals, stores the channel from which the return signal was sent, and accesses only the channels of the receivers actually connected to the power line during simultaneous control. This has the advantage that unnecessary channels are not accessed and the time from transmission to control can be shortened. , the relay transmitter sends out a status confirmation signal and the relay transmitter memorizes the channel of the receiver connected to the power line, so the time from transmission to control can be shortened compared to conventional systems, and the relay transmitter can Since the signal is relayed by , it has the advantage that the transmission distance can be extended. Furthermore, the transmitter stores the control state of the load using the return signal in response to the status confirmation signal, and during simultaneous control, the control state of the load among the receivers connected to the power line is different from the state that should be achieved by the control signal. A device that accesses only the channel of a receiver that is in a state of control has the advantage that the cycle time until control can be further shortened, and control is ensured because it is controlled according to the control state of the load, and simultaneous control is possible. Immediately transmit the status confirmation signal again to the receivers that did not respond to the status confirmation signal after that, and among the receivers that responded, the load control status does not correspond to the previous simultaneous control signal. By transmitting the same control signal as the previous control signal only to the control signal, not only can the cycle time until control be shortened, but also if the control signal is connected to the power line between the first status confirmation signal and the control signal. The receiver can also be operated reliably and its reliability can be improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the power line carrier control system according to the present invention, Fig. 2 is an operation explanatory diagram showing the signal configuration of the same, Fig. 3 is a schematic configuration diagram of an embodiment of the same, and Fig. 4 is the same as the above. FIGS. 5a and 5b are operation explanatory diagrams showing signal transmission states during individual control and simultaneous control in the conventional example, respectively. FIG. 6 is an operation showing the signal configuration of the present invention. An explanatory diagram, FIG. 7 is an operation explanatory diagram showing the relationship between the commercial power supply and the transmission signal as above, and FIGS. Explanatory drawings: FIG. 9 is a block diagram of a transmitter used in the first embodiment of the present invention, FIG. 10 is a block diagram of a receiver used in the same, and FIG. 11 is a second embodiment of the present invention. 12 is a block diagram of the relay transmitter used in the above, FIG. 13 is an operation explanatory diagram showing the relationship between the status confirmation signal and control signal in the above, and FIG. 14 is a block diagram of the relay transmitter used in the above. A block diagram of a transmitter used in a third embodiment of the invention,
FIG. 15 is a block diagram of a transmitter used in the fourth embodiment of the present invention, FIG. 16 is a schematic configuration diagram of the same as above,
FIG. 17 is an operation explanatory diagram showing the signal state as above, where R is a receiver, T is a transmitter, L is a power line, P is a parent transmitter, I is a relay transmitter, Cn is a control signal, and R _t
is a return signal, and S _I is a status confirmation signal.

Claims (1)

[Claims] 1. A control signal from a transmitter connected to a plurality of receivers each having an individual channel via a power line to control a load connected to each receiver and to determine the control state thereof. This is an answer-back type control method in which a return signal is sent back to the transmitter, and the return signal for the status confirmation signal is cyclically transmitted from the transmitter to each receiver at predetermined intervals to confirm that the power line is actually connected. A power line carrier characterized in that the channel of each receiver connected to the power line is memorized by the transmitter, and only the receivers connected to the power line are accessed when the loads of all receivers are controlled simultaneously with the same control signal. control method. 2 The transmitter has a main transmitter that has an operating section, and a relay transmitter that creates a status confirmation signal and transmits it to the receiver, receives a return signal from the receiver, and stores the channel of the receiver connected to the power line. The relay transmitter is connected to the parent transmitter and the receiver via a power line within the signal transmission range of the parent transmitter and receiver, and the relay transmitter is connected to the parent transmitter and the receiver via a power line to transmit control signals from the parent transmitter to the receiver and the receiver. The return signal from the main transmitter to the main transmitter is amplified and transmitted within the relay transmitter, and when the main transmitter is operated to control the loads of all receivers at the same time with the same control signal, the relay transmitter is connected to the power line. 2. The power line carrier control method according to claim 1, wherein the control signal is relayed by accessing only the channel of the receiver connected to the receiver. 3 A control signal from a transmitter connected to a plurality of receivers each having an individual channel via a power line controls the load connected to each receiver, and transmits the control state as a return signal to the transmitter. This is an answer-back type control system in which each receiver actually connected to the power line is channeled by a return signal in response to a status confirmation signal that is cyclically transmitted from the transmitter to each receiver at predetermined intervals. At the same time, the load control state of the receiver is memorized by the transmitter, and when the loads of all receivers are controlled simultaneously with the same control signal, the control state of the load among the receivers connected to the power line is stored in the transmitter. A power line carrier control method characterized in that only receivers in a state different from the control state corresponding to the signal are accessed. 4 When controlling the loads of all receivers simultaneously with the same control signal, only those receivers connected to the power line whose load control state is different from the control state corresponding to the control signal are controlled. Immediately after accessing and transmitting the control signal, the status confirmation signal is transmitted again only to the receiver that did not return the return signal in response to the previous status confirmation signal, and at this time, if there is a receiver that has sent the return signal and Claim 1, characterized in that the same control signal as the previous control signal is transmitted only when the control state of the load of the receiver that has been returned is different from the control state corresponding to the previous control signal. The power line transport control method described in Section 3.