JPH026259B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides communication between a transmitter and a receiver using a phase pulse injected into an AC power wave of a low-voltage power distribution line or dedicated line, or a continuous frequency signal (for example, a ripple control signal). This invention relates to improvements in signal transmission methods for transmitting information between

As shown in FIG. 1, the conventional phase pulse signal conveying method uses an AC power wave 1 for conveying a low-voltage power distribution line.
A plurality of, for example, 10 channels CH1 to CH10 are set in the low noise region 2 of , the receiver performs a predetermined operation such as sending back data by receiving the phase pulse signal 3 that matches its own address code. Then, in order to separate the phase pulse signal 3 from standing noise synchronized with the phase of the carrier AC power wave 1 and random noise that is not synchronized, the carrier AC power wave 1 is transmitted for a predetermined number of cycles (for example, several seconds). Multi-continuous transmission is performed in which phase pulse signal 3 is repeatedly injected. However, if there is a lot of noise, transmission errors may occur even if multiple transmissions are performed.

An object of the present invention is to solve the above-mentioned problems and to provide a signal transport method that can reliably communicate signals between a transmitter and a receiver even when there is a lot of noise in the carrier AC power wave. It is to provide.

In order to achieve this objective, the present invention sets a signal cycle and a noise detection cycle between the signal cycles in the cycle of the carrier AC power wave,
The transmitter injects a signal into the signal cycle and no signal into the noise detection cycle, and the receiver subtracts the noise waveform detected in the immediately preceding or following noise detection cycle from the received waveform received in the signal cycle. The signal is detected by averaging the subtracted values every predetermined number of signal cycles, and the standing noise is removed by the subtraction immediately after every signal cycle, and after a predetermined number of signal cycles, the signal is detected. The method is characterized in that random noise is removed by the averaging.

Hereinafter, the present invention will be explained in detail with reference to FIGS. 2 to 5.

2 to 4 are diagrams illustrating an embodiment of the present invention using a phase pulse signal as a signal. Components similar to those in FIG. 1 are designated by the same reference numerals. In FIG. 2, a signal cycle 4 and a noise detection cycle 5 are alternately set in the cycle of the carrier AC power wave 1. The transmitter injects phase pulse signal 3 only in signal cycle 4 and does not inject phase pulse signal 3 in noise detection cycle 5. The receiver performs a receiving operation in signal cycle 4 and noise detection cycle 5. FIG. 3 shows an example of the receiver, and FIG. 4 shows a time chart of its operation.

First, to explain the operation in signal cycle 4,
A filter 7 separates a received waveform 8 (FIG. 2) of a phase pulse signal 3 containing noise from a carrier AC power wave 1 inputted to an input terminal 6. Each channel CH
1 to CH10 are subdivided into phase units U1 to U10, respectively, as shown in FIG.
The A/D converter 9 converts the received waveform 8, which is the analog output of the filter 7, into digital values D1 for each phase unit U1 to _U10 according to a command from the control circuit 10, and stores these digital values _D1 in the memory 11. remembers.

Next, in the noise detection cycle 5, the filter 7 detects the noise waveform 12, and the A/D converter 9 converts the noise waveform 12 into digital values _D2 for each phase unit U1 to U10, and these digital values _D2 is stored in the memory 11.

At the end of the noise detection cycle 5, the arithmetic unit 13
subtracts the digital value D ₂ of the noise waveform 12 from the digital value D ₁ of the received waveform 8 for each same phase unit of the same channel, and the memory 11 stores these subtracted values. This subtraction removes standing noise components.

After repeating this operation for a predetermined number of cycles 2S and storing S subtraction values in the memory 11 for each same phase unit of the same channel,
The arithmetic unit 13 averages the S subtraction values. As a result, random noise components are removed and only phase pulse signal 3 is extracted. Address code discriminator 1
4 determines whether the address code of the extracted phase pulse signal 3 matches its own address code, and when they match, sends out an output pulse from the output terminal 15.

In addition, signal cycle 4 and noise detection cycle 5
A noise detection cycle 5 may be provided every several cycles by adding a return signal cycle or the like for returning a signal from the receiver to the transmitter.
Further, the digital value of the noise waveform 12 to be subtracted from the digital value of the received waveform 8 is the digital value of the signal cycle 4.
It may be obtained from noise detection cycle 5 immediately before. If analog values are stored in the memory 11 and the arithmetic unit 13 and used for calculation, the A/D converter 9 becomes unnecessary.

FIG. 5 is a diagram illustrating another embodiment of the present invention using a continuous frequency signal as the signal. A signal cycle 4 and a noise detection cycle 5 are alternately set in the cycle of the carrier AC power wave 1. The signal cycle 4 and the noise detection cycle 5 are divided into four channels CH1 to CH4 and CH5. The transmitter injects a continuous frequency signal 16 into the channel depending on the information to be transmitted. In Figure 5,
An example is shown in which the transmitter injects continuous frequency signals 16 into channels CH1 and CH3 depending on the information to be transmitted (1010). In the receiver, each channel is subdivided into phase units U1 to Un.
The width of the phase unit is set to such a width that the waveform of the continuous frequency signal 16 can be reproduced. For example, if the frequency of the continuous frequency signal 16 is 10 KHz, it is preferably about 10 μs. The receiver converts the received waveform 17 in signal cycle 4 and the noise waveform in noise detection cycle 5 into digital values D ₃ (digital values of the noise waveforms are not shown) for each phase unit U1 to Un. , and store the subtracted value. After the subtracted values have been accumulated over a predetermined number of cycles, the continuous frequency signal 16 is detected by averaging them.

As explained above, according to the present invention, a signal cycle and a noise detection cycle between the signal cycles are set in the cycle of the carrier AC power wave,
The transmitter injects a signal into the signal cycle and no signal into the noise detection cycle, and the receiver subtracts the noise waveform detected in the immediately preceding or following noise detection cycle from the received waveform received in the signal cycle. The signal is detected by averaging the subtracted values every predetermined number of signal cycles, and the standing noise is removed by the subtraction immediately after every signal cycle, and after a predetermined number of signal cycles, the signal is detected. Since random noise is removed by the averaging, even if the carrier AC power wave contains a lot of noise, signal communication between the transmitter and the receiver can be performed reliably.

[Brief explanation of drawings]

FIG. 1 is a waveform diagram illustrating a conventional phase pulse signal transport method, FIG. 2 is a waveform diagram illustrating an embodiment of the present invention, and FIG. 3 is an example of a receiver implementing an embodiment of the present invention. FIG. 4 is a time chart showing the operation of the receiver of FIG. 3, and FIG. 5 is a waveform diagram illustrating another embodiment of the present invention. 1... Carrier AC power wave, 3... Phase pulse signal, 4... Signal cycle, 5... Noise detection cycle, 7... Filter, 8... Received waveform, 9...
A/D converter, 10... Control circuit, 11... Memory, 12... Noise waveform, 13... Arithmetic unit, 16
...Continuous frequency signal, 17...Received waveform, CH1~
CH10...Channel, U1~U10, Un...
Phase unit, _D1 to _D3 ...Digital value.

Claims (1)

[Claims] 1 In a signal transmission method in which a transmitter repeatedly injects a signal into a carrier AC power wave over a predetermined number of cycles of the carrier AC power wave, and a receiver detects the signal from the carrier AC power wave, A signal cycle and a noise detection cycle between the signal cycles are set in the power wave cycle, and the transmitter
A signal is injected into the signal cycle and no signal is injected into the noise detection cycle, and the receiver subtracts the noise waveform detected in the noise detection cycle immediately before or after the reception waveform received in the signal cycle from the received waveform received in the signal cycle, and calculates a predetermined number of signals. A signal conveying method characterized in that a signal is detected by averaging the subtracted values for each signal cycle.