JPS60165126A - Data carrier system in power line carrier control system - Google Patents

Abstract

PURPOSE:To ensure noise prevention and limit of application of current and also load control by superimposing a carrier from a transmitter on a position except a zero cross point and its vicinity of a power frequency to transmit the carrier. CONSTITUTION:A zero cross point is detected by the input of a zero cross point detecting signal from a zero cross detecting section 233, the period at each bit is picked up and after 3ms is elapsed from the detection of the trailing of the signal, the carrier is controlled so as to be transmitted for, e.g., 4ms. Then the control above is performed until the transmission data does not exist any more. A signal on the center part of which the carrier is superimposed except the zero cross point and its vicinity of the AC frequency is outputted from a transmitter 23. Since a receiver receiving such signal has no carrier at the zero cross point and its vicinity, the zero cross point is detected from the power waveform only and a 1 pulse of zero cross point detecting signal is generated. Thus, the load is controlled always in synchronization with the zero cross point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a data transmission method in a power line transport control system that performs data transmission using, for example, an indoor power line.

[Technical background of the invention and its problems] For example, in a power line carrier control system that transmits data using indoor power lines, as shown in FIG. At the same time, a plurality of receivers 4-1, 4-2, . -n and performs data analysis, each with a load of 5-1.5-2
, . . 5-n are controlled. in this case,
As shown in FIG. 2(a), the transmitter 3 sends a start flag STF indicating the start of communication, a command CMD indicating control details, an address ADR indicating the reception channel, and a checksum C3M for confirming reliability. send the data,
The receivers 4-1 to 4-n that received this data send an acknowledge signal, which is a response signal, as shown in FIG. 2(b).
K is sent to the transmitter 3 side.

Incidentally, in such a system, a zero-cross control method is used to prevent noise, limit input current, and the like. The principle of this zero-cross control method is to minimize transient current changes by turning the load on and off at the zero point of the AC voltage. Specifically, for example, as shown in FIG. 3, a zero cross detection circuit 6 is connected to the AC type I 11 via a power line 2, and a load 8 is connected via an on/off circuit 7. Switch 9 is connected to. As shown in FIG. 4, the zero-cross detection circuit 6 is connected to the AC power source 1 through a transformer 10 to a full-wave rectifier circuit 11, and to the full-wave rectifier circuit 11 a diode 12 and a resistor 13 are connected in series. A diode 14 is connected, and a transistor 16 is connected to the Zener diode 14 via a resistor 15. Further, a series voltage dividing circuit including resistors 17 and 18 is connected to the full-wave rectifier circuit 11, and the voltage dividing point thereof is connected to the base of the transistor 16. Note that the Zener diode 14
A capacitor 19 is connected in parallel.

In this device, the zero-crossing detection circuit 6 detects the AC power frequency as a full-wave waveform A through the transformer 10 and the full-wave rectifier circuit 11 as shown in FIG. When the base voltage is lower than Ton, it is turned off, and when it is higher than Ton, it is turned on to detect the waveform and output a one-pulse zero-crossing point detection signal. When the switch 9 is turned on, the on/off circuit 7 controls the operation of the load 8 at the timing when the zero-cross detection signal is supplied from the zero-cross detection circuit 6.

However, in conventional power line carrier control systems that use such a zero-crossing control method, as shown in Figure 6, carrier waves are transmitted by superimposing them over the entire AC power frequency range, so the zero-crossing point and its vicinity are (Part A in Figure 6) As shown in Figure 7, the voltage applied to the base of the transistor 16 increases and decreases the Ton level many times due to the carrier wave, so zero cross detection is performed with only one pulse. This causes problems such as the number of pulses is reduced to several, making it impossible to detect the correct zero-crossing point, and making noise prevention and current limiting incomplete. Additionally, there is a risk of malfunction in load control.

[Purpose of the Invention] This invention was made to solve these problems, and it is possible to reliably perform zero cross detection with one pulse, ensure noise prevention and limit the input current, and improve load control. The purpose of the present invention is to provide a data transport method in a power line transport control system that can reliably ensure the following.

[Summary of the Invention] The present invention connects a transmitter and a receiver to a power line of a commercial AC power source, superimposes a high frequency signal data-processed from the transmitter on the power frequency as a carrier wave, and transmits it on the power line. In a power line carrier control system that receives the carrier wave and performs load a control based on the zero-crossing point of the power supply frequency, the carrier wave from the transmitter is superimposed on the position excluding the zero-crossing point of the power supply frequency and its vicinity. The purpose is to transport the vehicle.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 8, a power line 22 is connected to a commercial AC power source 21. As shown in FIG. A transmitter 23 is connected to the power line 22. The transmitter 23 includes a coupling section 231, a transmitting section 232,
Clock detection section 233, keyboard 234, display section 23
The transmission section 232 is controlled by the microprocessor 236 and outputs a data-processed signal to the power line 22 as a carrier wave via the coupling section 231.

The zero-crossing detection section 233 detects the zero-crossing point of the power supply frequency using the same principle as described in FIG. 4, and supplies the zero-crossing point detection signal to the microprocessor 236. The microprocessor 236 performs program control based on the flow factors shown in FIG. That is, first, the sending data is prepared, then the zero-crossing point is detected by inputting the zero-crossing point detection signal from the zero-crossing detection section 233, synchronization is established for each bit, and the falling edge of the signal is detected. After waiting for the elapsed time, control is performed to transmit the carrier wave for, for example, 4 ms. The above control is continued until there is no more data to send. The keyboard 234 forms an input section for signals that give instructions to the transmitter 23, and the display section 235 displays the operating status of the receiver 1jlH (not shown).

In the device according to the embodiment of the present invention configured in this manner, for example, if the power supply frequency is 50 Hz, the carrier wave is transmitted at the time interval (
(b) in Fig. 10 with a delay of 3 ms.
), it is transmitted for only 4 ms in between. As shown in FIG. 11, the transmitter 23 outputs a signal excluding the zero-crossing point of the AC frequency and its vicinity, in other words, carrying the carrier wave in the center. Therefore, since there is no carrier wave at or near the zero-crossing point in a receiver receiving such a signal, the zero-crossing point can be detected only from the power supply waveform, and as described in Figure 5, the zero-crossing point can be detected only from the power supply waveform.
A pulse zero-crossing point detection signal is generated.

Therefore, load control is always performed in synchronization with the zero-crossing point, ensuring noise prevention and limiting the input current, and also ensuring that the load side (2) does not malfunction.

Next, another embodiment of the invention will be described with reference to the drawings.

Note that the same parts as in the above embodiment are given the same reference numerals, and detailed explanations will be omitted.

As shown in FIG.
7 is provided, and a coupling section 241 and a transmitting section 2 are further connected to the power line 22.
42, a receiving section 24 consisting of a zero-cross detecting section 243, a receiving section 247, and a microprocessor 246 is connected. A relay 244 is connected to the microprocessor 246, and a series circuit of a light emitting diode 245 and a resistor 248 is also connected. A load 25 is connected to the power line 22 via a normally open contact m of the relay 244. A coupling section 241 of the receiver 24, a transmitting section 242,
The zero cross detection section 243 and the reception section 247 are connected to the receiver 2.
3 coupling section 231, transmitting section 232, zero cross detecting section 2
33 and has the same configuration as the receiving section 237. As shown in FIG. 13, the receiving sections 237 and 247 detect a carrier wave on an alternating current frequency, generate a pulse-like signal (No. 8), and supply it to the microprocessor 236 and 246. The receiving section 2
When the received signal from 47 is received, the number of pulses is counted, and when the number of pulses is greater than a preset value (Fig. 13, b)), it is set to, for example, "1", and when it does not reach the predetermined value, the number of pulses is counted. ((a) in FIG. 13) is determined as "O". Of course, the carrier wave sending method in the transmission 1M23 is the same as in the embodiment described above.

With such a configuration, the zero-crossing point can be reliably detected by the receiver 24 with one pulse as in the embodiment described above, and the same effect as described above can be obtained by 1q.

Furthermore, in this embodiment, when a carrier wave is received, it is converted into a pulse signal and the number of pulses is set to 1, and the number of pulses is set in advance using a statistical method as shown in the histogram based on the counted values in FIG. If the value is not greater than the specified value, “
1" signal, so even if noise mixes into the AC frequency, it will be determined as rOJ, so there will be no malfunction due to noise. Further, even if the frequency of the carrier wave changes slightly, there is no adverse effect due to it. Furthermore,
Since rOJ and r1J can be determined not only in bits but also in many ways, it is possible to code and transfer high-density data, thereby improving line utilization efficiency.

``Effects of the Invention'' As detailed above, according to the present invention, zero cross detection can be reliably performed with one pulse, noise can be prevented, input current can be restricted, and load control can be ensured through power line transport. It is possible to provide a data transport method in a serial control system.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the power line carrier control system, Fig. 2 is a diagram showing the configuration of the carrier signal, Fig. 3 is a block diagram for explaining the zero-cross control method, and Fig. 4 is the zero-cross detection in Fig. 3. A circuit diagram showing the configuration of the circuit, FIG. 5 is a waveform diagram to explain zero-cross detection, FIGS. 6 and 7 are waveform diagrams to explain the problems of conventional carrier wave detection, and FIG. 9 is a flowchart showing a microprocessor control program in the embodiment; FIG. 10 is a waveform diagram showing the timing of superimposition of a zero-cross detection signal and a carrier wave in the embodiment; FIG. FIG. 11 is a waveform diagram showing a superimposed signal of an AC frequency signal and a carrier wave in the same embodiment, FIG. 12 is a circuit diagram showing another embodiment of the present invention, and FIG. 13 is a waveform diagram showing an AC frequency signal and a carrier wave in the same embodiment. FIG. 14 is a waveform diagram showing the relationship between the superimposed signal and the carrier detection signal and the code, and FIG. 14 is a histogram statistically showing the relationship between the carrier detection signal and the code in the same embodiment. 21...Commercial AC power supply, 22...Power line, 23...
- Transmitter, 231... coupling section, 232... transmitting section,
233...Zero cross detection unit, 236...Micro processor v124...Receiver, 25...Load. Applicant's agent Patent attorney Takehiko Suzue No. 1 [1 No. 2r'1 (a) (b) Fig. 4 Fig. 5 Fig. 6 N No. 7- Fig. 10 22 No. 12r71

Claims (1)

[Claims] A transmitter and receiver were connected to the power line of a commercial AC power source, and data from the transmitter was processed. Superimposing a high frequency signal as a carrier wave on the power supply frequency and transmitting it on the power line,
In a power line carrier control system in which the receiver receives the carrier wave and performs load control based on the zero-crossing point of the power frequency, the carrier wave from the transmitter is located at a position excluding the zero-crossing point of the power frequency and its vicinity. A data transport method in a power line transport control system that is characterized by superimposing data on and transporting data.