JPS60140950A - Data transmission method between controller - Google Patents

Abstract

PURPOSE:To attain low cost by using two connecting lines between controllers so as to transmit data between the controllers. CONSTITUTION:A level converting section 9 of the controller 1 superimposes a data signal 11 from a judging section 3 onto a power line 6. The signal 11 is taken as a voltage amplitude modulation signal changed by a voltage more than a drive power supply voltage of the controller 2. Moreover, a level converting section 10 separates a power supply a power supply transmitted on a transmission power line 12 and a data signal and applies separately the power supply and the data signal separately to a judging section 4. The judging sections 3, 4 are microcomputers and energized from a power supply section 5. The converting section 9 is a device at the transmission side converting the voltage level of the transmission power line 12 into tri-state voltage levels by the output combination of the judging section 3 and the converting section 10 is a device at the reception side comprising a power supply extracting circuit and a signal separating circuit. Then the judging section 4 discriminates the tristate voltage values of the power supply line 12 so as to decode the transmission data from the controller 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to applications between two or more electronic control devices that are separated from each other and require data transmission while performing independent control, for example, air conditioning. The present invention relates to a data transmission method between an indoor unit control device and a remote control device of a machine, or between an indoor unit control device and an outdoor unit control device.

Conventional configuration and its problems 2.\-7 Conventionally, data transmission between two mutually independent control devices, each having a power supply section only on one side, has been realized with a configuration as shown in FIG. Here, since the present invention relates to data transmission, a detailed explanation of the control method and control object in the determination unit will be omitted.

In FIG. 1, reference numerals 1 and 2 are independent control devices, both of which perform data transmission, control, etc., and each of which has a judgment section 3, 4 realized by a microcomputer or the like. Further, the control device 1 has a power supply unit 6 connected to the control device 2 via a Hegeland wire 7 and a power supply line 6. Further, the determining section 3 and the determining section 4 are connected via a data transmission line 8 that actually performs data transmission.

In this way, conventionally, the control device 1 and the control device 2 are connected to the power supply line 6. Ground wire7. The determination unit 4 of the control device 2 receives power from the power supply unit 6 and receives serial data etc. through the data transmission line 8. It was intended to exercise appropriate control.

However, in this configuration, the connection line between the control devices is 6°7.8
Since there are three lines, the distance between the control devices is long.
When the number of control devices increases, there is a drawback that cost and workability become problems.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks seen in the above-mentioned conventional examples and uses two connecting wires between control devices to reduce costs and facilitate construction.

Structure of the Invention In order to achieve this object, the present invention provides data transmission between a plurality of control devices, a control device having a power supply for supplying power to each control device, and a control device receiving power supply from the control device. Data transmission is performed by superimposing the transmission signal on the power supply wire as a voltage amplitude modulation signal that has at least three voltage values and changes at a voltage higher than the driving power supply voltage of the control device on the power supply side. It is something.

DESCRIPTION OF THE EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings published in Japanese Patent Application Laid-Open No.
O-140950(2) This will be explained with reference to FIGS. 2 to 5.

First, the configuration of this embodiment will be explained with reference to FIG. Components that are the same as those in FIG. 1 are given the same numbers and their explanations will be omitted.

In the figure, reference numerals 9 and 10 indicate level conversion units, and one level conversion unit 9 superimposes the data signal 11 from the determination unit 3 on the power supply line 6 from the power supply unit 6. The other level conversion section 1o separates the power and data signals transmitted by the transmission power line 12, and separately supplies the power and data signals to the determination section 4.

Next, referring to FIG. 3, the circuit configuration of the level converters 9 and 10 will be explained.

In the same figure, the determination unit 3.4 is a microcomputer, and both are supplied with power from the power supply unit 6 of the control device 1. Hereinafter, the determination units 3 and 4 will be referred to as microcomputers.

Here, the control device 10 level converter 9 converts the transmission power line 1
This is the transmitting side that converts two voltage levels into three voltage levels. That is, 13 is a resistor for bias 5...-7, 14, 15.16 is a Zener diode for voltage level setting, 17, 18.19 is a buffer transistor, and 2o is a switching transistor. The voltage level of the transmission power line 12 is determined by the output combination of the microcomputer 3, and the voltage level of the buffer transistors 17, 1
8.19 is turned on, current flows through either of the voltage level setting Zener diodes 14, 15.16, the switching transistor 2o is biased, and a determination is made.

Further, the level converter 10 of the control device 2 is a receiving side that is composed of a power supply extraction circuit and a signal separation circuit. As the former, the diode 21. Resistor 22° Capacitor 23.
It is composed of a Zener diode 24 for voltage setting, and generates power to be supplied from the transmission power line 12 to the microcomputer 4 and voltage comparators 25 and 28. The resistors 27 and 28 divide the stabilized power supply voltage and set a voltage at the negative input terminal of the voltage comparator 26. Similarly, resistors 29 and 30 set the voltage comparator 26 at a voltage setting of 6.
Do page. Resistors 31 and 32 divide the voltage of the transmission power line 12,
It is input to the positive input terminal of voltage comparator 25,26. That is, the voltage level of the transmission power line 12 is compared with a preset reference voltage, and the comparison result is outputted to the input of the microcomputer 4. The microcomputer 4 uses the combination of the outputs of the voltage comparators 25 and 26 to
It discriminates the three-value voltage value of the transmission power line 12 and decodes the transmission data from the microcomputer 3 of the control device 1.

Next, FIG. 4 shows the voltage waveform on the transmission power supply 12, the input IN of the microcomputer 4, 1. The decoding of the transmitted data will be explained with reference to FIG. 6, which shows the waveform of IN2.

In FIG. 4, level 1 is microcomputer 4,
This is the power supply voltage level necessary to drive the voltage comparators 26 and 26, and is defined by the Zener diode 24. Level 2 is the negative input voltage level of voltage comparator 26 and is set by resistor 29.30. Similarly,
Level 3 is the negative input voltage level of voltage comparator 26, resistor 27.
It is set by 28. The solid line shows the waveform on the transmission power line 12, and the one-dot chain line shows the waveform after being voltage-divided by the resistors 31 and 32.

In other words, the voltage comparator 25 performs a voltage comparison between the level 2 and level 3 voltages and the dot-dash line voltage indicating the transmission voltage waveform after voltage division.
．． 26 and is taken in as an input to the microcomputer 4.

FIG. 6 shows the waveforms of the output of the voltage comparator 26, ie, the IN1 power of the microcomputer 4, and the output of the voltage comparator 26, ie, the IN2 power of the microcomputer 4.

That is, if the voltage on the transmission power line 12 is higher than the power supply voltage (level 1) of the control device 2, data transmission is possible.

In this embodiment, the inputs IN1 . Data communication was performed using a time series input combination of IN2.

In this embodiment, data transmission between one control device is explained, but data transmission between one control device and a plurality of control devices is also possible. In addition, although three values are used as the transmission signal voltage values, the same implementation can be achieved even if the transmission signal voltage values are three or more values. In addition, if you use one voltage value as a trigger input and transmit a data signal at another level, or use one voltage value as a signal indicating that transmission is in progress and transmit data at another voltage level, external noise can be avoided. In addition to preventing the occurrence of erroneous reception due to errors such as the following, the same effects as in this embodiment can be achieved.

Effects of the Invention As is clear from the above embodiments, the data transmission method between control devices according to the present invention allows the voltage value of the power line that is originally required between a plurality of control devices to be changed at least to the voltage value of the control device on the power receiving side. By transmitting data using a voltage amplitude modulated signal with a voltage higher than the power supply voltage and a voltage with three or more values, the number of connection wires can be reduced, reducing costs and improving workability.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram of a conventional control device, Fig. 2 on page 9 is a block circuit diagram of a control device implementing the present invention, and Fig. 3 is an electronic circuit diagram centered on the level conversion section in the same control device. FIG. 4 is a voltage waveform diagram on the transmission power line in the control device, and FIG. 6 is a data transmission signal diagram after data reception in the control device. 1.2...Control device, 6...Power supply, 1
2...Electric wire for power supply.

Claims (1)

[Claims] A data transmission signal between a control device equipped with a power supply for supplying power to the control device and a control device receiving power supply from the control device has at least three voltage values, and further has a control device on the side to which the power is supplied. A data transmission method between control devices in which a voltage amplitude modulation signal that changes with a voltage higher than the drive power supply voltage of the device is superimposed on a power supply wire.