KR20020057740A - Rs 422 communication circuit using relay - Google Patents

Abstract

PURPOSE: An RS-422 communication circuit using a relay is provided to make a circuit design simple and to maximize the efficiency of the circuit design by realizing the signal transfer while securing an operation current value of an opto coupler. CONSTITUTION: The RS-422 communication circuit comprises a data transmitter(110) transmitting the data, a driver(120) outputting the transmission signal according to the signal output from the data transmitter, and a plurality of relays(131-13n) connecting to an output terminal of the driver. A plurality of opto couplers(141-14n) receives the transmission signal output from the driver according to the driving of the relays by connecting to the output terminal of respective relays. A controller(150) outputs a control signal in order to control the operation of respective relays. A decoder(160) transfers the control signal to the corresponding relay according to the control signal output from the controller. A data receiver receives the signal output from respective opto couplers.

Description

RS sai communication circuit using relay {RS 422 COMMUNICATION CIRCUIT USING RELAY}

The present invention relates to an RS-422 communication circuit, and more particularly, a relay is added to a front end of a plurality of opto-couplers, and selectively relayed using a decoder for driving the relay. The present invention relates to an RS-422 communication circuit using a relay to guarantee an operating current value of an optocoupler by selectively applying a signal output from the data transmitter to the optocoupler by driving the optocoupler.

In general, a conventional RS-422 communication circuit includes a plurality of drivers for outputting a plurality of driving signals in accordance with a data transmitter 10 for transmitting data and a signal output through the data transmitter 10 as shown in FIG. 1. (21, 22, 23, ... 2n) and the output terminal of each driver (21, 22, 23, ... 2n) are driven in accordance with the drive signal output from the driver (21, 22, 23, ... 2n) and the signal A plurality of optocouplers (31, 32, 33, ... 3n) for transmitting a, and a data receiving unit 40 for receiving a signal output through the opto couplers (31, 32, 33, ... 3n).

When the RS-422 communication circuit outputs a signal in order to transmit the corresponding data from the data transmitter 10, each of the corresponding drivers 21, 22, 23, ... 2n generates and outputs a driving signal corresponding to this signal. The optocouplers 31, 32, 33,... 3n connected to the respective drivers 21, 22, 23,... 2n are operated, and according to the operation of the optocouplers 31, 32, 33,... The data is received at 30). The optocoupler has excellent ground separation function of the transmitting and receiving end, and has a good noise characteristic, which is widely used in communication circuits.

The opto-coupler of the conventional communication circuit uses a plurality of drivers because the signal is correctly transmitted only when the operating current value is guaranteed. However, when the plurality of drivers are used, the circuit design becomes complicated and the efficiency is lowered.

In addition, since such a communication circuit cannot select a channel, even if a signal is transmitted through a specific channel, signals are transmitted through all channels, thereby causing another problem of interference between adjacent channels.

Accordingly, an object of the present invention is to solve the above problems, and by simplifying the design of the circuit by selectively operating the optocoupler by using a relay to ensure the operation current of the optocoupler while ensuring signal transmission. In other words, the efficiency of the circuit design is maximized.

In addition, another object of the present invention is to block the occurrence of interference between adjacent channels because the signal can be transmitted only through a specific channel.

1 is a block diagram showing the configuration of a conventional RS-422 communication circuit.

2 is a block diagram showing the configuration of an RS-422 communication circuit using a relay according to the present invention.

<Explanation of symbols for main parts of the drawings>

100: RS-422 communication circuit 110: data transmission unit

120: driver 131 to 13n: 1st to n relay

141 to 14n: first to n optocouplers 150: control unit

160: decoder 170: data receiving unit

Features of the present invention for achieving the above object,

A data transmission unit for transmitting data,

A driver for outputting a transmission signal according to a signal output through the data transmission unit;

A plurality of relays connected in parallel to the output terminal of the driver,

A plurality of optocouplers connected to an output terminal of each relay and receiving a transmission signal output from the driver according to the driving of the relay;

A control unit for outputting a control signal to control the operation of each relay;

A decoder for transmitting a control signal to a corresponding relay according to the control signal output from the controller;

It characterized in that it comprises a data receiving unit for receiving a signal output through each of the opto-coupler.

Hereinafter, the configuration of the RS-422 communication circuit using the relay according to the present invention will be described in detail with reference to FIG.

2 is a block diagram showing the configuration of an RS-422 communication circuit using a relay according to the present invention.

Referring to FIG. 2, the RS-422 communication circuit 100 using the relay according to the present invention outputs a transmission signal according to a data transmitter 110 for transmitting data and a signal output through the data transmitter 110. The driver 120, a plurality of relays 131, 132,... 13n connected in parallel to the output terminal of the driver 120, and an output terminal of each of the relays 131, 132, ... 13n are connected to the relay 131, 132, ... 13n controls the operation of the plurality of optocouplers 141, 142, ... 14n and the relays 131, 132, ... 13n that receive the transmission signal output from the driver 120 in response to the driving of the 132, ... 13n. A control unit 150 for outputting a control signal, a decoder 160 for transmitting a control signal to corresponding relays 131, 132,... 13n according to a control signal output from the control unit 150, and respective optocouplers ( And a data receiving unit 170 for receiving a signal output through the signals 141, 142, ... 14n.

Hereinafter, the operation of the RS-422 communication circuit using the relay according to the present invention will be described in detail with reference to FIG. 2 as an example.

First, when the data receiving unit 110 receives data only through channels 1 and 2, the controller 150 selects a first relay 131 and a second relay 132 and selects a driving signal (Relay Select Control Signal 1, Relay). When outputting the Select Control Signal 2, the decoder 160 outputs driving signals (Relay Select Signal 1, Relay Select Signal 2) to the first relay 131 and the second relay 132 corresponding thereto.

Then, since only the first relay 131 and the second relay 132 are turned on, and the remaining relays 13n remain off, the transmission signals of the driver 120 are transmitted to the first optocoupler 140 and the second optocoupler. Only outputs to 141.

Then, since the first opto coupler 140 and the second opto coupler 141 operate, the data receiver 170 receives data through the first channel and the second channel.

Therefore, switching the relay through the decoder prevents interference between the corresponding communication channel and other adjacent channels, and simplifies the circuit by ensuring the operating current value of the optocoupler while using one driving driver.

As described above, according to the RS-422 communication circuit using the relay according to the present invention, by selectively operating the opto coupler using the relay to ensure the operating current value of the opto coupler, the signal can be delivered by ensuring the It simplifies the design, maximizes the efficiency of the circuit design, and passes the signal through only certain channels, thus preventing interference between adjacent channels.

Claims (1)

A data transmission unit for transmitting data, A driver for outputting a transmission signal according to a signal output through the data transmission unit; A plurality of relays connected in parallel to the output terminal of the driver, A plurality of optocouplers connected to an output terminal of each relay and receiving a transmission signal output from the driver according to the driving of the relay; A control unit for outputting a control signal to control the operation of each relay; A decoder for transmitting a control signal to a corresponding relay according to the control signal output from the controller; RS-422 communication circuit using a relay, characterized in that it comprises a data receiving unit for receiving a signal output through each optocoupler.