SU1358086A1 - Apparatus for bi-directional transmission of digital signals with conductive separation - Google Patents

Abstract

The invention can be used in the implementation of cable communications that provide two-way exchange of digital data in communication systems. management, data collection and processing. The purpose of the invention is to reduce the number of lines of communication and, noise immunity. The device consists of two receiving and transmitting units I and 2, each of which includes an optocoupler 4.1, an EC circuit 6.1, an output switch 3.1, an output amplifier 9.1 and a protective diode 10.1. By introducing resistors 17 and 18, and in each receiving-transmitting unit 1 and 2 of the optocoupler 5.1, RC circuit 7.1 and bidirectional switch 8.1, signals are sent bidirectionally over the two-wire communication line. This ensures complete galvanic separation of both signal and power circuits. 1 il. (I co 00 00 oo 05

Description

The invention relates to automation and can be used in the implementation of cable communications that provide two-way exchange of digital data in communication systems, management, data collection and processing.

The purpose of the invention is to reduce the number of -LINE communication by implementing bidirectional signal transmission over a two-wire communication line and improving noise immunity.

The drawing shows a block diagram of a bidirectional re-digital signal with galvanic separation.

The device consists of two identical transceiver units 1 and 2 Each unit contains output key 3.1, first and second optocouplers 4.1 and 5.1, first and second parallel circuit RC 6.1 and 7.1, bidirectional key 8.1, output amplifier 9.1, protective diode 10.1, first and the second power buses 11 and 12, the input / output bus 13.1, the control bus 14.1.

Transceiver units are connected

between two wires 15 and 16

communication lines. In addition, the device

contains first and second resistors

17 and 18 ..

The first input of the optocoupler 5.1 is connected to the first power bus 11 through a parallel KS circuit 7.1, the second input to the information output of the bi-directional key 8.1.

The first and second outputs of the optocoupler 5.1 are connected to the first and second inputs of the output switch 3.1, the outputs of which are connected respectively to the first and second wires 15 and 16 of the communication line and through the corresponding first and second resistors 17 and 18c of the first and second power buses 11 and 12, respectively . The information input / output of the bidirectional switch 8.1 is connected to the bus 13.-1 input / output of the first transceiver unit, the control input of the bidirectional switch 8.1 is connected to the bus 14.1 control of the first transceiver unit 1, and the information input of the bidirectional switch 8.1 is connected to the output of the output amplifier 9.1, the first and the second inputs of which are connected to the outputs of the optocoupler 4.1, the first input of which is connected to the cathode of the protective diode 10.1 and through the parallel EC-Circuit 6.1 with the first check

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house 1b of the communication line, and the second input - with the anode of the protective diode 10.1 and the second wire 16 of the communication line.

The device works in the following way.

DP information transfer from the input / output (bus 13.1) of block 1 to the input / output (bus 13.2) of block 2, on the bus

A 14.1 dual-directional key 81 is supplied with a signal providing connection of the bus 13.2 via the bi-directional key 8.1 to the input of the optocoupler 5.1,

and the control bus 14.2 of the bidirectional switch 8.2 of block 2 is given a signal that connects the output of amplifier 9.2 via the bidirectional switch 8.2 of block 2 to the bus 13.2. Information from the bus 13.1 through the bidirectional key 8.1, optocoupler 5.1 and the output key 3.1 of unit I enters the communication line. Unit 2 receives information from the communication line and through a parallel CS circuit; 6.2, the optocoupler 4.2 transmits information to the input of the amplifier 9.2. The signal from the output of amplifier 9.2 through the bidirectional switch 8.2 is fed to the bus 13.2

To transfer information from the input / output (bus 13.2) of block 2 to the input / output (bus 13.1) of block 1 to the bus

14.2 two-way key. 8.2 of block 2, a signal is supplied that connects the bus connection 13.2 through a bi-directional switch 8.2 of block 2 to the input of the optocoupler 5.2, and the bus 14.1 of the bi-directional CARL 8.1 of block 1 is given a signal that connects the output of amplifier 9.1 through

Q bidirectional key 8.1 of block 1 to the bus 13.1.

Information from the bus 13.2 through the bidirectional key 8.2, optocoupler 5.2 and the output key 3.2 of unit 2 enters the communication line. Block 1 takes in5

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the formation from the communication line and through the parallel CS circuit 6.1, the transducer 4.1 transmits information to the input of the amplifier 9.1. The signal from the amplifier output via the bidirectional key 8.1 is fed to the bus 13.1.

Control bus 14.1 and 14.2 provide control over the direction of information transfer from block 1 to block 2 and vice versa. Tires 13.1 and 13.2 are bidirectional. When transferring information from block 1 to block 2, bus 13.1 is the input and bus 13.2 is the output of the device; when transmitting information from block 2 to block 1, bus 13.2 becomes the input and bus 13.1 becomes the output of the device.

Bidirectional key 8 works as follows.

When a logical 1 (O) information signal arrives at its control input, it is transmitted from its input / output to the information output, and when a logical O signal (1) arrives at the control input, the signal is transmitted from its information input to the input / output.

Full galvanic separation of two transmit-receive units, both in signal and supply circuits, is due to the fact that the output switches 3.1 and 3.2 of blocks 1 and 2 are supplied only through resistors 17 and 18, therefore, both switches 3.1 and 3.2 are for power supply with only one source, and for signal circuits they are separated from the rest of the circuits by optocouplers 5.1 and 5.2. According to the signal receiving circuit, blocks 1 and 2 are separated by optocouplers 4.1 and 4.2. Thus, by organizing the power of keys 3.1 and 3.2 through resistors 17 and 18 and the introduction of optocouplers 5.1 and 5.2, complete galvanic separation of blocks 1 and 2 is achieved by performing both the functions of receiving and transmitting information.

The parallel KS circuits 6 and 7 are designed to accelerate transients in optocouplers 4 and 5, respectively. Diodes 10 serve to protect the optocouplers 4 from parasitic emissions of reverse polarity in the communication line. The increase in noise immunity is ensured by the fact that in the operation mode, when the keys 3 of both blocks (1 and 2) are turned off (open), both wires of the communication line are loaded on resistors 17 and 18, having the same nominal values, therefore, the occurrence of interference on the link Zi, which are characterized, as a rule, by in-phase induced current pulses, leads to a change in the potentials of each wire, but the potential difference between them does not change. False operation of optocouplers 4 is impossible.

VNIIPI Order 6008/56

Production.-polygraph, pre-e, Uzhgorod, st. Project, 4

Thus, due to the introduction of additional optocouplers, resistors and bidirectional switches, the proposed device allows to organize bidirectional signal transmission over a two-wire communication line, providing a complete galvanic separation of both signal circuits and power circuits.

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formula of invention

A bi-directional digital signal transmission device with galvanic separation, consisting of two transceiver units, which are connected by a communication line, each transceiver unit contains an output switch, the first parallel CS circuit, the first optocoupler, the protective diode, the output amplifier, the first and second inputs of which connected to the corresponding outputs of the first optocoupler, the first input of which is connected to the cathode of the protective diode and through the first parallel RC circuit to the first wire of the communication line, and the second input to the anode of the protective g Iodine and the second wire of the communication line, the first output of the output switch is connected to the first wire of the communication line, characterized in that, in order to reduce the number of communication lines and increase noise immunity, the first and second resistors are inserted into the device, and each transceiver unit - Bidirectional key, the second parallel KS circuit and the second optocoupler, the first input of which is connected to the first power supply bus through the second parallel NS circuit, and the second input to the information output of the bidirectional key, the first and second outputs of the second optr it is connected to the corresponding inputs of the output switch, the second output of which is connected to the second wire of the communication line, the first and second outputs of the output switch are also connected via the corresponding first and second resistors to the first and second power buses, respectively, the information input-output of the bidirectional switch is connected with the device input-output bus, the control input with the device control bus, and the information input with the output of the output amplifier /.

Irage 900 Subscription

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Claims (1)

The claims bidirectional transmission of digital signals with galvanic separation, consisting of two transceiver units that are connected by a communication line, each transceiver unit contains an output key, a first parallel RC circuit, a first optocoupler, a protective diode, an output amplifier, the first and second inputs of which connected to the corresponding outputs of the first optocoupler, the first input of which is connected to the cathode of the protective diode and through the first parallel RC circuit to the first wire of the communication line, and the second input to the ano house of the protective diode and with the second wire of the communication line, the first output of the output key is connected to the first wire of the communication line, characterized in that, in order to reduce the number of communication lines and increase noise immunity, the first and second resistors are introduced into the device, and bidirectional in each transceiver unit a key, a second parallel RC circuit and a second optocoupler, the first input of which is connected to the first power bus through the second parallel RC circuit, and the second input to the information output of the bi-directional key, the first and second outputs of the WTO the second optocoupler is connected to the corresponding inputs of the output key, the second output of which is connected to the second wire of the communication line, the first and second outputs of the output key are also connected through the corresponding first and second resistors to the first and second power buses, respectively, the information input-output of the bi-directional key is connected with the input / output bus of the device, the control input with the control bus of the device, and the information input with the output of the output amplifier /. VNIIIPI Order 6008/56 __________ Circulation 900______ Subscription Production-polygraph, pre-e, Uzhhorod, st. Project, 4