SU1406802A1 - Transceiver for local networks with electric and optical communication lines - Google Patents

Abstract

The invention relates to a data transmission technique. The purpose of the invention is to increase the reliability of work. The transceiver contains an exclusion unit 1 of the constant component, a band-pass filter 4, voltage converters 5 and 6 — current, resistor 9 and 10, capacitors 11. and 13, and resistors 12 and 14 of the CS chain, differential amplifier 15, peak detector 17 , the input bus 2 of the transmitted signals, the input bus 3 of the transmission blocking, the transceiver bus 7, the earth bus 8, the output bus 16 of the received signals, the output bus 18 of the receive indication and the source of the reference voltage. The device ensures error-free reception of information from another transceiver under its own transmission conditions (duplex), i.e. provides simultaneous reception and transmission of data. The goal is achieved by providing isolation between transmission and reception with the help of the introduced exception block 1, filter 4, converters 5 and 6, resistor 10, detector 17 and RC chains. 2 Il. (L

Description

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The invention relates to data transmission technology i and can be used in local information networks using electrical and optical communication lines.

The purpose of the invention is to improve the reliability of the transceiver by providing an isolation between transmission and reception. ,

Figure 1 is an electrical block diagram of a transceiver; figure 2 - timing charts of his work.

The transceiver for local networks with electrical and optical lines of communication contains a block 1 excluding a constant component, input bus 2 transmitted signals, input bus 3 transfer locking, band-pass filter 4, first 5 and second 6 voltage converters — current, bus 7 transceivers and a transceiver ground bus 8, the first 9 and second 10 load resistors, the first RC circuit including a capacitor 1 1 and a resistor 12, a second RC chain containing a capacitor 13 and a resistor 14, a differential amplifier 15, the output bus 16 taking proxy signals, peak detector 17, output line 18 indicating the source and receiving the reference voltage E.

The transceiver (Fig. 1) for local networks with electrical and optical communication lines operates as follows.

To switch to the transfer mode (FIG. 2), data is transmitted to the input bus 2 of the transmitted signals in the form of, for example, a Manchester code (FIG. 2a) 5, and an enable signal (FIG. 25) is fed to the input transmission lock bus 3, for example 1. After that, at the output of the DC block 1, data appears in the form of an alternating voltage, and if block 1 is made, for example, non-inverting, then state 1 on the input bus 2 is transmitted

corresponds to a positive voltage at the output of block 1, and to state O - a negative voltage. Band-pass filter 4 limits the spectrum of the transmitted signal.

Voltage converters 5 and 6 - current is generated by an alternating current, the shape of which repeats the shape of the voltage at the output of the bandpass filter 4.

Since the 5formant 5 and 6 are chosen the same and loaded on the same load (taking into account the communication line connected to the transfer-reception bus 7), two voltage variables coinciding in their shape and phase are formed at their outputs (resistors 9 and 10). figs, 2b, 2). The signs of these voltages correspond to the state on the output bus 2 of the transmitted signals; 1 corresponds to a positive voltage, and a negative one with respect to a constant voltage before the start of Deredach. Thus, a fundamental coincidence of the signals at the inputs of the differential amplifier 15 is ensured,

The alternating voltage from the output of the first converter 5 is voltage, the current is supplied to the bus 7 of the transmission and further to other subscribers.

In addition, the same alternating voltage / voltage from the outputs of the converters 5 and 6, the current flows through the same capacitors 13 and 11 of the first and second RC circuits to the inputs of the differential amplifier 15. However, for it they are an in-phase signal, therefore at the output of this amplifier 15 alternating voltage does not occur. Also, a low voltage at the output of the peak detector 17 is retained, less than the reference voltage - xeny E ;. Due to the difference in voltage at the inputs of the differential amplifier 15, there is a high level (1) j at its output, and the sensitivity and gain are small.

Consequently, in the transmission mode, information is transmitted from the input bus 2 of the transmitted signals to the reception-transmission bus 7 and further to other network subscribers (other transceivers) in the complete absence of interference on the reception KaHcUiy (FIG. 2, e).

In the receive mode (Fig. 2), there is no transmission, therefore, voltage converters 5 and 6 - current form a direct current. Let at some time point the data from the other subscriber (FIG. 2G) begin to arrive on the reception-transmission bus 7, the analogous transceiver of which is in the transmission mode. Then this alternating voltage from the bus 7 goes through the capacitor 11 to the first differential input. amplifier 15. Since the alternating voltage is missing at its second input (Fig.2), the output difference is 31406802

A secondary amplifier 15 (output bus 16 of the signal being printed) appears alternating voltage (FIG. 2 and) - data sent by another subscriber. This alternating voltage is detected by the peak detector 17, and on the output bus 18 of the receive indication the voltage (Fig. 2k.) Increases (becomes equal to the reference voltage E). 0, however, the electric and optical leads through the resistor 14 to the second input. communication lines containing a differential transceiver under its own transmission conditions (duplex), i.e. provides simultaneous reception and transmission of data.

Claims (1)

Claims of the Invention A transceiver for local networks with electrical and optical communication lines, comprising a differential transceiver under its own transmission conditions (duplex communication), i.e. provides simultaneous reception and transmission of data. Invention Transceiver for local networks differential amplifier 15. The DC voltages at the inputs of this amplifier become almost equal, and its sensitivity, and the gain, is maximum. After termination of data reception, the transceiver returns to its original state. In the mode of simultaneous reception and transmission (FIG. 2), the transceiver nodes operate in the same way as described. The diagram in Fig. 2 shows an alternating voltage across the resistor 9, which is formed due to the alternating current from the output of the first voltage converter 5 - the current during the transmission of data supplied to the input bus 2 of the transmitted signals. The diagram in FIG. 2m shows the alternating voltage applied to bus 7 via an electrical communication link from another transmitting transceiver. As a result, the sum of both alternating voltages (fig.2n) is formed on the first load resistor 9, and only the transmitted alternating voltage is generated on the second load resistor 10. Summation is possible because the current of the converter 5 (6) voltage - the current depends only on the transmitted data, but does not depend on the voltage on the bus 7 reception-transmission. Differential amplifier 15 selects the received signal from its sum with the transmitted signal (fig.2o) due to the presence of the transmitted signal at the other sample input. Therefore, the proposed device provides error-free reception of information from another gg A main amplifier and a first load resistor, characterized in that, in order to increase the reliability of operation by providing a junction between transmission and reception, a second load resistor, the first and second RC circuits, the first and second voltage converters - current, are introduced into it a detector, a bandpass filter, and a dc exclusion unit, the first input of which is connected to the input bus of the transmitted signals, a second input connected to the input bus of the transmission block, the output of the dc block through the polo The common filter is connected to the inputs of the first and second voltage converters — the current; the output of the first voltage converter — the current is connected to the receive / transmit bus directly, through the first load resistor to the earth bus of the transceiver, and through the capacitor of the first RC chain is connected to the first input a differential amplifier connected through a resistor of the first RC chain to a reference voltage source, the output of the second converter is the current through the second load resistor connected to the ground bus of the transceiver , and through the capacitor of the second RC circuit, to the second input of the differential amplifier, the output of which is connected to the output bus of the received signals and through a peak detector to the output bus of the reception indication connected through the resistor of the second RC chain to the second input of the differential " and U-LJ-L FIG. 2