RU2012146C1 - Device for transmitting and receiving digital signals - Google Patents

Abstract

FIELD: communications. SUBSTANCE: device has first and second optical pairs 1 and 2, two-cycle flip-flop 3, AND gate 4, univibrator 5, shift register 6. EFFECT: simplified design. 2 dwg

Description

 The invention relates to computer aids and telecommunications and can be used to organize the exchange of information in computer networks.

 A device is known for transmitting / receiving information in the form of pulses on a two-wire communication line, comprising a central unit, an information recording unit and peripheral units (see ed. St. USSR N 1185633, class N 04 L 11/10, published. 1985). The central unit controls the peripheral units and the information recording unit. All information from peripheral units is entered into the information recording unit for further use. The disadvantages of this device include the temporary separation of information, control and clock signals, which reduces the speed of the device. The transmission and reception of information are separated in time, direct exchange between peripheral units is not possible (the latter operate on the information recording unit). All this complicates the device, reduces its functionality.

 It is also known a device for receiving and transmitting information containing peripheral units that transmit information, a recording unit that receives information, a central unit that controls the reception and transmission of information over a two-wire communication line (see ed. St. CCCP N 1378076, class N 04 L 11/10, published. 1988). This device has the same disadvantages as the device according to ed. St. N 1185633, despite a slight increase in speed.

 Closest to the proposed technical solution is a device for transmitting and receiving digital signals, comprising on the transmitting side a first AND element, the output of which is connected to the first input of the OR element, the second input of which is connected to the output of the second AND element, the first input of which is connected to the output of the shift register , the third element And, the first input of which is connected to the input of the delay element, the output of which is connected to the first input of the first element And and the input of the one-shot, the output of which is connected to the second input of the second about the And element, the third input of which is connected to the second input of the third And element and with the second input of the first And element, the third input of which is connected to the output of the inverter, the input of which is connected to the output of the shift register, the synchronization input of which is connected to the output of the third And element, the first input which is the synchronizing input of the device, the control input of which is the second input of the third element And, and on the receiving side the output of the one-shot is connected to the input of the synchronizing shift register, the information input to connected to the input of a single-shot (see author St. N 1172047, CL H 04 L 5/14, published. 1985). The disadvantages of this device include the lack of alignment of the reception lines of synchronizing and control signals, as well as the lack of a write circuit for the parallel code in the shift register on the transmitting side of the device. There is also no interchangeability of the transmitting and receiving sides of the device (they differ schematically). All these disadvantages lead to a reduction in functionality and complexity of the device.

 The purpose of the invention is the expansion of functionality and simplification of the device for transmitting and receiving digital signals.

 This goal is achieved by the fact that in the known device for transmitting and receiving digital signals containing a shift register, one-shot, two-input element And, two optocouplers and a two-stroke trigger are additionally introduced, and the inputs of the first and second optocouplers are connected to the two-wire bus of the first input of the device in the opposite direction, the output of the first optocoupler is connected to the installation input of the push-pull trigger and the first input of the And element, the output of the second optocoupler is connected to the counting input of the push-pull trigger and clock input of the shift register, the output of the push-pull trigger is connected to the serial input of the shift register and the second input of the And element, the output of which is connected to the input of the one-shot, the output of the latter is connected to the input of the shift register mode selection, the output of which is the output of the device, and the parallel input of the shift register information is the second input of the device.

 By adding two optocouplers to the device for transmitting and receiving digital signals, the inputs of which are switched in the opposite direction at the first input of the device, and a push-pull trigger, it allows to reduce the total number of blocks (elements) used in this device, to increase the functionality of the device in terms of organizing simultaneous transmission and receiving digital signals in a serial code. The device also allows you to organize the recording of information in parallel code of the proposed device.

 In FIG. 1 shows a block diagram; in FIG. 2 - time diagrams of the operation of the device.

 The device contains a two-wire bus of the first input Bx1. The inputs of the two optocouplers 1 and 2 are connected to the two-wire bus of the first input Bx1 in the opposite direction. The output of the first optocoupler 1 is connected to the installation input of the push-pull trigger 3 and the first input of the element And 4, the output of which is connected to the input of the one-shot 5, the output of the second optocouple 2 is connected to the counting input of the push-pull trigger 3 and the clock input of the shift register 6. The output of the push-pull trigger 3 is connected to the sequential input of the shift register 6 and the second input of the element And 4. The output of the one-shot 5 is connected to the input of the shift register 6 mode selection, the input information recording buses in the parallel code of which are simultaneously the second input th In2 device. The output of the shift register 6 is simultaneously the output of the Output device.

 The device operates as follows.

 In the logical 1 recording mode and the shift to input Bx1, a positive current pulse (point A) is applied in the first clock cycle, from which the first optocoupler 1 is triggered along the rising edge, and a positive pulse of the same duration as the current pulse (point H). The second optocoupler 2 in this case is in the closed state. The trailing edge of a positive pulse (point H) sets the push-pull trigger 3 to a single state (point K). In the next clock cycle, a negative current pulse (point A) is applied to input Bx1, which causes a positive pulse to appear at the same duration as input Bx1 (point F). On the leading edge of the pulse, the logical "1" from the output of the push-pull trigger 3 is entered through sequential input into the first bit of shift register 6, at the same time the digital word is shifted one bit to the right. At the output of the output register (device), the penultimate discharge information appears for transferring it to the communication line. On the trailing edge of the pulse (point F), the push-pull trigger 3 is reset to the logical "0" (point K). In this case, the first mode ends, that is, the logical “1” is recorded and the digital word is shifted by one bit in two cycles.

 In the recording mode of the logical "0" and a shift, a negative current pulse (point A) is supplied to input Bx1. The second optocoupler 2 is triggered (the first optocoupler 1 is in this case closed) and a positive pulse (point F) of the same duration appears at its output. The state of the logical "0" at the output of the push-pull trigger 3 does not change. On the leading edge of the positive impulse, the logical “0” is simultaneously entered into the first digit of shift register 6 and the digital word is shifted one digit to the right. At the output of the register (device) Output, information of the last digit appears for transmission to the communication line. The second mode ends here, that is, the logical “0” is recorded and the digital word is shifted one digit to the right in one clock cycle.

 The parallel code is written to shift register 6 by applying a positive current pulse to input Bx1 (point A) in the first clock cycle. The first optocoupler 1 is triggered and a positive pulse is generated at its output (point H). The second optocoupler 2 is in this case in a closed state. At a given edge of this pulse, push-pull trigger 3 is set to a single state (point H), opening element And 4 at the second input of the latter. In the second cycle, a second positive current pulse is applied to input Bx1 (point A). Again, the first optocoupler 1 is triggered, generating a positive pulse of the same duration (point H). This pulse, without changing the state of the push-pull trigger 3, through the first input of the element 4 is fed to the input of the single-shot 5 at the leading edge starts it (point M). The pulse from the single-vibrator 5 is fed to the input of the vibrator of the shift register mode 6. The duration of the pulse generated by the single-vibrator 5 should be greater than the duration of one cycle and less than the duration of two cycles of the device. In the third cycle, a negative current pulse (point A) is supplied to input Bx1. The second optocoupler 2 is triggered, generating a positive pulse (point F). On the rising edge of the latter, information is written in parallel code from the second input Bx2 to shift register 6, and on the falling edge, the push-pull trigger 3 is reset to the zero state (logical "0"). In the third step, one-shot 5 also finishes its work (it is set again to standby mode). On this, the process of recording information in parallel code in the device ends in three clock cycles of the latter.

 As optocouplers, K262KN1 optoelectronic switches or K 24 EKN1 optoelectronic switches can be used. As a push-pull trigger, you can use the universal multipurpose IK-trigger K 155TV! , and as a shift register - a universal eight-shot shift register K 155IR13.

 Due to the use of two optocouplers, the inputs of which are switched in the opposite direction at the first input of the device, and a push-pull trigger, information and control signals can be transmitted via a two-wire communication line, which reduces the number of wires of the communication line.

The device also allows you to perform the following operations:
- simultaneously receiving and transmitting information in a serial code (first and second mode of operation of the device);
- transmission of information in a serial code (the second mode of operation of the device), in this case, in the bits of the shift register, starting from the first, a logical "0" is entered;
- write parallel code to the device (third mode of operation).

 All this extends the functionality of the device. In addition, the total number of used blocks (elements) is reduced in comparison with the prototype, which simplifies the circuit of the device. The use of optocouplers performing galvanic isolation of the first input of the device and the two-wire line increases the noise immunity.

 The expansion of functionality leads to the expansion of the scope of this device in systems of transmission and reception of information using computers.

Claims (1)

 DEVICE FOR TRANSMITTING AND RECEIVING DIGITAL SIGNALS, containing a shift register, one-shot, element And, characterized in that, in order to expand the functionality by both separate and simultaneous reception and transmission of information in serial and parallel codes, two optocouplers and a push-pull trigger are introduced moreover, the inputs of the first and second optocouplers are connected to the two-wire bus of the first input of the device in the opposite direction, the output of the first optocouple is connected to the installation input of the push-pull trigger pa and the first input of the And element, the output of the second optocoupler is connected to the counting input of the push-pull trigger and to the clock input of the shift register, the output of the push-pull trigger is connected to the serial input of the shift register and the second input of the And element, the output of which is connected to the input of the one-shot, the output of which is connected to the input selecting the shift register mode, the output of which is the output of the device, and the parallel input of the shift register information is the second input of the device.

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