SU920577A1 - Device for determination of distance to damage location of i/o interface channel - Google Patents

Description

The invention relates to electrical engineering and may be. used to determine the distance to a break or short circuit from the beginning of the I / O interface cable.

A device for determining the distance to the place of damage to the cable, comprising serially connected a clock generator of ¹⁰ pulses, a probe pulse generator, a one-dimensional pulse generator, a time-pulse converter, a ramp generator, integrating capacitors, a second ramp generator, an adjustable delay unit the second entrance. of which. connected to the clock

I have pulses, and other inputs with a switch, the input of which is connected to the actuator and the output of the comparator, parallel to which, 2 are connected integrating capacitors [1].

The disadvantages of the device are the low accuracy and complexity.

Closest to the proposed technical essence is a device for determining the distance to the place of damage to wires and cables using the location method, containing a probe pulse generator, a delay element, a probe pulse transmitter, the output of which is connected to the drive and through the first input of the modulator with an amplifier-expander, the output of which is connected to the first input of the switch, the first and second outputs of which are connected to series-connected capacitors and the first and the second input of the second switch, the first input of which is connected to the second input of the modulator and the output of the measuring pulse generator, the input of which is connected to

The probe pulse generator 1 generates signals arriving at the pulse expander 6. In the initial state (high level at input 5 S), trigger 11 is set to 0 state due to the low level supplied to input R from the output of the adjustable delay element 12.

With the input signal 10 from the generator 1 of the probe pulses, the RS-trigger 11 goes into a single state, the high level from the output of the RS-trigger 11 goes to the input of the element And 7 and the input of the element 12 of the adjustable delay and the capacitor 15 is charged through the diode 13 and the potentiometer 14. Upon reaching the response threshold of the adjustable delay element 12, the RS20 of the trigger 11 is reset to zero. In this case, the capacitor 15 is discharged through the potentiometer 14 and diode 13. The delay time is changed by changing the value of rotivle25 Nia potentiometer 14.

At the same time, the signal of the probe pulse generator 1 sets the trigger 9 to a single state. The delayed signal of the generator 30 of the probe pulses from the output of the delay element 2 is supplied through the transmitter 3 of the probe pulses to the communication line 5. Reflected signals from the place (damage from line 5 of the communication goes to the input of the amplifier 4 of the reflected pulses, the output of which is connected to the second input of the And 7 element. The signal from the extender 6 pulses, which is the signal response of the And 7 element, since after the place of damage the remaining part of the line is not excited by the probe signal, the duration in the pulse expander is adjusted so that the duration of the resolution signal decreases from the maximum value to d of the pulse duration of the probe pulse generator. This ensures the search for reflected signals from the damage site, starting from the end of the line. Therefore, all pulses reflected from inhomogeneities located in time between the probe and the pulse reflected from the damage site have no effect on distance measurement a comparator, the input of which is connected to the second output of the delay element, and the second output of the probe pulse generator is connected to the second inputs of the switches [2].

The disadvantages of this device are the low accuracy of measurement, the complexity of manufacturing and tuning, large dimensions.

The purpose of the invention is to improve the accuracy of measurement.

This goal is achieved by the fact that in the device containing a series-connected probe pulse generator, a delay element, a probe pulse transmitter, the output of which is connected to the communication line and the input of the reflected pulse amplifier, an indicator and a measurement unit, a pulse expander, an element And a trigger are introduced, and the output '' the probe pulse generator is connected to the first input of the trigger and the input of the pulse expander, the output of which is connected to the first input of the element And, the second input of which is connected to the output For reflected pulses, and the output with an indicator and a second trigger input, the output of which is connected to the input of the measurement unit.

In FIG. 1 shows a block diagram of a device; in FIG. 2 schematic diagram of a pulse expander; in FIG. 3 timing diagram of the device.

The device comprises a probe pulse generator 1, a delay element 2, a probe pulse transmitter 3, a reflected pulse amplifier 4, a communication line 5, a pulse expander 6, an I 7 element, an indicator 8, a trigger 9, a measurement unit 10.

The pulse expander 6 contains an RS-trigger 11, the input of which is connected to a pulse generator 1 probing it, the R input is connected to the output of the adjustable delay element 12, the output of the RS-trigger 11 is connected to the first input of the AND element 7 and the input of the adjustable delay element 12, the second input element 12 adjustable delay connected to the output of the 'RS-trig Hera through a diode 13 and a potentiometer, 14, as well as with a capacitor 15> connected to the Earth bus. '

The device operates as follows.

. 920577 6 will be. When matching the belt per **! On the other hand, from the end of the reflected pulse line with a resolution pulse in the AND element, a signal is generated that will go to the second input of the trigger and put it into state 0, and the indicator signals the presence of the first heterogeneity, which is the place of damage to the line. A further decrease in the duration of 1 signal from the pulse expander will allow fixing other inhomogeneities in the line.

The measurement unit measures the duration of the trigger pulse, 1 thereby provides a measurement of the distance to the place of damage directly in units of length. The measurement unit can be performed using a dial gauge or on 2 digital elements. In addition, the measurement of the distance to the place of damage in the communication line can be performed according to the scale of marks placed in front of the knob for adjusting the potentiometer ele-25 adjustable delay. On the scale of divisions, units of length are plotted taking into account the cable parameters. The device does not require additional configuration before starting work, small-sized, with self-powered power supply.

In FIG. 3 is a timing diagram of the device where: a probe and reflected pulses from inhomogeneities, and places povrezhde- ₃₅ Nia link; b - signal of the probe pulse generator; a - signal to trigger · g - signal pulse expander (arrow shows voltage changes when determining the duration _1c dividing the distance to the harmed of the conversation); q signal from the output of the And element, which sets the trigger to zero · state.

The device can be used in complex automated systems. management.

Claims (1)

39 by the output of a comparator, the input of which is connected to the second output of the delay element, and the second output of the generator of probe pulses is connected to the second inputs of the switches z. The disadvantages of this device are the low accuracy of measurement, the complexity of manufacturing and tuning, and the large dimensions. The purpose of the invention is to improve the measurement accuracy. This goal is achieved by the fact that a pulse expander, an And element and a trigger, are inserted into a device containing a series-connected probe pulse generator, a delay element, a probe pulse transmitter whose output is connected to the communication line and the input of a reflection amplifier amplifier, an indicator and a measuring unit. moreover, the output of the probe pulse generator is connected to the first input of the trigger and the input of the pulse expander, the output of which is connected to the first input of the element I, the second input of which is connected to the output of the force ate reflected pulses, and output - with the indicator and the second input flip-flop, whose output is connected to the input of the measurement unit. FIG. 1 shows a block diagram of the device; in fig. 2 is a schematic diagram of the pulse expander; in fig. 3 temporary diagram of the device. The device contains a generator of 1 probe pulses, a delay element 2, a transmitter of 3 probe pulses, an amplifier C of reflected pulses, a communication line 5, a pulse expander 6, element 7, an indicator 8, a trigger 9, a measurement unit 10. Pulse expander 6 contains an RS-flip-flop 11, whose input is connected to a generator of 1 probe pulses, R input is connected to the output of adjustable delay element 12, output of RS-flip-flop 11 is connected to first input of element 7 and input of adjustable delay element 12, second input of element An adjustable delay 12 is connected to the output of an RS-trigger via diode 13 and a potentiometer. H, as well as with a capacitor 15. connected to the bus Earth: The device works as follows. The generator 1 probe pulses produces signals arriving at the expander 6 pulses. In the initial state (high level at input S), the trigger 11 is set to the state due to the low level applied to the input R from the output of the adjustable delay element 12. With the input of the input signal from the oscillator 1 of the probe pulses, the RS flip-flop 11 goes into one state The high level from the output of the RS flip-flop 11 is fed to the input of the element And 7 and the input of the adjustable delay element 12 and the capacitor 15 is charged through the diode 13 and potentiometer 1. When the threshold of the adjustable delay element 12 is reached, a reset occurs RS trigger 11 is in the zero state. This causes the capacitor 15 to discharge through potentiometer 14 and diode 13. The change in the delay time is achieved by changing the resistance value of the potentiometer 1tt. At the same time, the signal of the probe pulse generator 1 sets the trigger 9 to one state. The delayed signal of the generator 1 probe pulses from the output of the element 2 delay enters through the transmitter 3 probe pulses in the communication line 5. The reflected signals from the fault site from the communication line 5 are fed to the input of the amplifier 4 reflected pulses, the output of which is connected to the second input of the element AND 7. The first input of the element 7 receives a signal from the expander 6 pulses, which is after the damage site the remaining part of the line is not excited by the probe signal, the duration adjustment in the pulse expander is made so that the duration of the resolution signal decreases from the maximum value to the duration value The pulse of the probe pulse generator. This ensures the search for reflected signals from the fault site, starting from the end of the line. Therefore, all pulses reflected from irregularities, located in time between the probe pulse and the pulse reflected from the site of damage, will not affect the distance measurement. When the first pulse from the end of the line of the reflected pulse coincides with the resolution pulse in the element I, a signal is produced that goes to the second input of the triggera and transfers it to the state O, and the indicator signals the presence of the first inhomogeneity that is line damage. A further reduction in the duration of the signal from the expander. The pulses will allow to fix other inhomogeneities in the line. The measurement unit measures the trigger pulse duration, thereby providing a measurement of the distance to the damage site directly in units of length. Measurement can be performed using a needle instrument or on digital elements. In addition, the measurement of the distance to the fault in the communication line can be performed according to the scale of divisions, applied by the knob of the potentiometer control of the adjustable delay element. On the scale of divisions, units of length are plotted taking into account the cable parameters. The device does not require additional configuration before starting work, small-sized, self-powered. FIG. 3 shows a temporary diagram of the operation of the device where: a -. probe and reflected pulses from nonuniformities and the place of damage to the communication line; b is the signal of the probe pulse generator; c is the signal on the trigger; d is the pulse extender signal (the arrow indicates the voltage change duration when determining the distance to the place of damage .9 76 days); d is the signal from the output of the AND element, setting the trigger to the zero state. The device can be used in complex automated control systems. Claims: Disposition device; Stopping to the point of damage to the I / O interface line, containing a series-connected probe pulse generator, a delay element. transmitter of probe pulses, the output of which is connected to the communication line and the input of the amplifier of reflected pulses, an indicator and a measuring unit, characterized in that, in order to improve the measurement accuracy, a pulse extender, an And element and a trigger are inserted into it, and the output of the probe pulse generator connected to the first input of the trigger and the input of the pulse expander, the output of which is connected to the first input of the element I, the second input of which is connected to the output of the amplifier of the reflected pulses, and the output to the indicator and the second input igger, the output of which is connected to the input of the measuring unit. Sources of information accepted. Attention in the examination 1. The author's certificate of the USSR № b3D + Ze, cl. G 01 R 31 / P, 19772. Author's certificate of the USSR No. 26373, cl. G 01 R 31/11, 19b9. 15  -n 12 l but one/