SU1368980A1 - Apparatus for checking pulse counter - Google Patents

Description

(

WITH

(

1) 4094302 / 24-21

2) 07/18/86

6) 01.23.88. Bksh. Number 3

2) L.A. Prokoshev and V.G. Nekrasov

3) 621.374.32 (088.8)

(f6) USSR Copyright Certificate 760102, cl. G 06 F 11/00, 03 K 21/34, 1978. USSR Copyright Certificate 1150754, cl. H 03 K 21/40, 1985.

(54) DEVICE FOR MONITORING THE PULSE COUNTER

(57) The invention can be used in automatic control and monitoring systems and serves to increase the completeness of the control. The device contains a single vibrator 1, a pulse generator 2, a comparison unit 3, an AND 4 element and a delay element 5. The introduction of the comparator unit 11 and the AND 12 element allows monitoring the operation for any malfunctions, including monitoring the initial state of the pulse counters, without which other checks are impossible. 1 il.

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 1368980

This invention relates to computable

technology and can be used in systems of automatic control and monitoring.

The purpose of the invention is to increase the completeness of control by introducing new design features that provide control of the initial state of the counter.

The drawing shows a block diagram of a device for monitoring pulse counters.

The device contains a one-shot 1, a pulse generator 2, the first comparison unit 3, the first element 4, the delay element 5, a controlled pulse counter 6, a starting bus 7, an output bus 8 for connecting the input of a controlled counter 6, the first group of input buses 9, for connecting the discharge outputs of a controlled pulse counter 6, input bus 10 for connecting the overflow output of a controlled counter 6, the second comparison unit 11, the second element I 12, the second group of input buses 13 Intended for connection of inverse bit calls, monitored counter counter 6.

The first output of the one-shot 1 is connected to the control input of the generator. In the initial state, the controlled pulse counter 6 is in the zero state (the circuit is set to

r to zero counter 6 is not shown). Item 4 is closed at the first input by the inhibiting (low) potential of the overflow output controlled by the counter of 6 pulses, and at the second

10 input - inhibitory potential from the output of the element 5 delay. By the input of the element I 4 in the initial state, with a high potential, it is open from the second output of the one-vibrator 1.

15 inverse discharge outputs of a counter-counter pulse 6 (hours 13 tires) to the inputs of the second comparison unit 11 are high potentials, as a result of which second

20 comparison unit 11 is open and, from its stroke, a high potential is applied to the second input of the second element I 12, opening it along this input to the first input of the second element

25 and 12, i.e. over the start bus 7, a trigger pulse is received, in the result of which one-shot triggers and a positive polarity pulse appears at its first output,

30 whose duration is regulated (by changing the time constant of the response chain). At the second output of the one-shot 1 synchronously with the impulse, at its first output it appears

2 pulses, the output of which is 35 negative polarity.

with the output bus 8 and with the input of the counter 6, the inputs of the comparison unit 3 are connected to a group of input buses 9 and with the bit outputs of the counter 6, the output of the And 4 element is connected to the first input of the one-vibrator 1, the first input of the And 4 element is connected to the input bus 10 and with the overflow output of the counter 6, the second input of the And 4 element is connected to the output of the delay element 5, the input of which is connected to the output of the comparison unit 3, the third input of the And 4 element is connected to the second output of the one-vibrator 1. The first input of the I 1 2 element is connected to the starting bus 7, the output and the second input element And 12 are connected respectively to the second input of the monostable multivibrator 1 and comparing the output of the unit 11, whose inputs are connected to the input Shin group 13 and with the inverse bit outputs of the counter 6 dnymi.

The device works as follows.

45

A positive pulse from the first in the course of the one-shot 1 is fed to the input of the generator 2 pulses. At the time of the presence of this pulse, at the 40th input of the generator 2 pulses, from the output it receives impulses to the input of the controlled counter 6 impulse

From the second output of the one-shot, a negative impulse goes to the third input of the element I, closing the element AND 4 through this input. The pulse duration of the one-shot 1 is chosen in such a way that the number of pulses emitted during its operation by the generator 2 pulse is equal to the conversion rate of the counter of 6 pulses. For binary

th K-bit of a single counter pack dol

K to on consist of 2 pulses.

gg Thus, with the correct bot of the counter of 6 pulses through the recalculation window of the pack, this counter gives an output overflow pulse to the AND 4 element.

50

In the initial state, the monitored pulse counter 6 is in the zero state (the setting circuit

the zero of counter 6 is not shown). Element And 4 is closed at the first input by the inhibitory (low) potential from the overflow output of the controlled counter 6 pulses, and at the second

input - prohibitive potential with. output element 5 delay. In the third input, the element And 4 in the initial state is opened with a high potential from the second output of the one-vibrator 1. С

inverse discharge outputs of the controlled counter 6 pulses (via bus 13) to the inputs of the second comparison unit 11 high potentials are applied, as a result of this the second

Comparison unit 11 is open and, from its output, a high potential is applied to the second input of the second element I 12, opening it along this input. At the first input of the second element

And 12, i.e. the start-up bus 7 receives a triggering impulse, as a result of which the one-shot 1 is triggered and at its first output a pulse of positive polarity appears,

the duration of which is regulated (by changing the time constant of the relaxation chain). At the second output of the one-shot 1, synchronously with the pulse, at its first output appears

 negative polarity.

A positive pulse from the first output of the one-shot 1 is fed to the input of the generator 2 pulses. At the time of the presence of this pulse at the input of the generator 2 pulses from its output, pulses arrive at the input of the controlled counter 6 pulses.

From the second output of the one-shot 1 negative pulse arrives at the third input of the element And, closing the element And 4 through this input. The pulse duration of the one-shot 1 is chosen so that the number of pulses emitted during its operation by the generator 2 pulses is equal to the conversion factor of the counter 6 pulses. For a binary, K-bit counter, the packet must consist of 2 pulses.

Thus, when the impulse counter 6 is working correctly, at the end of the recalculation of the pack, this counter generates an overflow impulse at the output, which is fed to the AND 4 element.

open it at the first entrance. In this case, the pulse counter 6 is zeroed. In advance of the () input pulse, the pulse counter 6 is set to the All units state, and the comparison unit 3 outputs a single signal from its output, which through the delay element 5 is fed to the second input of the AND 4 element With this signal, element 4 opens at the second input. The delay time of the delay element 5 is chosen so that the enabling signals at the first and second inputs of the AND 4 element act simultaneously. At the third input of element 4, the resolving potential appears from the second output of the one-vibrator 1 at the moment of time, which coincides with the removal of the enabling signal at the first output of this one-oscillator 1. Thus, by the time the overflow pulse arrives at the first input element 4, this element during the correct operation of the pulse counter 6 is open through all three inputs, as a result of which a signal appears at its output, indicating a positive test result. This signal is fed to the second input of the one-shot 1, having restarted it, which ensures the possibility of multiple testing of the controlled pulse counter 6.

Consider the operation of the device in the event of a malfunction.

If, as a result of a malfunction or a systematic malfunction, an overflow pulse at the output of the controlled pulse counter 6 was generated before filling it with control pulses from the generator 2 impulses, then the E 4 element opens to the first input, but is closed by the second and third inputs, i.e. An output signal indicating a positive result of the check by the And 4 element will not be generated.

If, as a result of any malfunction, the monitored pulse counter 6 is filled before the end of your pulse 1 by the generator 2 pulses, then the comparison unit 3 receives: the corresponding combination, and a signal goes to the second input through its delay element 5 element I 4, and from the output of the counter of 6 pulses controlled - the signal to

ten

20

25

0

five

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five

the first input of the element is And 4, but the element And 4 does not open, as it is closed at this time by the inhibit signal on its third input coming from the second output of the one-shot 1.

If after the output of the pulses by the generator 2 pulses at the output of the controlled pulse counter 6, for some reason, an overflow pulse occurs (for example, as a result of interference), then this pulse arrives at the first input of the AND 4 element, but the last rffe opens, since its second input has a inhibitory signal.

If the monitored pulse counter 6 is not reset, then due to the fact that some bits of the pulse counter 6 are in a single state, low potentials are supplied (through strip 12) from their inverse discharge outputs and the second unit 11 compares does not work, there is a low potential at its output, which closes the element I 12 at the second input. As a result, the one-shot 1 does not work and does not start the generator 2 pulses. Therefore, as long as the monitored pulse counter 6 is not reset, it cannot be checked.

The proposed device for monitoring pulse counters allows monitoring of operation for any faults, including monitoring the initial state of the pulse counters, without which other checks are impossible. In this way, the completeness of the control of the pulse counters is greatly increased and the probability of malfunction in the control equipment is reduced.

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Claims (1)

Formula of Invention I Meter control device pulses containing a one-shot, pulse generator, the first comparison unit, the first element I, the delay element, the first output of the single-vibration connected to the control input of the pulse generator, the output of which is connected to the output bus, the inputs of the first 5 reference block are connected to the first group of input buses , the output of the first element And is connected to the first input of the one-shot, the first input The first element I is connected to the input bus, the second input of the first element I is connected to the output of the delay element, the input of which is connected to the output of the first comparison unit, and the third input of the first element I is connected to the second output of the single vibrator, characterized in that, in order to increase the completeness of control . It additionally introduces a second comparison unit and a second element I, the first input of which is connected to the starting bus of the device, and the output and second input are connected respectively to the second input of the single-oscillator and to the output of the second comparison unit whose inputs are connected to the second group of input buses.