SU760102A1 - Pulse counter monitoring device - Google Patents

Description

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A device for monitoring pulse counters is related to computing and can be used in automatic control and monitoring systems.

A device for monitoring pulse counters is known [Ts. ^five

The known device is difficult and not sufficiently reliable as for controlling the low-order digits of the monitored counter an additional control small-bit counter is used. Therefore, when signaling a malfunction that occurred, there is no exact information about which of the meters failed. The device also does not control the failure of each of the ₍₅ high-order bits. So, if one of the high-order digits of the controlled counter fails, due to the appearance of transfer signals from the outputs of previous High-order digits that coincide in time with the signal of the control counter transfer signal expander discharges) and, accordingly, signals will appear on the output bus of the control signal output, which

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indicate the correct functioning of the counter.

The closest technical solution to the invented unit is a device for controlling pulse counters, containing a single vibrator connected to the generator input of an external-start pulse train, to the input of the And element and to the control counter input, the outputs of which are connected to the inputs of the code comparison circuit, the other inputs of which are connected to the outputs of the higher digits of the counter being checked. The low-order outputs of the checked counter are connected to a multi-input coincidence circuit, the output of which is connected to the second input of the And element, the third input of which is connected to the output of the code comparison circuit, and the output of the single-input input to the logic unit. The output of the pulse generator is connected to the input of the counter being checked [2].

The disadvantages of the known devices are:

- the complexity of the device, and therefore not enough high reliability, due to the presence of additional control. ~

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a pulse counter and a complex multi-bit code comparison circuit of two counters;

- not enough high reliability of control due to the presence of an additional control counter. Therefore, when signaling a malfunction that occurred, there is no exact information which of the counters failed;

- relatively low speed, counter checks, due to the fact that the number of pulses in a pack is equal to the coefficient of conversion of only the lower bits of the counter. Therefore, to check the operation of all digits of the counter, it is necessary to carry out repeated repeated launches of the one-shot. In this case, each restart of the one-shot should be done after a certain period of time necessary to establish the circuit of the one-shot one-shot.

, The intended purpose of the invention yavlyaet- ₂ θ Xia simplification and improvement of reliability of the control.

This goal is achieved. In the device for controlling pulse counters containing a one-shot, a pulse generator, ₂₅ comparison unit, the first element I, the delay element and the driver of the control signal, the first input of the one-vibration is the control input of the device, the output of the one-vibration is connected to the control input θ ₃ pulse generator, whose output is connected to the input of the controlled pulse counter, the first and second outputs of which are connected respectively to the input _ comparison unit and to the input element cient delay, the output of which co ₃₅ unified with the first input of the first AND gate, the comparator output is connected to the second input of the first AND gate, the output of which is connected to the second input of monostable flip-flop and a second introduced AND gate, the output of the delay θ ₄ zle- ment connected to the first input of the second aND gate, whose output is connected to a single input of the flip-flop, the first and second outputs of the control signal generator is connected respectively to a second secondary input ₄₅ of aND cerned, the third input of the first aND gate, the output odnovibrat ra is connected to the zero input of the flip-flop, whose output ^u; one with the fourth input of the first element And, the output of the pulse generator is connected to the input of the driver control signal. ⁵⁰

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

The device contains a one-shot / generator 2 pulses, block 3 comparison, the second and first elements And 4, 5, trigger 6, element,

7 delay, the driver 8 of the control signal. The output of the one-shot 1 is connected to the input of the generator 2 pulses and to zero

¹ trigger input 6. The output of the generator 2 pulses connected to the input of the controlled pulse counter 9 pulses and to the input of the shaper 8, the first output of which is connected to the first input of the first element And 5. The second input of the element 5 is connected to the output of the delay element 7 and the first input of the second element 4. The input of the delay element 7 is connected to the overflow output of the controlled counter 9, the bit outputs of which are connected to the inputs of the multi-input comparison unit 3, the output of which is connected to the second input of the element 4. The third input of the element 4 and 4 It is connected to the second output of the imaging unit 8, and the fourth input is connected to the output of the trigger 6, the single input of which is connected to the output of the element And 5. The output of the element And 4 is connected to the output of the device and to the second input of the one-vibrator 1, the first input of which is the control input of the device.

The device works as follows.

In the initial state controlled

counter 9 and trigger 6 are in the zero state. Element And 4 is closed on the first input prohibiting, (low) potential from the output of the element 7 delay and open on other inputs. Element And 5 is closed at the first input low potential, coming from the first output of the driver 8 of the control signal. Shaper 8 is a circuit that converts a series (pack) of pulses into a rectangular pulse. In the absence of a series of pulses at the input of the shaper 8 at its first output, there is a low (inhibiting) potential, and at the second output - a high (enabling) potential.

For the duration of the pulse series at the input of the shaper 8, its first output will have a high potential, and the second output will have a low potential. Element And 5 is also closed at the second input low potential from the output of the element 7 delay.

When a one-shot is started by a signal present at the first control input of the device, a single-shot start pulse appears at the output of the pulse generator 2 and at the zero input of trigger 6, confirming its zero state. At the output of the generator 2, a sequence of pulses appears at the input of the controlled counter 9 and the input of the driver 8.

In this case, a high potential appears at the first output of the shaper 8, opening element I 5 at the first input, and low potential at the second output element AND 4.

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In the case of a binary counter, this number is chosen from the condition N = 2, where k is the number of digits in the counter. Consequently, when the monitored counter 9 is working correctly, after recalculation of the pulse packet, the counter will overflow, and the discharges of the counter will be set to the zero state. At the same time, the output signal of the comparison unit 3 will open element 4 on the second input. The overflow impulse of the controlled counter 9 through the delay element 7 arrives 10 at the second input of the element 5, closed at the first input by the low potential of the first output of the driver 8, and at the first input of the element i 4, open to other entrances.

During the delay t the _rear element 7 of the delay, 5 is chosen equal to or slightly longer than the time of occurrence of a high potential at the second output of the driver 8 after the end of the burst. The output pulse of the element And 4 signals about the correct operation of the controlled counter 9 and is fed to the input of the one-shot 1, carrying out his repeated. launch. Thus, it is possible to check the monitored counter multiple times. Through various malfunctions of the counter-25 of the rolling counter 9, the element I 4 remains closed and the signal at its output does not appear. So, if the malfunction of the controlled counter 9 is connected! with the absence of an overflow pulse at its output (for example, a failure of one or several discharges), then element 4 remains closed at the first input. In case of malfunctioning of the controlled counter 9, leading to the premature appearance of an overflow pulse (for example, malfunction, etc.), the And 4 element also remains closed. In this case, the overflow pulse arrives at the second input of the element AND 5, opened at the first input by the high potential of the first output of the shaper 8. The output impulse of the element AND 5 40 enters the single input of the trigger 6, the leading edge of the impulse trigger 6 is set to ”1”. At the output of the trigger 6, a low potential appears, covering the fourth input element I 4, which is also closed for the time 45 of the burst on the third input low potential of the second output of the driver 8. Thus, the device monitors the operation of the counter 9 for any malfunctions. 50

The design features of the proposed technical solution allow: to simplify

device, and, consequently, to increase its reliability due to the implementation of the control of the work of the checked counter without an additional control counter and a complex multi-bit comparison circuit of the codes of two counters; increase the reliability of control by excluding from the analysis circuit an additional control counter, the possible malfunctions of which can lead to an incorrect assessment of the work of the counter being checked.

Claims (1)

Claim A device for controlling pulse counters, containing a one-shot, a pulse generator, a comparison unit, the first element I, a delay element and a control signal generator, the first input of the one-vibration is the control input of the device, the output of the one-vibration is connected to the control input of the pulse generator, the output of which is connected to the input of the controlled pulse pulse counter, the first and second outputs of the controlled counter are connected respectively to the input of the comparison unit and to the input of the delay element, the output of which connected to the first input of the first AND gate, the output Cf. block neniya coupled to a second input of the first AND gate whose output is connected to the second input of the monostable multivibrator, wherein | that, in order to simplify and increase the reliability of the control, a trigger and a second element I are entered into the device, and the output of the delay element is connected to the first input of the second element I, the output of which is connected to the single input of the trigger, the first and second outputs of the driver of the control signal are respectively connected to the second input the second element And, with the third input of the first element And, the output of the one-shot is connected to the zero input of the trigger, the output of which is connected to the fourth input of the first element And, the output of the pulse generator Not with the input driver control signal.