SU894681A1 - Device for detecting pulse loss - Google Patents

Description

(5A) DEVICE FOR DETECTING LOSSES PULSE

one

The invention relates to automation and computer technology and can be used to detect the loss of pulses, for example, when clock pulses are lost in digital tracking systems controlled by computers.

A device for controlling a sequence of pulses is known, which contains the first trigger, the single input of which through the OR element is connected to the output of the first element of the support, the AND element and drivers

MIRO

1. pulse duration

 The disadvantages of such a device are low speed and lack of control over the disappearance of more than one pulse.

The closest to the present invention is a device for detecting a loss of a pulse, containing a trigger element of the terminal, a quad selector and an IC D. element.

A disadvantage of the known device is the low reliability of detecting the loss of a pulse, due to the fact that a short-term output impulse of the device, formed by the duration of the triggers and element I.

({spruce of the invention is an increase in the Accuracy of detecting a loss of 10puts.

The goal is achieved by the fact that a second trigger, a NOT element, and a pulse generator connected by an input to the installation inputs of the first and second triggers and an input of the device 20 output - with the second input element And; the output of which through the element is NOT connected to the counting inputs of the second Trigger, connected

output with a counting input of the first trigger, the second output of which is connected to the output of the device ..

The drawing shows a block diagram of the device.

The device for detecting the loss of a pulse contains input 1, a generator of 2 pulses, the first 3 and second i pulsed triggers, an AND 5 element, a HE 6, an output 7.

The device works as follows with

In the event that a predetermined sequence of pulses arrives at the input 1 of the device, generator 2 generates a pulse signal with a frequency equal to the frequency of the input sequence, thus inverting the pair of input pulses. Inverted pulses from the output of the generator 2, operating in standby mode, arrive at the first input of the element. And Ss to the second input of which the permitting signal arrives from the direct output of the trigger 3. The HE element 6 inverts once again the pulse signal arriving at its input and sets it to the trigger input k of the trigger. For each period of the pulses at the input 1, negative impulses arrive at the installation input of the trigger 4 and its counting input, and the pulse at the counting input is delayed relative to the installation one for the generator 2 and elements 5 and 6. As a result, the triggers and 3 are in the state of logical unit. on the direct outputs, their counting inputs are blocked, and at the output of device 7 there is a logical zero signal, indicating that the input pulse sequence is not disturbed. In case of violation of the specified pos. in case of failure of one or several pulses, the installation pulses at the corresponding inputs of the flip-flops 3 and, are absent, the generator .2 switches from standby to self-oscillatory mode of operation and sets

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through the elements 5 and 6 high-frequency pulses to the counting input of the trigger 4. Under the conditions of the absence of signals at the installation inputs of the trigger 4 and 3

S high-frequency pulses fill the counter from flip-flops 3 and A and reset the logic unit signal from the direct output of flip-flop 3, which blocks element 5 and outputs the level of logic unit at output 7, indicating a failure in the pulse train.

The natural frequency of oscillator 2 is chosen greater than the frequency of the sequence at input 1, which increases the speed of the device. Thus, the introduction of the trigger 4, the generator 2 and the element 6 provides the possibility of issuing a signal

Claims (2)

20 about the detection of a failure in a sequence of pulses by a long potential signal, which increases the reliability of detecting the loss of pulses. Formula of the Invention A device for detecting a loss of a pulse, comprising a first trigger connected by a first output to the first input of an AND element, characterized in A second trigger is entered into it, the element is NOT. and a pulse generator connected to the input to the installation inputs of the first and second triggers and device input, output to the second input of the element I, the output of which through the element is NOT connected to the counting input of the second trigger connected by the output to the counting input of the first trigger, the second output of which is connected to device output. Sources of information taken into account in the examination 1. USSR author's certificate № ЦЦОбЗЗ, cl. G 06 F 11/00, 197. 2. USSR author's certificate number 621081, cl. G 06 F 11/00, 1978 (prototype). ,