SU818019A1 - Device for testing serviceability of counters - Google Patents

Description

(54) EFFICIENCY MONITORING DEVICE

COUNTERS

The invention relates to a pulse technique and can be used in measuring instrumentation.

A device is known that contains a decoder with the number of states of the monitored counter, a trigger, elements AND and a delay element, the output of the decoder is connected to one trigger input, the other installation input is connected to the inputs of the delay element and the monitored counter, and the trigger output is connected to the input of the AND element , the second input of which is connected to the output of the delay element 1.

However, the device has limited functionality due to the need for the tested circuit to have a parallel output for communication with the decoder, which, as mentioned above, is not always available and, therefore, there is no possibility of control in this case. In addition, in order to implement the control, the counter must be free, otherwise the alternating switching of the decoder outputs to one of the trigger inputs is impossible. The latter circumstance leads to

increase control time, especially with manual switching.

It is also known to control the device, the operability of the counters, which contains the checked and reference counters, the first and second drivers, the delay element, the first and second AND elements, and the OR input, whose first input is connected to the output of the first AND 2 element.

The disadvantage of this device is the inability to control the counter being tested during its operation.

- The purpose of the invention is to ensure the possibility of a verifiable meter being checked during its operation.

The goal is achieved by the fact that the first and second shapers, the delay element, the first and second AND elements and the OR element, the first input of which is connected to the output of the first AND element, are entered into the device for monitoring the operability of the counters. the adder Tlo module two, the trigger and an additional element OR, the output of which is connected to the first input of the trigger, the inverse and direct outputs of KOTOpoFo are connected to the first inputs of the first and second elements AND, the second input of the trigger connected to the control input of the meter operability control device and the second input of the OR element, the output of which is connected to the reset input of the reference counter, the input of which is connected to the input of the meter health monitoring device, the input of the checked counter and the input of the inverter, the output of which is connected to the second input of the second element And you . the stroke and the third input of which are connected respectively to the output of the meter operability control device and the output of the summator modulo two, the inputs of which are connected to the outputs of the checked and reference meters, the additional outputs of which are connected to the inputs of the first and second drivers, respectively, the outputs of which are connected respectively the second input of the first element AND and the first input of the additional OR element, the second input of which is connected to the output of the delay element, the input of which is connected to the output first shaper.

The drawing shows a block diagram of the proposed device for dosing meter operability.

The device contains checked 1 and reference 2 counters, the first 3 and second 4 drivers, the delay element 5, the first 6 and second 7 elements AND, and the element OR 8, the first input of which is connected to the output of the first element And b, the inverter 9, an adder 10 modulo two, a trigger 11, and an additional element OR 12, the output of which is connected to the first input of the trigger 11, the inverse and direct outputs of which are connected to the first inputs of the first 6 and second 7, respectively, And the second input of the trigger 11 is connected to control input 13 of the control device of the counter and the second input of the element OR 8, the output of which is connected to the reset input of the reference-counter 2, the input of which is connected to the input 14 of the health monitoring device of the counters, the input of the checked counter 1 and the input of the inverter 9, the output of which is connected to the second input of the second element And 7, the output and the third input of which is connected respectively to the output 15 of the device for monitoring the operability of the counters and the output of the adder 10 modulo two, the inputs of which are connected to the outputs of the tested 1 and reference 2 counts. ranks, the additional outputs of which are connected to the inputs of the first 3 and second 4 drivers, respectively, whose outputs are connected respectively to the second input of the first element AND 6 and the first input of the additional element OR 12, the second input of which is connected to the output of the delay element 5, the input of which is connected to the output first shaper 3,

The device works as follows.

Checked counter 1 can be connected to the device, both during its operation in the operating equipment, and in

free state. In the latter case, there are no special difficulties, since the checked counter 1 and the reference sniperchik 2 are started in phase. The signals from their outputs after the first cycle of operation (trigger 11 by this time is in the state permitting element And 7) are summed modulo 2 by adder 10 and the discrepancy signal at its output indicates the presence of a malfunction in the counter being checked 1. The malfunction signal goes to the output 15 of the device in antiphase with respect to the input signal, which is after the inverter 9, gates for the And 7 element, i.e. element And 7, when counter 1 and 2 change their states, cannot be in working condition, which excludes generation of spurious impulses about malfunction of counter 1 during transients in the high-order bits of these circuits.

If a checked counter 1 is connected to the device at a random time inside the circuit's operation cycle, two cases are possible: counter I fails (and the malfunction signal is generated normally) and the case when it is healthy, but due to a mismatch between the beginning and the end of operation cycles false alarm of counter malfunction 1. This possible case is eliminated with the help of additional elements. According to the trigger signal, input 13 is cleared through the OR element 8 of the reset signal from the reference counter 2, which starts to work on the input signal from counter 1. If the boom 1 is inside its cycle of operation, then at its end by the former 3 through the element And 6, the counter 2 is reset,

Q, which means assignment of its operation cycle to the beginning of the operation cycle of the counter 1, the trigger 11 is in the permitting state for the element AND6. The same impulse: from the generator 3 through the delay element 5 and the OR element 12 sets the trigger 11 to the state forbidden for the AND 6 element and the state allowing the AND 7 element, and the reset of the counter 2 becomes further impossible. After this comes the usual mode of control.

If the checked counter 1 fails, the device switches to the control mode similarly by the signal from the for- m; .Romage 1 4 short pulse, at the end of the cycle pa (5th of the reference counter 2 through the element OR 12, affecting

J, the same installation care trigger 11.

Claims (2)

1. USSR author's certificate number 457179, cl. H 03 K 21/34, 1973. 2. "Questions of radio electronics, seri OT. 1971, issue. 14, p. 112, fig. 5 (prototype).