SU741268A2 - Counter testing device - Google Patents

Description

(54) DEVICE FOR CONTROLLING COUNTERS

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The invention relates to digital automation and instrumentation technology and can be used in testing binary, binary-decimal, and tacho counters and counters in other coding systems, both summing (subtracting) and reversible.

A device for controlling tO counters is known, which contains a clock generator, the output of which is connected to the input of an AND element, n controlled counters connected in series through OR elements, a 15 level distributor, (n + 1) display elements, an OR-NOT element, a trigger, and n decoders the initial state and maximum filling of the counters and n additional OR elements, while the 2d input of the device is connected to the inputs by resetting the monitored counters and the level distributor and through a trigger, the And and levels aspredelitel 25 is connected to the control inputs of controlled reversovm counters, the outputs of which are connected to the inputs of respective decoders initial state and a maximum padding 30 outputs Ko

topbix through additional elements OR connected to the inputs of the display elements and through the element OR NOT, the element AND and the level distributor - to the inputs of the elements OR, the control inputs of the decoders of the initial state and maximum filling, to the trigger input and input (n + 1) element of indication.

The known device has a lack of reliability control. So, for example, in the case of monitoring the transfer of a pulse through all the controllers in the event of a fault in one of them, it is considered that the counter that corresponds to the first non-activated display element located to the left of the included ones is defective. It is assumed that the counter is faulty because there is no transfer pulse at its output and for this reason the subsequent counter has not been established in the required state. However, there may be a case when, due to a failure in a subsequent counter, the transfer pulse through this counter does not pass, and the display element corresponding to this counter indicates that it is working properly.

. As can be seen from the above, due to the absence of the transfer pulse fixation element, a situation arises in which it is difficult to make a reliable decision: either there is really no transfer pulse at the output of the counter and this counter should be considered defective, or due to a failure in the subsequent counter impulse transfer through it is not successful and a subsequent counter should be considered as faulty.

The aim of the invention is to increase the reliability of the control.

The goal is achieved by the fact that a meter control device containing a clock generator, the output of which is connected to the input of the element AND, n controlled meters, connected in series through the elements OR, the level distributor, (n + 1) display elements, the element OR NOT, the trigger, initialization and maximization of the counters and n additional elements OR, while the device input is connected to the inputs by resetting the monitored counters and the level distributor and Erez trigger AND gate valve and connected to the inputs of level control reverser controlled counters, the outputs of which are connected to the inputs of respective decoders initial state and maximum fill their outputs through OR additional elements. connected to the inputs of the display elements and through the element OR NOT, the element AND and the level distributor - to the inputs of the elements OR, the control inputs of the decoders of the initial state and maximum filling, to the trigger input and the input (n + 1) of the display element, entered (nl } triggers of fixation of transfer pulses and a group consisting of (nl) AND elements, the output of each k-th element of the AND group is connected to the third input (Kl) -ro of the additional OR element, the output of the additional element OR is connected to the first input of the -th element AND groups, exit to the trigger of the transfer pulse fixation is connected to the second input of the k-th element AND group, the installation inputs of the transfer pulse fixation triggers are connected to the device input, the output of the level distributor is connected to the zero input transfer trigger triggers, the single input of the transfer pulse fixation trigger is connected to the pulse transfer of the kth counter.

The block diagram of the meter control device is shown in the drawing.

The device contains a clock generator 1, the element And 2, RS-trigger 3,

distributor 4 levels, element OR 5, additional elements OR b (controlled) counters 7, decoders 8 of the initial state of the counters decoders 9 of the maximum filling of the counters, display element 10, element OR NOT 11, trigger pulses 12, pulse group I 13 .

The device works as follows.

On switching on the device, the Start pulse is set to the initial zero state of the distributor of 4 levels and controlled counters 7. The initial single state sets the transfer pulse latching trigger 12, covering the two-way elements E 13 and the RS flip-flop 3, allowing the receipt of pulses of the clock generator 1 through element 2 to the input of the distributor 4. If the monitored counters 7 are reversible, the output of the control of the reverse of the distributor 4 establishes the level of addition, and the output of the poll of the decoder 8 is the run state is set to a single poll level. If one of the monitored counters 7 is not reset, then a single level is formed at the output of the corresponding decoder 8 of the initial state, which through the OR element, 6 turns on the corresponding indication element 10 and through the element OR-HE 11 and the AND element 2 prohibits . The arrival of pulses from the clock generator 1 at the input of the distributor 4. At the same time, the polling level of the decoders 8 at the output of the distributor 4 is fixed, which is accompanied by the constant switching on of the display element 10. If all the monitored counters 7 have been reset, as evidenced by the zero level at the outputs of the decoders 8, the next monitoring stage begins.

Through parallel-connected inputs of elements 5 in parallel to all counters, 7, i count pulses are fed to completely fill the monitored counters 7, where 1 for the binary counter is determined from the ratio

i 2 - 1, where n is the counter size; for

binary counter

i 1, where ha is the number of tetrads in the counter.

After all the monitored counters 7 are filled, the decoder 9 is polled with a single level from the output of the distributor 4. In this case, if any of the monitored counters 7 fail, a single level is generated at the output of the corresponding decoder 9 b turns on the display element 10 and closes the element 2 through element 11, and the polling level of the decoder 9 is fixed at the output of the distributor 4. If the counters 7 are working, the next monitoring step is performed. Thus, the monitoring of the operability of the counters in the modes described above is carried out as in a known device. At the beginning of the next stage of monitoring the counters from the output of the distributor 4, one counting pulse is applied to the input of the first element OR 5, which sets the transfer pulse latching trigger 12, the opening elements AND 13 to the zero state, and must sequentially switch the controlled counters 7 to the initial state. Moreover, if the transfer pulse is present at the output of the controlled counter 7, it remembers with the corresponding trigger 12 of the transfer pulse fixation. In the case of the absence of a transfer pulse at the output of the controlled counter 7, the corresponding trigger 12 of the transfer pulse fixation will remain in the zero state, maintaining the corresponding AND 13 element in the open state. To illustrate the operation of the device at this monitoring stage, it is advisable to consider possible faults that can arise in the process of controlling counters. Suppose that the jth supervised counter 7 is faulty and there is no transfer pulse on its course. Consequently, the subsequent j + l, ..., n controlled counters 7 are not reset. When interrogating the decoders 8 with the unit level from the distributor 4, the unit level coming through the corresponding additional element OR b to the display elements 10 will be set at their outputs corresponding to the monitored counters 7 that are not initialized to the initial state. Since at the output of the j-ro controlled counter 7 there was no transfer pulse, the corresponding trigger 12 of the transfer pulse fixation remained in the zero state. Therefore, a single level from the output of the decoder 8, corresponding to J + 1 controlled counter 7, through an open two-input element And 13 enters the input of an additional element OR b, corresponding to the j-th controlled counter 7. At the same time, the polling level of the decoders 8 at the output of the distributor 4 fixed, which is accompanied by the constant inclusion of the display elements 10. In this case, the jth controlled counter 7, corresponding to the first / 1th element 10 of the display, should be considered faulty. Now suppose that at the output of the j-ro controlled counter 7, the transfer momentum was present, which was fixed by the corresponding trigger 12 of the transfer pulse fixation, and J + 1 controlled counter 7 tie was reset to its original state due to its own fault. Consequently, J + 2, j + 3, ..., n monitored counters 7 are also not set up, c to their initial state. When polling the decoders 8 with a unit level from the distributor 4, - at the outputs of the decoders corresponding to the faulty j + i, J + 2, j + 3, ..., n controlled counters 7, the unit level will be set. Since the transfer pulse at the output j-ro of the controlled counter 7 was present, the corresponding trigger 12 of the transfer pulse fixation was set to one and thus prohibited the passage of the decoder 8 corresponding to j + 1 to the failed monitored counter 7 passing through the And 13 element to the unit level p of the output of the decoder 8. Therefore, a single level from the output of these decoders 8 through the corresponding additional elements OR b includes elements 10 of the display. In this case, it is necessary to consider faulty j + 1 controllable counter 7, corresponding to the first activated element 10 of the display. If the ree monitored counters 7 are reset, the next monitoring step is performed. At the output of the distributor 4, a subtraction level is set. From the pulse output of the distributor 4 to the inputs of the installation in the zero state of the triggering triggers 12, the transfer pulses receive a pulse that sets them to the zero state. In addition, this pulse through the first element OR 5 is successively fed to all monitored counters 7, after which the number 1 is recorded in them. At the output of the distributor 4. a polling level of the decoders 9 is formed. At the same time, if the transfer pulses during the reverse have not passed, the device It works according to the algorithm described at the previous control stage, and the triggering of the 12 fixation of transfer pulses makes it possible to unambiguously identify the faulty monitored counter 7. If the control stage described above has passed, the device goes um to the next control step. Through the elements of OR 5, i counts are applied to the counting inputs of all monitored counters 7 of the PM1, and the counters 7 must return to the initial state. The polling level from the distributor 4 polls the decoders 8 of the initial state. Since the check of the controlled counters 7 at the previous stage was successful, all the triggering triggers 12 for the transfer pulses remained in the single state and all the two-input elements And 13 were closed. If the monitored counters 7 are faulty, the device operates according to the algorithm described above.

In the case of the normal operation of all monitored counters, after the last control stage, a level is formed at the output of the distributor 4, which turns on the element 10 of the general availability indication and turns off the trigger 3.

It can be seen from the above that the use of new elements (p-1) of transfer pulse fixation triggers and p-1 elements allows to obtain a new set of features that favorably distinguish the proposed device for controlling counters from the prototype, since it significantly increases the reliability of the control and eliminates ambiguity determining a faulty meter.

Claims (1)

Claims of the Invention Device for controlling “meters” by aut. St. 518774, characterized in that, in order to increase the reliability of the control, (p-1) triggering pulses for the transfer pulses and a group of (p-1) AND elements are entered into it, the output of each kth AND element of the group is connected to the third input (K +1) -th additional element OR, the output of the k-th additional element OR is connected to the first input of the k-th element of the AND group, the output of the k-th trigger of the transfer pulse fixation is connected to the second input of the k-th element of the AND group, the installation inputs of the latching trigger transfer pulses are connected to the input of the device, the output is divider is connected to the zero level input transfer pulses fixation triggers, a single input to the second transfer pulses trigger lock connected to the transfer pulse to the second counter.