SU1718222A1 - Device for checking logical circuits - Google Patents

Abstract

The invention relates to automation and computer technology and can be used in the monitoring and diagnostics of control devices of industrial robots, CNC machines and others whose operation is cyclical. The aim of the invention is to expand the functionality by recording information about the current consumption. A device for monitoring logic circuits contains current sensors, a subtraction unit, an A / D converter, a comparison circuit, a counter, a random access memory block, an information block, triggers, AND, OR elements. 1 il.

Description

The invention relates to automation and computer technology and can be used in monitoring and diagnosing control devices of industrial robots, CNC machines and others whose operation is cyclical.

The purpose of the invention is to expand the functionality by recording information about the current consumption.

The drawing shows a block diagram of the proposed device.

The device contains the first 1 and second 2 current sensors, the subtraction unit 3, the analog-digital converter (ADC) 4, the comparison circuit 5, the counter 6, the operational memory block 7, the first 8, the second 9 and the third 10 And elements, the OR element 11 , the first 12 and second 13 triggers, the display unit 14, a controlled logic circuit 15. The reference logic circuit (not shown) is used in solving the problem of checking the health and is installed in the first cycle of the device operation to control the logic circuits in place of the monitored logic circuit 15.

The device works as follows.

When checking the correct functioning of the monitored logic circuit, the input to the sign of the device record, i.e. To the installation input of the trigger 12, the corresponding logic signal is supplied, which translates the trigger 12 into the unit state. In this case, element 8, one of the inputs of which receives a direct signal from the output of flip-flop 12, allows the signal to sign the end of the conversion from the output of the A / D converter 4 to the input of the recording permission of the RAM block 7, and element 9 to one of the the inputs of which receives an inverse signal from the output of the trigger 12, prohibits the passage of the signal from the output of the A / D converter 4 to the input of the element 10. After the input of the installation sign, the zero of the device converts the counter 6 and the trigger 13 to the zero state. lights

WITH

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A circuit 15, after which it is put into operation mode. The current sensor 1 and 2 measure the currents flowing in the power bus and the common bus of the logic circuit 15, and output electrical signals in analog form corresponding to the measured values. In block 3, the subtraction determines the difference between the values of the signals of the first 1 and second 2 current sensors.

The resulting difference is converted into a discrete form of the A / D converter 4. Upon completion of the conversion, the A / D converter 4 generates a conversion signal, which, through an AND 8 logic element, enters the recording resolution input of the main memory unit 1. In block 7, the specified address cells, which are determined by the code combination at the output of counter 6, the difference in current consumption of the logic circuit 15 flowing in the power bus and the common bus, are recorded for the first operation cycle.

When the monitored logic circuit arrives from the synchronization output of the second pulse, ADC 4 is restarted, digitizing the difference between the signal values of the first 1 and second 2 current sensors. Upon completion of the conversion process, block 7 writes the resulting value in binary code to the next memory location. The process of measuring the currents flowing in the power bus and the common bus of the logic circuit 15, determining their difference, digitizing and writing to the cells of the RAM unit 7 continues until the trigger 12 of the corresponding logic signal arrives at the reset input. , indicating the end of the cycle of the controlled scheme. A work cycle for an object of control, for example, for control systems of industrial robots or production equipment, is a specific sequence of control actions, which results in the equipment performing a certain technological function. At the end of the control system cycle, the next cycle begins, similar to the previous cycle.

Thus, in the first cycle of operation, which is carried out under the supervision of the operator, information is recorded about the functioning of the control object in the form of the difference in current consumption of the controlled logic circuit 15 flowing in the power bus and the common bus into the operational memory unit 7.

At the end of the first cycle of operation of the circuit 15, the trigger 12 is switched and, by applying a zero level to the input of the element 8, blocks the passage of recording resolution pulses from the output of the A / D converter 4 to the input of the RAM block 7. However, from the inverse output of the trigger 12 a single signal is fed to the input of the element And 9 and thereby allows the passage of the signal from the output of the ADC 4 to the input of the element And 10.

In the second cycle of operation of the test object, the first 1 and second 2 current sensors, block 3 subtraction, ADC 4 function the same as in the first cycle. However, the difference in consumption currents in a discrete form for each cycle of operation of circuit 15 is compared by comparison circuit 5 with the difference of currents recorded for the same cycle in the first cycle of operation. If the compared values at the output of the comparison circuit 5 coincide, the zero level, which, when the A / D converter 4 arrives through the AND 9 element at the input of the And 10 element, signals a signal that the conversion of the A / D converter 4 is complete and the signal passes the output from the comparison circuit 5 to the trigger input 13 , does not throw the last one. If the indicated values do not match, indicating a violation of the correct functioning of the control object, a single signal appears at the output of the comparison circuit 5, which switches the trigger 13. The trigger state 13 is converted into visual information in the display unit 14. The signal from the output of the trigger 13 can be used to block the further operation of the control object.

The health check of the monitored logic circuit 15 is carried out in a manner similar to the validation check. A distinctive feature of the health check is that in the first cycle of operation of the device in place of the controlled logic circuit 15, the reference logic circuit is established. Thus, in block 7, the information about the standard responses of the control object is recorded. At the end of the first cycle, the reference logic circuit is replaced with a controlled one.

The appearance of a signal at the input of the recording attribute, which enters the input of the trigger setup 12, does not correlate in any way with the frequency of the controlled logic circuit 15. This signal appears at the moment of the completion of the cycle of the circuit 15 operation.

The controlled circuit 15 has no design features. In the subtraction unit, signals proportional to the currents flowing in the power bus and the common bus of the circuit 15 are subtracted.

Synchronization tools for the subtraction unit are not provided because it is not necessary. The subtraction unit is running continuously. Synchronization with the operation of the controlled circuit 15 is achieved by using synchronizing pulses from the output of circuit 15 to start the A / D converter 4.

The sync output of circuit 15 can be used to solve problems of checking the health and checking the correctness of operation, without isolating the internal generator of circuit 15 from the composition of the monitored circuit, since the absence of generation of clock pulses in the first case will trigger the trigger 13 and indicate the malfunction, and in the second, t. e. when checking the correct functioning, it will not allow to write to the RAM unit 7 information about the first cycle of operation of the controlled circuit 15, carried out under the control of the operator.

The comparison circuit is a comparison circuit of two bit logic signals. As a comparison circuit 15, for example, the K 555 SP 1 microcircuit can be used. The comparison circuit 5 compares the signals from the outputs of the A / D converter 4 and the RAM unit 7.

Claims (1)

Invention Formula A device for monitoring logic circuits containing the first and second current sensors, a subtraction unit, an analog-to-digital converter, a comparison circuit, a reference logic circuit, a display unit, the input of the first current sensor being an input of a device for connecting a monitored logic circuit to the power supply bus. the fact that, in order to expand the functional possible by recording the current consumption information, two triggers are entered into it, three AND elements, an OR element, a RAM block, whose recording resolution, as well as a group of address inputs and a group of information inputs, are connected respectively to the output of the first AND element, bit a group of outputs of the counter, the first group of information inputs of the comparison circuit and a group of information inputs of the analog-digital converter, information input, input of the sign of the start of conversion and output of the sign of the end of conversion whose calls are connected respectively to the output of the subtraction unit, the self-synchronization output of the controlled logic circuit and the first inputs of the first and second AND elements, the second inputs of which are connected respectively to the direct and inverse outputs of the first trigger, the setup input of which is the input of the device operation mode and the reset input combined with the first input of the OR element and connected to the output of the sign of the end of the cycle of operation of the controlled logic circuit; the second input of the OR element is combined with the reset input of the second trigger and is the device zero input, the output of the element OR is connected to the blocking input of the counter, the input of the second current sensor is connected to the common bus of the controlled logic circuit, and the outputs of both current sensors with the first and second inputs of the subtractor, the output group of the operational memory They are connected to the second group of inputs of the comparison circuit, the Output Equal to which is connected to the first input of the third element AND, the second input and output of which are connected respectively to the output of the second element AND and the installation input of the second trigger, the output of which is connected to the input of the display unit. one Entry mode radat