SU864545A1 - Device for testing operability of analogue-digital converter - Google Patents

Description

(54) DEVICE FOR MONITORING THE OPERATION CAPACITY OF ANALOG-DIGITAL CONVERTERS

one

The invention relates to computing and automation and can be used to monitor the performance of single-channel or. multichannel analog-digital converters in the production process of equipment for automatic control systems during adjustment and acceptance tests.

A device for testing analog-to-digital voltage-code converters is known, which uses the automatic mode of checking and sorting devices using the method of sequential static analysis. The device contains a verifiable converter, a code converter, a digital subtraction unit, a code setter, a source of model controlled voltage, a code comparison unit, counters, indicators, discriminators, a setpoint of error probabilities, digital-analogue converters.

A disadvantage of the known device is that it stops the operation of the tested converter when fixing the defect, which complicates the analysis and troubleshooting during adjustment operations, complicates their calibration, and the absence of the device self-test mode reduces the reliability of its operation and can lead to skipping precision converters.

The drawback of the device is also the possibility of operator errors during visual inspection, the impossibility of analyzing the accuracy of the output characteristics of the converters under test due to the lack of documentation of the conversion results, the inability to accurately determine the error value of the ADC

15 at any point on the conversion scale and the lack of control over the timing of the output signals.

The purpose of the invention is to expand the functionality of the device.

The goal is achieved by

20 that in the device for monitoring the performance of analog-to-digital converters, containing a synchronization and control unit, whose input is connected to the Start bus and the output to the corresponding input of the analog-digital converter being checked, one of the outputs is connected to the first input of the code converter, exemplary digital-to-analog source

30 coraiser, counter, display unit, control unit, program block, switching unit, digital voltmeter, voltmeter code block, control command block, analysis block, matching block, printing unit block, Automatic bus, Manual, Self-test, Setting zero, entered, A reset connected respectively to the first, second, third, fourth, fifth control inputs of the synchronization and control unit, the first output of which is connected to the first inputs of the switching and display units and the second input of the code converter, the second output It is connected to the first inputs of the analog-digital converter of the program block and the third input of the code converter, the third output is connected to the first input of the D / A converter, the second input of the program block and the first input of the voltmeter code block, the fourth output is connected to the fourth input of the code converter, n This output is connected to the second input of the voltmeter code block, the sixth output is connected to the second input of the analog-digital converter, and its output is connected to the second input of the switching unit, the output of the counter, the first in each of the matching unit and the second input of the display unit, the third input of which is connected to the first input of the control command unit, the first output of the analysis unit and the second input of the matching unit, the fourth input is connected to the third input of the matching unit, the first output of the control unit and the second digital input -analogue converter, the fifth and sixth inputs are connected respectively to the first and second outputs of the program block, with the second input of the control command block connected to the first output of the code converter and to the first input b Control, the second and third outputs of which are connected respectively to the seventh and eighth inputs of the display unit, the second input is connected to the second output of the code converter, the third input is connected to the second output of the analog-digital converter, and the third input of the program block and the fourth input is connected to the third output a program block, the fourth output of which is connected to the first input of the analysis unit and the fourth input of the matching unit, the output is connected to the first input of the counter, the sixth output is connected to the third input, and the fourth input with the first output of the digital-to-analog converter / the fifth input is connected to the first output of the control command block, and the sixth input is connected to the third output of the analog-digital converter and the fifth input of the code converter whose third output is connected to the second input of the analysis unit and the third input of the control command block, the fourth input of which is connected to the fifth input of the matching unit with the first output of the voltmeter code block, and the second, third and fourth outputs are connected respectively to the third, the vertical and fifth inputs of the analysis unit, the first, second, and third outputs of which are respectively connected to the second, sixth and seventh inputs of the matching unit, the eighth input, the first and second outputs of which are connected respectively to the output of the first and second inputs of the digital printing unit, with In this case, the first input and output of the digital voltmeter are connected respectively to the second output and the third input of the voltmeter code block, and the second input to the output of the switching unit, the analog outputs of which are connected to the corresponding inputs of the analog voltmeter The digital converter, while its third input is connected to an exemplary source, and the fourth input is connected to the second output of the digital-to-analog converter, the third and fourth outputs of which are connected to the second and third inputs of the counter, and the fourth input is connected to 11C1NY Reset. The drawing shows a structural electrical circuit of the device. The device diagram contains buses Auto 1, Manual 2, Self Test 3, Set Zero 4, Reset 5, Synchronization and Control Block B, A / D Converter (A / D) 7, Switching Unit 8, Model Source 9, Digital to Analog Converter (D / A) 10 , counting, chick 11, program block 12, control block 13, code converter 14, control command block 15, analysis block 16, matching block 17, digitizer block 18, voltmeter code block 19, digital voltmeter 20, display block 21, bus Start 22. Device for monitoring the performance of analog-digital converters zovateley may operate in the following modes: kontrrl ADC performance in automatic mode, control, ADC performance in manual mode, the self-test mode. The control method of the ADC 7 in the automatic mode is as follows. The control of the output code at the address of the selected channel is performed each time the output code of the ADC 7 changes with the arrival of the signal end of conversion (CRC). The control is carried out by C1 comparing the output code of the ADC 7 with the digital voltmeter code 20 which6 {X: 1Y measures the input voltage supplied to input of the selected channel. Codes from the output :: da ADC 7 and the digital voltmeter 20 are compared by the rule: -. laV -lAun are the values of the codeo, respectively, of the digital voltmeter 20 and the ADC 7; D - tolerance on the value of the output code. When a potential 2 signal is received from the Bus Station 2, a logical 1 A / D converter 7 comes to its initial state, and potential information levels of a logical O are set at its information outputs. When a bus 5 Reset signal arrives at a logic level of 1, the monitoring device condition. When entering the tires Manual 3, Self-test 4 signals with a logic level O, the latter block the generation of control signals in the synchronization and control unit 6 of the Manual, Self-test modes. With arrival to the synchronization and control unit b by Shiuam Start 22, Automatic 1 of enabling signals with a logic level of 1, the latter begins to generate trigger pulses that enter the inputs of program block 12, block 19 of the voltmeter and digital-to-analog converter 10 and synchronize the operation of the entire device. When a start signal arrives at the program block 12, it begins to generate a signal for resolving the operation of counter 11. Counter 11 forms a primary, address combination, which from its output goes to the corresponding inputs of the synchronization and control blocks 6, matching 17, switching 8 and display 21 When the address code arrives at the synchronization and control unit, it begins to generate start and synchronization pulses, which are fed to the input of ADC 7, the inputs of the program block 12 and the code converter 14. At this point, the trigger pulse A versatile counter included in the DAC 10 generates control signals for the DAC 10, and at its output sets the maximum negative voltage corresponding to the upper limit of the ADC conversion scale 7, which is fed through the switching unit to the input of the ADC 7, the number of which is determined The combination of the address code and the measuring input of the digital voltmeter 20, which continuously measures the input voltage of the ADC 7, impulses it and converts it into a digital code that is recorded and stored in block 19 of the qi code rovogo, voltmeter between zapusks1mi. When the address binary code and pulses arrive at the control inputs of the A / D converter 7, the Record of the address code whose number is equal to the number of bits in the address code, the A / D converter 7j is started and a single pulse is generated at its outputs. The result of the conversion is the serial information binary code on the third - information code recording pulses. The sequential information binary code from the ADC 7 output simultaneously with the recording pulses of the information code representing the burst, the number of pulses in which corresponds to the number of ADC bits 7, is fed to the corresponding inputs of the code converter 14, is converted into parallel, the result sign is selected and stored between launches. Since the negative numbers at the output of the A / D converter 7 are represented in the reverse code, the inverting of the reverse code is performed in the code converter 14, and the forward codes pass unchanged. Upon completion of writing the code to the converter 14, the output of the control unit 13 to the control unit 13 is given a control resolution signal, the output code, according to which the code from the code converter 14 is copied to the control unit 13, which, using an enable signal from the output of the program block 12, forms a tolerance ) to control the output code of the ADC 7 by the method of tolerance control. The code is written and rewritten into the control unit 13 (when the output changes to discrete) by the End signal, converted from the ADC 7. The control unit 13 contains the Goden and Marriage triggers to record the results of the tolerance control. Consider the operation of the device when the ADC 7 did not pass the pre-control. When the tolerance control does not pass in the control unit 13, a prohibitory signal is generated, which is fed to the corresponding inputs of the Goden and Brac trigger, while the trigger output Braque switches to the state O, and the trigger output Goes to the logical state 1. Signal from the trigger output Braque enters the inputs of the DAC 10 and the matching and indication blocks; in this case, the input of the counter of the DAC 10 is blocked, and the interception signals are formed at its outputs: Disabling of programs entering the input of the block. of program 12, the address barring, which is fed to the input of counter 11-, and the device goes into a cyclical control mode of a conversion scale point that has not passed tolerance control, with a start frequency determined by the synchronization and control unit b, and the ADC 7 digitizes the uninterrupted

the output voltage of the DAC Y. each start of the device, the code recorded in block 19 of the voltmeter code, from its output goes to the inputs of matching blocks 17 and control commands 15, information about the sign of the output code from the output of the code converter 14 and information code arrives to the inputs of the latter, which are written to the appropriate registers and processed. According to the results of processing, from the outputs of the control command blocks 15 to the same inputs of the analysis block 16, the Start and Resolution of the code recording and the output code are received. A signal is sent to the inputs of matching blocks 17 and analysis 16 from the output of program block 12, allowing information to pass to the inputs of analysis block 16. In analysis block 16, the results of digital voltmeter code conversions and information code, reduced to the same dimension, are evaluated by logical addition operations , subtraction and shift, determination of the sign of the difference of these codes, determination of the real conversion error of the ADC 7. The signals formed at its outputs, together with the information code, arrive at matching the inputs of the matching block 17. The other inputs of it are the address code (number of the controlled channel), the digital voltmeter code taking into account the sign and the Scrap signal. The matching unit provides matching of signals arriving at the digital printing unit 18 in amplitude and provides galvanic isolation between the digital printing unit 18 and the device.

When the Ready signals from the digitizing unit 18 and Start start coincide, the readiness signal of the digital block 18 is printed and the information printed on the inputs of the matching unit 17 is printed on the tape. When the signal arrives at its input, the Marriage is locked on the input and the next time the device starts, it blocks the input to which the trigger enable signal is applied. The digitizer 18 stops printing the information. In order to continue monitoring the remaining points of the ADC 7 conversion scale, it is enough to quickly send signals O to the synchronization unit 6 and then 1 to the synchronization unit 6. At the same time, the device takes the ADC conversion point 7, which has not passed tolerance control, from the looped monitoring mode, and proceeds to the program control, and the digitizing unit 18 continues to print information about the conversion results.

If the tolerance control passes without rejecting, then the Triggered Marriage, Gadden triggers do not switch and from the output of the control unit 13 to the corresponding input of the display unit 21, a Signal signal is output, which is continuously displayed during the control process.

If the tolerance control serial information binary

 when the code passed without issuing the Marriage signal, then the fourth output of the program block 12 is issued with the permission command for the fourth input of the DAC 10, and the number recorded in the DAC counter 10 will decrease by one. At the next

When the ADC is started up, the output voltage at the similar output of the DAC 10 decreases by one low-order sampler and the device begins to monitor the performance of the ADC 7. As it passes

0 checks of the tolerance control in the range of the output voltage of the DAC 10 against minus and ohuis O, the voltage at the output of the DAC 10 begins to increase by the value of the youngest

5 discrete DAC 10 in the range from O to Exit rtioiK If the test at this address has passed without rejection, the digitizer 18 prints the following information in the tenth code:

Channel number to be tested (address)

 the output voltage of the DAC 10, taking into account the polarity sign, the number of samples corresponding to the output code of the ADC 7, taking into account the sign, the magnitude of the conversion error, taking into account the sign,

 if the control unit has issued a signal

Marriage, it is printed on the tape. When the address arrives at the input of the switching unit 8, the latter, in accordance with the address combination, connects the next input of the A / D converter 7 to the analog output of the D / A converter 10, orienting to the control input of the counter 11 receives the same address combination as on the switching unit 8, and The ADC 7 turns on in accordance with it the channel to which the voltage is applied from the output of the DAC 10, and the monitoring process described above begins. In a similar way, all

l channels of the ADC 7, and after the end of the control of the last channel, from the first output of the program block 12, the first input of the counter 11 receives a inhibitory signal, through which the last goes to the initial state, and

the output of the program block 12 to the input of the display unit 21 is issued a command to terminate the control and is indicated on it. Verification complete, Valid. Continuously on each launch of the device, the latter monitors the time parameters of the signals. The end of the conversion and the recording of the information code, for this, an enable signal is output from the control command block 15 to the input of the program block 12

timing control. The inputs of the program block 12 receive signals respectively. The end of the conversion and the serial information code from the outputs of the ADC 7 and the write signal of the address code, relative to the last pulse of which the counter is started, the signals from which are decrypted and compared with the input signals are formed taking into account possible time variations of the input signals, if the control signals do not match the input and the program block 12 generates a signal pulses, which blocks the start signal at its input and from the other output is fed to the input of the display unit. Monitoring the time parameters of the mutual arrangement of signals. The end of the conversion and recording of the information code is necessary for fixing short-term failures, failures, asynchronous issuance, as well as synchronous failures of the signal of the sequential information code, recording of the information code and, end of testing at one frequency with faults in the control paths of the control 1 th ADC 7.

In the process of automatic monitoring, the display information 21 is continuously displayed and the following information is displayed in the decimal code; number of the controlled channel, the output code of the ADC 7, taking into account the sign Gauden, Marriage Check is over. In display unit 21, the binary code is transferred from the AHP 7 to the decimal. The number of hundreds, tens, units is memorized by a counter and is rewritten into the corresponding bits of the display register.

The operability of ADC 7 in manual mode is performed when the synchronization and control unit is received on buses 1,2,4 and 5 signals with a logic level O, and through buses Manual 3, Start 22 signals with a logic level 1, while the synchronization unit and control b starts to generate start-up pulses arriving at the corresponding control inputs of the ADC 7, and the structure of the address code is set manually from the controls located in the synchronization and control unit 6, from the first output of which the address code is assigned to the same name The codes of the converter 14, the display units 21 are switched to 8. When the address code arrives at the switching unit 8, the latter, in accordance with the address combination, connects to the selected ADY 7 input the voltage of the exemplary source 9, the output voltage of which can vary from minus 1x30 ° Unbixvyiin which is fed to the measuring input

digital voltm. 20, and it continuously measures its magnitude and displays. When control address inputs of the ADC 7 receive the address code signals and write the address code, the ADC 7 is started, the latter, in accordance with the address combination, includes the channel to the input of which the output voltage is supplied from the reference source9, the output code of the ADC through the code converter

0 14 and the control unit 13 is fed to the third input of the display unit 21 and is continuously displayed. By setting different combinations of the address code in the synchronization and control unit 6, you can check the conversion accuracy at any point on the conversion scale for each channel of the ADC 7 by a known input voltage indicating on the display unit 21,

0 - in addition, the information on the number of the controlled channel is displayed on the latter.

Manual operation of the device is necessary when analyzing complex parametric failures in a controlled ADC 7 and performing adjustment work.

to diagnose the health of the device, the latter has a self-test. Transition to mode

0 self-test occurs when the synchronization unit 6 arrives at the bus. Self-test 3 potential sigNSha with a logic level of 1, while the device can work either

5 in automatic or manual modes.

Consider the operation of the device in the manual mode, since the automatic self-test mode is similar to the automatic checking of the DF-7, with the only difference that instead of the output, the F-7 of the sequential information and recording of the information code uses control inputs, binary address

5 code, record of the address code, and the signal. The end of the transformation is formed in the control unit 13. When a logical 1 signal arrives at the synchronization and control unit b on bus 4

0, the latter generates a self-test feature signal, which, from its output, enters the input of the code converter 14 and blocks the output signals from the ADC 7 and allows

5 passing the control signals of the address binary code and writing the address code 1 coming from the output of the synchronization unit 6 to the inputs of the code converter 14 of the same name, with hO: the number of bits and sync pulses in the structure of these signals corresponds to the number of bits in the output information code and the number of write pulses information code. The monitoring process is carried out in the same way.

as in the control with the OCS 7, all changes in the structure of the address code are set from the synchronization and control unit 5 manually. A sign of correct device operation is the matching of the address binary code and the decimal code on the display unit. The self-test mode allows you to test the operation of all digital nodes and blocks of the control device.

The use of this device makes it possible to qualitatively increase the accuracy control of multichannel ADCs, determine the magnitude and sign of the error, document the results of the control, which makes it possible to eliminate the omission of defective products and increase the reliability of the products.

Claims (1)

Invention Formula A device for monitoring the operability of analog-digital converters, containing a synchronization and control unit, the input of which is connected to the Start bus, and the output with the corresponding input of the analog-digital converter under test, one of the outputs of which is connected to the first input. code converter, model source, digital-to-analog converter, counter, display unit, characterized in that, in order to expand the functionality of the device, a control unit, a program block, a switching unit, a digital voltmeter, a voltmeter code block, a control command block, an analysis block, are introduced, matching unit, digital printing unit, automatic, manual, self-test buses, zero setting, reset, connected to the first, second, third, fourth, fifth control inputs of the synchronization and control unit, respectively the first output of which is connected to the first inputs of the switching and indication units, and the second input of the code converter, the second output is connected to the first inputs of the analog-digital converter, the program block and the third input of the code converter, the third output is connected to the first input of the digital-analog converter, the second input the program block and the first input of the voltmeter code block, the fourth output is connected to the fourth input of the code converter, the fifth output is connected to the second input of the voltmeter code block, the sixth output connected to the second input of the analog-digital converter, and its input is connected to the second input of the switching unit, the counter output, the first input of the matching unit and the second input of the display unit, the third input of which is connected to the first input of the control command unit, the first output of the analysis unit and the second input of the matching unit, the fourth input is connected to the third input of the matching unit, the first output of the control unit and the second input of the digital-to-analog converter, the fifth and sixth inputs are connected to the nepBbjM and the second outputs of the program block, the second input of the unit control coma is connected to the first output and to the first input of the control unit, the second and third outputs of which are connected respectively to the seventh and eighth inputs of the display unit, the second input is connected to the second output of the pre The third code input is connected to the second output of the analog-digital converter and the third input of the program block, and the fourth input is connected to the third output of the program block, the fourth output of which is connected to the first input of the analysis unit and the fourth input of the matching unit, the fifth output is connected to the first input of the counter , the sixth output is connected to the third input, and the fourth input to the first output of the D / A converter, the fifth input is connected to the first output of the control command block, and the sixth input is connected the third output of the analog-digital converter and the fifth input of the code converter, the third output of which is connected to the second input of the analysis unit and the third input of the control command block, the fourth input of which is connected to the fifth input of the matching unit and the first output of the voltmeter code block, and the second, third and fourth outputs are connected respectively to the third, fourth and fifth inputs of the analysis unit, the first, second, third outputs of which are respectively connected to the second, sixth and seventh inputs of the matching unit The eighth input, the first and second outputs of which are connected respectively to the output, the first and second inputs of the digital block, the first input and the output of the digital voltmeter are connected respectively to the second output and the third input of the voltmeter code block and the second input to the output of the switching unit, the output outputs which is connected to the corresponding inputs of the analog-to-digital converter, while its third input is connected to an exemplary source, and the fourth input is connected to the second output of the digital-to-analogue converter bodies, third and fourth outputs of which are connected to second and third inputs of the counter, and the fourth input is connected to the bus reset. Sources of information taken into account during the assessment 1. USSR author's certificate No. 399059, cl. H 03 K 13/02, 07/27/71