SU1352532A1 - Device for checking errors of magnetic recording and reproducing channel - Google Patents

Abstract

The invention relates to the field of instrumentation. The purpose of the invention is to reduce the time of control and increase its accuracy. The device contains a magnetic recording-playback channel 1, a clock generator 2, a shaper 3 codes, a 4 error detector, a 5 error counter, a memory element 6, an indicator 7, a comparison block 8, an AND 9 element, a 10 clock counter, 11 pulse generators and 12 , trigger 13, the element OR 14 and the control element 15. The introduction of new elements and the formation of new connections between the elements of the device make it possible to indicate the maximum value of the error rate, which is obtained as a result of conducting several cycles of measurement of this parameter. 1 il. about (L with: 00 01 yu SP Ro

Description

The invention relates to instrumentation, in particular to a magnetic recording technique, and can be used in built-in means of monitoring magnetic recording equipment for monitoring write errors — to reproduce digital information signals.

The purpose of the invention is to reduce the control time and increase its accuracy.

The drawing shows a block diagram of the proposed device.

The device contains a magnetic recording-reproduction channel 1, a clock generator 2, a shaper 3 codes, a 4 error detector, a 5 error counter, a memory element 6, a digital indicator 7, and also a comparison unit 8, an And 9 counter element 10 clock cycles, the first 11 and the second 12 pulse shapers, the trigger 13, the IL 1 element and the control element 15.

The output of the clock generator 2 is connected to the input of the imaging unit 3 of the code, the information output and output of the clock sync signal of which are connected respectively to the information and synchronization input of the monitored magnetic record-reproduction channel 1, the sync signal output also connected to the counting input of the 10 clock counter, output connected to the input the first shaper 11 pulses.

The information output and the clock output of the playback of the monitored recording-reproduction channel 1 are connected respectively to the information and clock inputs of the 4 error detector, the output connected to the count input of the 5 error counter.

The outputs of the bits of the 5 error counter are associated with the corresponding information inputs of the memory element (register) 6 and with the first group of inputs of the comparison block 8.

The output of the first pulse shaper 11 is connected to the first input of the AND 9 element, and through the second shaper 12 pulses to the first inputs of the trigger 13 and the OR 14 element. The outputs of the memory element 6 are connected to the signal inputs of the digital indicator 7 and to the second group of inputs of the second comparison unit 8, the output connected to the second input element And 9, the output of which

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a non-control input of the parallel input of information of the memory element 6.

The output of the control element 15 is connected to the installation inputs of the 10 clock counter and the memory element 6, as well as to the second inputs of the trigger 13 and the OR element 14, the output connected to the installation input of the error counter 5. The output of the trigger 13 is connected to the input of the inclusion of a comma of the second bit of the digital indicator 7.

The proposed device works as follows.

Before starting the measurement, the device is reset to the initial state by applying a pulse command from the control element 15, a 10 clock counter, an error counter 5 and the memory element 6 are set to the zero state, and the trigger 13 is reset to the initial state. zeros flash and there is no comma luminescence.

A test signal generated by the code shaper 3 (e.g., in the form of a pseudo-random symbol sequence) is recorded on a magnetic recording medium and played back in a controlled magnetic recording-reproduction channel 1,

The error detector 4 detects errors in the reproduced signal, which are counted by the error counter 5, and information on the number of errors is fed to the information inputs of the memory element 6 (register) and to the first group of inputs of the comparison unit 8. The 10 clock count counts the amount of information recorded.

The average practical value of the error rate is 1 failure per 10 bits, and therefore the error rate is indicated with a factor of 10. To ensure the accuracy of the measurement result of the coefficient

errors, the amount of information recorded for monitoring must be at least 100 times greater than 10 bits. In view of this condition, the counter counting module 10 is selected to be 10,066,329 clock cycles (bits).

After counting this number, i.e. at the time of the negative differential output of the counter 10, the output of the first driver 11

a pulse is generated that goes through the AND 9 element (opened during the first measurement cycle) to the control input of the memory register 6 and writes the contents of the 5 error counter into it.

At the moment of termination of the output pulse of the first driver 11 is formed at the output of the second driver 12. This pulse goes through the element OR 14 to the set input of the error counter 5 and sets it to the zero state, and also switches the trigger 13. The output signal of the trigger 13 turns on after the second digit of the digital indicator 7. Subsequently, the state of the trigger 13 does not change.

A comma on display 7 indicates that the first error rate measurement cycle has ended. In this case, the digital indicator 7 highlights the state of the memory element (register) 6 in which the information on the measured number of errors for the first measurement cycle is recorded.

The range of measured values of the error rate with a four-bit indicator 7, a multiplier of 10, a 12-bit counter of 5 errors and a comma after the second bit is from 00.01x10 (10) to 40.96x10 (4.096x10), which is is quite sufficient, since for modern equipment of accurate magnetic recording the value of the error rate lies within

from 10 to 10 7

Since before the next, second measurement cycle, the error counter 5 is reset, in the second cycle, the counter 5 counts the errors of this cycle only.

Unit 8 compares the information on the counted number of errors in a given measurement cycle with the information stored in memory register 6, i.e. with information on the number of errors recorded in one of the previous (in general) cycles. In this case, at the end of this cycle, the contents of the 5 error counter are recorded in the memory register only if the number of errors counted in this cycle exceeds the number of errors of the previous (in parity) cycle or (in general) maxi

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the maximum number of errors fixed in one of the previous cycles. If the output signal of the comparator unit 8 is exceeded, it gives permission for the output pulse of the former 11 to pass through the AND 9 element and to the control input for the parallel input of information from the memory register 6.

Thus, in the proposed device, the maximum value of the error rate, which is obtained as a result of conducting several measurement cycles of this parameter, is indicated.

The proposed device, compared with the known, represents the results of the control in the form of a digital magnetic recording equipment that is ready for evaluation, which is not required after completing the monitoring process to perform any calculations, which reduces the monitoring time and increases its accuracy by eliminating the subjective error in the monitoring result.

Claims (1)

Formula of the invention A magnetic recording-reproduction channel error control device containing a clock generator connected to the code generator, whose information output and the output of the recording clock signal are connected to the corresponding inputs of the controlled magnetic recording-reproduction channel, which is connected by its information output and output of the playback clock signal with the corresponding inputs of the error detector, the output of the error counter connected to the counting input, as well as the clock counter, the And element, three A hero, a digital indicator and a control element, characterized in that, in order to reduce the monitoring time and increase its accuracy, the first pulse shaper connected to the output of the clock counter is entered into it, the output connected to the first input of the And element and through the second pulse shaper - to the first the inputs of the OR element of the trigger, the output associated with the enable input of the second digit of the digital indicator, the memory element connected between the outputs of the error counter and the inputs of the digital indicator, block 13525326 Comparison between the output-inputs of the OR element and the trigger, the error counter and the outputs of the electronic keys, the output of the control element, the memory element, and the output connected to the output of the element OR are connected to the second input of the element connected to the control error, and the output of the clock sync signal to the input of the memory element, and to its setup of writing the code generator to the matching input, the installation input with the counting input of the counter of the counter counts, as well as to the second cycles.