SU1571657A2 - Device for reproduction of service information from magnetic record carrier - Google Patents

Abstract

The invention makes it possible to reduce the error in the result of reproducing overhead information from a magnetic recording medium produced on a separate track on autonomous multichannel recording devices when exposed to significant destabilizing factors. A third additional counter, a third additional trigger connected by the first setup input to the first output of the code information selector, a third additional AND element whose first input is connected to the output of the third additional trigger, the second input to the second output of the code information selector, and an output through the pulse frequency divider is connected to the second setup input of the third additional counter and to the second reset input of the third additional trigger. 2 Il.

Description

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(61) 1458887

(21) 4609271 / 24-10

(22) 11/28/88

(46) 06/15/90. Bit. Nb 22 (72) B.N.Cot

(53) 681.846.7 (088.8)

(56) USSR author's certificate

N 1458887, class G 11 May 5/09, 12/24/87.

(54) DEVICE FOR REPRODUCTION OF SERVICE INFORMATION FROM MEDIA MAGNET RECORDING

(57) The invention makes it possible to reduce the error in the result of reproducing service information from a magnetic recording medium produced on a separate track on autonomous multi-channel recorders when exposed to significant destabilizing factors. A third additional counter, a third additional trigger connected by the first installation input to the first output of the code information selector, a third additional element I} of which the first input is connected to the output of the third additional trigger, the second input to the second output of the code information selector, and the output through the pulse frequency divider under ™ keys to the second setup input of the third additional counter and to the second reset input of the third additional trigger. 2 Il.

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The invention relates to magnetic recording, in particular, to devices for reproducing service information from a magnetic recording medium, and is an improvement of the device according to the author. St. K 1458887.

The aim of the invention is to reduce the error in reproducing the overhead information from the magnetic recording medium.

FIG. 1 shows a block diagram of the device; in fig. 2 - timing diagrams for the operation of the device.

The device contains amplifier-shaper 1, magnetic head 2, selector 3 of code information, block 4 elements AND, the number of which is equal to the number of bits in the code group, displaying the current time, block 5 of counters, block 6 of flip-flops (the number of flip-flops is equal to the number of elements, comrade 4), digital recorder 7, multiplexer 8, first counter 9, first element 10, waiting multivibrator 1 1, delay element 12, second counter 13, first trigger 14, second trigger 15, second element 16, third counter 17 , third trigger 18. third element, And 19, divisor 20 pulse frequency.

The device works as follows.

The result of reproduction from the carrier of the GM recording is transferred from the magnetic head 2 to the amplifier 1. From the output of the amplifier 1 to the selector 3 of the code information a pulse is sent.

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A data (Fig. 2a), consisting of sync pulses and information pulses that are shifted relative to them by half a clock period. The code information selector 3 implements the separation of clock pulses and information pulses.

Information pulses (Fig. 26) from the first output of the selector 3 of the code JQ information arrive at the first counting I input of the counter 17 and at the installation input of the trigger 18. Synchronizing pulses (Fig. 2c) from the second output of the selector 3 of the code information post jj fall on the second which element is AND 19,

Counter 17, trigger 18S element And 19 and the divider 20 pulse frequency, connected between the element And 19 and second

Eye the installation input of the counter 17, form the selector information pulses from false pulses interference.

The algorithm for selecting informational and false pulses is determined by the counting counter of the counter 17 and the pulse frequency divider 20.

With the selected conversion factors, where n is the number of pulses in a single bit burst, the selection algorithm of information pulses is the arrival of the first counting input of the counter 7 of a continuous burst consisting of no more pulse than pulses. If there are fewer pulses in the bundle, these pulses are perceived as false. Selection of informational and localized pulses is performed as follows.

The first pulse (or a subsequent pulse, a multiple of the division factor of the pulse frequency divider 20) of the information packet (FIG. 36) activates the trigger 18 (FIG. 2c allowing the clock pulses (FIG. 2c) to pass through) And 19 to the input of the divider 20 pulse frequency (Fig. 2b2). At the output of the 20 o'clock H divider, as a result of dividing a part of the clock pulses (Fig. 2w), subsynchronization pulses are generated

Pulses under synchronization set the trigger 18 to the initial state, thus preparing it for receiving the next series of informational impulses.

In addition, the subsynchronization impulses synchronize the operation of counter 17, if before

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the counting input as a result of a fault arrived distorted (not a multiple of the conversion factor) a series of pulses (Fig. 2c, moments tg, t, and),

For the case when the recalculation coefficients of the counter 17 and the divider 20 frequencies are equal to p / 2 and there are no loss among the information and synchronizing pulses, and also no false pulses, from the output of the counter 17 (Fig. 2a) to the first inputs of the And 4 elements and the trigger 14 two impulses are received for each information packet,

When one or several pulses fall out of the burst, but not more than p / 2 pulses, a single pulse is formed at the output of counter 17 (Fig. 2v4, time t), which, like the two pulses generated in the previous case, triggers trigger 14 or the formation of the information bit on one of the elements And 4,

If in the reproduced packet there will be less jn / 2 pulses (Fig. 26,

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The pulses are not generated, which corresponds to the reproduction of the result of recording with impulse noise.

The clock pulses from the second output of the code information selector 3 are fed to the counting output of the counter 13, which forms a frequency corresponding to the discharge frequency in the information groups. The signal of the counter 13 in the presence of the light signal of the code information from the output of the trigger 14, passes through the element 10 to the first counting input of the counter 5. The light signal of the code information from the output of the trigger 14 starts the waiting multivibrator 11, which generates short synchronization pulses of the counter 5 and the counter 13 In this case, the code information illuminating signal ends at the moment when the signal from the output of the last bit of the counter 5 arrives at the second input of the trigger 14,

The counter 5 generates switching pulses, by means of which in the elements 4 and 4 the conversion of a serial code into a parallel-serial code is performed. A parallel-serial code from the outputs of the And 4 elements triggers triggers 6,

the reset of which is provided by the pulses of the waiting multivibrator 1 1, delayed delay elements 12.

The code information from the outputs of the flip-flops 6 is fed to the multiplexer 8, which analyzes their state, and to the counter 9. In the case of forbidden code combinations, the multiplexer 8 generates a signal that triggers the trigger 15, which overwrites the AND 16 element. code information to counter 9 by a signal from a standby multivibrator 11 passing through an open element I 16. At the same time, counter 9 operates in a counting mode that ensures the transmission of reliable code information to a digital signal Gistr 10, which displays the reproduced overhead information.

Claims (1)

Invention Formula Device for reproducing service information from media nitny records on auth St. No. 1458887, characterized in that, in order to reduce the error in reproducing service information from the magnetic recording medium, a third additional counter is inserted in it, the counting input of which is connected to the first output of the code selector, and the output to the first inputs of the AND block and the first installation input of the first additional trigger, the third additional ger connected by the installation input to the first output of the code information selector, the third additional element I, the first input of which is connected to you Odom third additional latch, the second input - to the second output selector code information, and an output pulse inputted through the frequency divider - a mounting additional input of the third counter and an additional input of the third flip-flop is reset. 0 five