SU370736A1 - DEVICE FOR IMITATION OF DISTORTIONS OF TELEGRAPHIC SEARCHES - Google Patents

Description

one

This invention relates to the field of telegraphy, in particular to telegraph distorts.

Devices are known for simulating telegraph signal distortions for testing and tuning receiving telegraph devices, as well as for measuring the correcting ability of start-stop and synchronous telegraph receivers. Such devices make it possible to obtain by shifting the fronts of received parcels of a distortion of the type: lengthening the beginning — shortening the end of the parcels; lengthening the end - shortening the beginning of parcels; lengthening of currentless packages during shortening of current; lengthening of current parcels during shortening of currentless ones.

Devices for simulating telegraph cell distortions are also known, comprising a master oscillator, a variable division divider, a distributor, a test signal generator, a parcel transition isolation circuit, AND circuit, OR circuit, noise-like pulse generator, output shift register, NOT circuit and output block However, the known devices introduce only regular (constant in magnitude) distortion, the magnitude of which is determined by the position of the switches.

Meanwhile, the work of phasing and other

nodes, as well as the correcting ability (noise immunity) of the majority of real cases, depends more on the random displacement of the fronts of received telegraphic packages. Therefore, when using the known device for measuring the corrective method of telegraph receivers, a large error is introduced to adjust and test the phasing, recording and other receiving equipment of discrete communication systems.

In the proposed device, the increase in imptach of random distorted telegraph signals according to a predetermined random law is achieved by the fact that the outputs of the distributor are connected to the inputs of additional circuits "AND, whose outputs through an additional circuit" OR are connected simultaneously to one of the inputs of the said distributor and to

the input of the shift register, and the outputs of the shift register are connected to other inputs of the additional AND circuits and to one of the inputs of the mentioned PI circuits, whose outputs through the OR circuits are connected to

the inputs of the Sdziga output register, and the output of the latter is connected to the second inputs of the mentioned AND circuits and simultaneously to the counting trigger input on one ii3 inputs of the output AND circuit, to the second input of which

the output of the mentioned trigger is connected.

The proposed device can be used in telegraph distorts that imitate the random law of variation of edge distortion, crushing, etc.

FIG. 1 and the circuit of the proposed device for simulating edge distortion; in fig. 2 and 3 - time diagrams of his work.

The device consists of the following components: master oscillator 1; divider 2 with variable division factor; 5 test emuls generator; a circuit 4 for isolating positive and negative transitions of a code combination; 5 shum-like emulsion generator; logic diagram "ЫЕ 6; logical scheme "OR 7; valve 8 with a variable distribution coefficient; coincidence schemes 9j-9p; shift register 10, the duration of the output signals of which determines the probability of a certain amount of distortion; Hi-lln match schemes; logical circuits "OR 12; output register 13 shift; trigger 14 with a counting start; a coincidence circuit 15 providing, together with the trigger 14, the operation of the output device 16 only from impulses distributed randomly; output device 16; switch 17, which specifies regular type distortion: shortening of the current parcel from the beginning and shortening of the currentless parcel from the end; switch 18 defining regular type distortion: shortening of the current parcel from the end and shortening of the currentless parcel from the beginning.

FIG. 2 and 3, the following notation is accepted: constant displacement A of the front of the received parcel; random offset B of the same front.

Elements that set the circuit to its original state, in FIG. 1 not shown.

The proposed device works on the principle of simulating random displacements of the fronts of received parcels with a mathematical expectation determined by the value of regular distortions. The latter can be formed as follows. From the code combination coming from the generator 3 of the test signals (OUT 3, see Fig. 2) with the arrival of the clock of the master oscillator 1, pulses corresponding to the positive and negative transitions of the parcels are extracted (I and I and I, and fed through switches 17, 18 and one of the OR 12 schemes to the output register 13, controlled by the clock pulses of the master oscillator 1, the frequency of which is set by the divider 2 with a time division factor. The pulses at the output of the shift register 13 (out / 5) appear with a delay determined by The position of the switches 17, 18. As a result, the pulses corresponding to the transitions of the parcels are shifted by some constant value relative to their actual position. The random law on the resulting regular distortions is superimposed in the schemes 111-lln by means of the distributor 8 and the shift register / 6. The shift register W, the number of outputs of which corresponds to the number of 5 discrete steps (areas) approximating the distribution function of random distortions, is controlled by feedbacks through the circuits 9i-9 " Day into the scheme "OR 7 distributor 8, controlled, 10, in turn, noise-like pulses from the generator 5 (o. 5, see FIG. 3). The duration of the output signals from the shift register 10 (respectively, the input signals of the coincidence circuit // i-lln, defined by 15 time intervals, through which signals appear at the outputs of the distributor 8, is proportional to the size of the approximating areas. The duration of the signal at the first output of the register is 10 20 ( Ill) corresponds to the minimum area taken as a unit; the duration of the signal at the second output of the shift register 10 (in. llz) is determined by the time interval required for the operation of so many bits of the 5 distributor 8, how many times the second approximating area is more than one, etc., i.e., the distributor 8 has a variable distribution coefficient. The number of bits is determined by some 0 number t, indicating how many times the maximum approximating area is larger than a single one. 8 and connecting in a certain way (depending on the desired distortion distribution law), the outputs of the shift register 10 with the PI-P schemes match, any random law can be set.

Thus, in the initial state, from the first output of the shift register 10, a signal is received that prepares the operation of the circuit 5i and Hi coincidence. With the arrival of the first noise-like pulse, the PI coincidence circuit is triggered and generates a signal that passes 5 through the circuit OR 7 (out 7), sets the distributor 8 to the initial state, i.e., throws "1 into its first bit and advances" 1 in the second digit of the shift register 10. In this case, the PIA (in. Llz) circuits 9 and Hz coincide with the signal from the second output of the distributor and hold until the signal from the second output of the distributor 8 arrives. Then the coincidence circuit 9 operates and issues a signal, which again sets the distributor 8 to the initial state and advances "1 to the third digit of the shift register 10, and so on.

With the arrival of a pulse from the shift register 13, corresponding to a constant displacement of transitions and prohibiting the passage of noise-like pulses to the distributor 8, one (// g) from the lli-lln coincidence circuits is triggered, which is prepared for operation at this moment by a signal from the shift register 10. The impulse from the lli coincidence circuit arrives

through the circuit "OR 12" into the shift register 13, runs with the frequency of the clock pulses and through the trigger 14 and the coincidence circuit 15 arrives at the output device 16. The trigger 14 is set in such an initial state that with the arrival of regular distortions it outputs a inhibitory signal to the circuit 15 matches; with the arrival of random distortions, the trigger is thrown and outputs an enable signal to the coincidence circuit 15 (o. 14.

With a significant number of distributor bits 8 and shift register 10, each of them can be made in the form of two series-connected valves with the number of bits fn miXm2; n niXnz, which will provide a small consumption of binary elements.

Thus, the proposed device has great functionality, i.e. with a slight complication of the entire device, telegraphic packages are distorted according to given random (quasi-random) laws. Such a construction of a device for simulating the edge distortions of telegraph parcels makes it possible to use it to measure the correcting ability of telegraph receivers, to conduct qualitative tests of receivers and their individual nodes. The proposed device can be used in enterprises engaged in the development, manufacture and operation of telegraph equipment, receivers of discrete communication systems, etc.

Subject invention

A device for simulating telegraph cell distortions, comprising a master oscillator, a divider with a variable division factor, a distributor, a generator of test signals, a circuit for selecting transitions of parcels, an AND circuit, an OR noise generator, an output shift register, an NOT circuit and an output unit , characterized in that, in order to improve the accuracy of imitation of random distortion, the outputs of the distributor are connected to the inputs of the additional circuits "AND, whose outputs through the additional circuit" OR alternately to one of the inputs of the said distributor and to the input of the register

shift, and the outputs of the shift register are connected to other inputs of the additional AND circuits and to one of the inputs of the said AND circuits, the outputs of which through the OR circuits are connected to the inputs of the output shift register, and the output of the latter is connected to the second inputs of the mentioned circuits "And both at the same time to the counting input of the trigger and to the anomaly from the inputs of the output circuit" And, to the second input of which is connected

output of the mentioned trigger.

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