SU1383384A1 - Device for simulating data transmission systems - Google Patents

Abstract

The invention relates to a data transmission technique and digital computer technology and can be used in the development and simulation of data transmission systems. The purpose of the invention is to expand the functionality of the device by simulating the re-transmission of messages in the event that a receipt is not received. The goal is achieved by introducing into each simulation channel the transmission of information of the clock generator, a reversible counter for the length of the transmitted message queue, a repetition time counter for the transmission of messages, two OR elements, two triggers, and the third through ninth elements I. The device allows you to more accurately simulate real transmission systems data with a star structure. 1 il.

Description

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The invention relates to a data transmission technique and digital computer technology and can be used in the development and simulation of data transmission systems.

The purpose of the invention is to expand the functionality of the device by simulating the re-transmission of messages in the event of non-receipt of receipt results.

for a set period of time.

If there is no receipt for the period of time determined by the frequency of the generator 22 and the width of the counter 23, the overflow pulse from the output of the counter 23 passes through the OR element 24 to the input of the And b element, simulating a retransmission of the message to the communication channel. In the case of re, as well as subsequent

The drawing shows the scheme of the device-10 absence of the receipt of the procedure of repetition. As the generator 22 and the counter 23 of the collection, the device contains a general generator, they are received only with the arrival of the receipt with

random stream of pulses transmitted by the output element And 9.

messages, a pulse counter 2, a Generator group with a HE 5 element, as well as channels 3 of the transmission information simulation module And 6 are designed for modeling, and in each channel, the first generation of error streams arising into the capacitor 4 random interference pulses in connection with the transmission of data from the center to the transfer of messages, the first element is NOT 5, the main station to all slaves, the first element I 6, counter 7, the second ele-B random points in time, the ment HE 8, the second element I 9, the counter 10E 5 control signals appear, generator 11 s uchaynyh interference pulses 20 pulses prohibiting passage through

when sending receipts, the counter 12, the gap 13 and the seventh 14 elements, the reversible counter 15 is the length of the queue of transmitted messages, the trigger 16, the fifth element and 17, the first trigger 18, the third element And 19,

Element I 6. This simulates the distortion (loss) of the message during its transmission over the communication channel (from the central station to the slaves). If the output of the generator 4 pulse is not received, then the input

the first element OR 20, the fourth element 2 of the element AND 6 receives a signal, permitting AND 21, a generator of 22 clock pulses, counting the passage of pulses through the cell 23 of the time of message transmission, the second element OR 24, counters 25

and 26, eighth, 27 and ninth 28 elements I.

ment and 6.

Similarly, the generator 11, the elements HE 8 and I 9 are designed to simulate the loss of the receipt codes, the post device works as follows. The generators 1 of a random stream of pulses, at random points in time, generate pulses that arrive at the input of a counter of 2 pulses, as well as at the inputs of elements And 13 and 14, to the model data stream

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Oral (due to the presence of noise in the reverse link).

The pulses from the output of the element And 9, simulating the transfer of receipts in the reverse channel, reset the counter 23 and the generator

from the central station to all subordinates- 35 22 clock pulses, stopping the countdown

set for waiting the receipt of the time interval, and also go to the subtracting input of the counter 15 through the element And 17, since the latter is opened by the potential from the exit of the trigger 16, set to one at the moment of the beginning of the data channel buffer filling. The same potential opens the element 21 and through which the pulses from the output of the element 9 and 9 arrive at the elements in the unit state and thereby blocks 45 or 20 and 24 and then to the input of the element prevents the passage of pulses from the generator 6, to the model, the output from the buffer to the channel is barely 1 through element I 13 and resolves their subsequent data block, (simultaneously with walking through element 14 and element 27, the contents of counter 15 are reduced by the summing input of counter 15, modeled by one.

Filling the buffer of the transmission channel When the contents of the counter 15 of the station data when the latter is occupied. The first 50 Wits is equal to zero, the zero pulse from the pulses entering the buffer, the meter counter 15 is fed to the trigger input

ny.

At the initial moment of time, the triggers 16 and 18 are in the zero (stranded) state. The zero potential, applied from the output of the trigger 18 to the inverse input of the element And 13, permits the passage of a pulse from the generator 1 through the element And 13, the elements OR 20 and 24 to the input of the element And 6. The pulse from the output of the element And 13, entering the input of the trigger 18, sets the last trigger 16 to one state, and subsequent pulses do not change this state.

The pulse from the output of the element OR 20 starts the generator 22 clock pulses. The clock pulses from the generator 22 are fed to the counter 23, and the waiting for the transmitted data is simulated.

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16 and sets it to the zero state. In this case, the elements And 17 and 21 are closed and the element And 19 is opened. The receipt from the element And 9 passes through the element And 19 to the input of the trigger 18, sets it to the zero state, thus preparing the passage of the next pulse from the generator 1 directly to the transmission channel

for a set period of time.

If there is no receipt for the period of time determined by the frequency of the generator 22 and the width of the counter 23, the overflow pulse from the output of the counter 23 passes through the OR element 24 to the input of the And b element, simulating a retransmission of the message to the communication channel. In the case of re, as well as subsequent

The generator with the element HE 5, as well as with the element 6 is designed to simulate the flow of errors that occur in the communication channel when data is transmitted from the central station to all slaves. At random moments of time, the input HE 5 appears control signals prohibiting the passage of pulses through

Element I 6. This simulates the distortion (loss) of the message during its transmission over the communication channel (from the central station to the slaves). If the output of the generator 4 pulse is not received, then the input

element 6 receives a signal allowing the passage of pulses through

Wits equal to zero, the zero pulse from the counter 15 is fed to the trigger input

16 and sets it to the zero state. In this case, the elements And 17 and 21 are closed and the element And 19 is opened. The receipt from the element And 9 passes through the element And 19 to the input of the trigger 18, sets it to the zero state, thus preparing the passage of the next pulse from the generator 1 directly to the transmission channel

data through the element And 13, the elements OR 20 and 24, and also prohibits the passage of a pulse to the summing input of the counter 15 through the element And 14.

In the event of overflow of counter 15, the signal from its overflow exit prohibits the passage of successive rates into the buffer through element 27 and allows them to pass through AND 28 to counter 12, counting the number of orders lost due to buffer overflow.

Counter 2 is designed to count the number of messages prepared by the central station for transmission. Counter 25 counts the number of messages transmitted by the subordinate station, counter 26 — the number of message repetitions, counters 7 and 10, respectively, the number of receipts transmitted by the subordinate station and received by the central station, counter 12 — the number of lost rates due to buffer overflow.

Thus, the device allows bo; Gay to accurately model real data transmission systems with a star-shaped structure by taking into account the possibility of retransmission of data in case of not receiving a receipt of reception results.

Claims (1)

Invention Formula A device for simulating data transmission systems, comprising a generator of a random stream of transmitted message pulses and a group of information transmission simulation channels, each of which contains a series-connected random noise generator for transmitting messages, the first element NOT and the first element AND, a series-connected random noise generator for interference transfer of receipts, the second element is NOT, and the second element is AND, the other input of which is connected to the output of the first element AND, characterized by that, in order to extend the functionality by simulating the re-transmission of messages in case of not receiving receipts on the reception results, each channel for simulating the transmission of information further comprises a clock generator, a reversible length counter five 0 message queues, message retry time counter, two OR elements, two flip-flops and from the third to ninth AND elements, and the output of the second And element is connected to the setup input of the message retry time counter on each data transmission simulation channel clock generator, direct input of the third element And and direct 0 inputs of the fourth and fifth elements And, the output of the third element And is connected to the single input of the first trigger, the direct output of which is connected to the inverse input of the common element And and the first input of the seventh And element, the output of which is connected to the single input of the second trigger, direct input of the eighth AND element and the first input of the NII element, the output of which is the output of the information transmission simulation channel, the zero input of the first trigger is connected to the output of the AND signal and the first input of the first OR element, the output which is connected to the first input of the second element OR and the start input of the clock pulse generator, the output of which is connected to the counting input of the message transmission time counter, the overflow output of which is connected to the second input of the second OR element, the output of which is connected to another input of the first AND element, output n of the element And is connected to the subtracting input of the reversible counter of the length of the queue of transmitted messages, the overflow output of which is connected to the second input of the ninth element AND and the inverse at the eighth AND gate, whose output is connected to a summing input of down counter transmitted messages queue, the output of which zeroing is connected to the zero input of the second flip-flop, a direct output of which is connected to the second input of the fifth AND gate, an inverted 0 input of the third element And and sec) 1m input of the fourth element And, the output of which is connected to the second input of the first element OR, the output of the generator of a random stream of impulses of transmitted messages of connections with the direct inputs of the smart elements And and the second inputs of the seventh elements And of all channels of information transmission modeling . five 0 five five "about Ni t QO