SU1668980A1 - Device for interfacing computer with communication channel - Google Patents

Abstract

The invention relates to telemechanics, data transmission of local computing systems. The device provides a reduction in the transmission time of service commands when organizing the exchange of discrete messages between a number of transceivers connected to a common communication channel, due to the fact that the recipient recipient and the sender of messages are not required in the reception results information. The device contains a demodulator, modulator, blocks of clock and frame synchronization, pulse regenerator, cascade frequency divider, decoder, coding unit, receiving and transmitting information storage devices, decoders of service commands and end of message, match block, OR element, trigger, prohibition block and timer. 2 Il.

Description

The invention relates to communications and can be used in automated process control systems, remote control systems, data transmission equipment, in local computing systems.

The aim of the invention is to reduce the time for the transmission of service commands.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - time diagram of the device.

FIG. 2 The following notation is accepted: F.SAI - phasing, service, address and informational signs of the message; KS, K - combinations of end-of-message and service command signs; №№ - numbers of distorted characters. Receiving commands: a - Repeat all messages; b - Repeat the distorted part of the message; c - Message Receipts; g - command formation. Message not transmitted.

The device contains a demodulator 1, a regenerator 2 pulses, a decoder 3, a clock generator 4, a block of clock 5 and cyclic 6 synchronization, a cascade divider 7 frequency, a computer 8 consumer, receiving 9 and transmitting 10 drives, encoding unit 11, modulator 12, decoders end of message 13 and service commands 14, comparison block 15, element OR 16, prohibition block 17, trigger 18 and timer 19.

The device, when used as part of a discrete message transmission system using correction codes for exchanging codograms between a number of transceivers connected to a common communication channel, works as follows.

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A customer-generated codogram with the necessary service characters, sender and recipient addresses is stored in the transmitting storage device 10 and, in accordance with the accepted exchange procedure, is transmitted through the coding unit 11 and the modulator 12 to the communication channel.

When the sign of the end of the message is selected by the decoder 13, its output signal is fed to the input of block 17 and acts on the setup input of the trigger 18, translating it into a state in which the output signal of the trigger 18 arriving on the sync-stroke of block 15 permits the latter to a timer 19, a pass to the computer 8 of the consumer and to the element OR 16 output signals of the decoder 14 service commands. The output signal of the decoder 13 also sets in the beginning of the countdown timer 19.

This order of preparation for the subsequent operation of the decoder 14 provides the necessary conditions for the transfer of service commands by the recipient of the message about the results of its reception to the sender without adding the addressee and sender of the message to the sender.

The device provides reception, generation and execution of the following service commands: Repeat the transfer of the entire message if there are distorted characters in the received message more than the limit norm; Repeat the transmission of corrupted message characters when the number of corrupted characters in the received message is less than the boundary norm; A receipt for receiving a message when receiving a complete message or completing the process of accumulating the entire message by its recipient; The message is not transmitted if it does not receive any of the listed commands at the specified time interval.

The listed capabilities of the receiver are realized with the following elements.

When the message is received by the recipient, the service commands are transmitted to the demodulator 1 via the communication channel, then to the regenerator 2 pulses and then to the decoder 3, which checks the accuracy of the commands received in accordance with the accepted decoding algorithm. In the absence of distortion, the received combinations of commands from the output of the decoding unit are fed to the inputs of the decoder 14 service commands and the receiving drive 9.

The output signals of the decoder service commands received at the information inputs of the block 15, are transmitted by him to the computer 8 consumer and to the input element OR 16 in the presence of the synchronous input unit 15 enabling signal from the output of the trigger 18.

When receiving a service command Repeat the distorted part of the message, the numbers of the distorted characters are stored in the receiving drive 9. The recording process is controlled by the consumer’s computer 8 from the moment the command is received until the selector of the receiving storage device is selected to sign the end of message.

At the end of the reception of the service command to repeat the transmission of the computer 8, the consumer issues control actions (clock pulses or numbers 9 of distorted characters transmitted from the receiver drive) to the transmitting drive 10,

which provides retransmission of the entire or corrupted part of the message.

The message transfer process is completed by receiving the Receipt Message Receipt command.

Control pulses required

for operation of blocks 2, 3, 9-11. The receivers 13, 14 and 19 are outputted by interconnected blocks of clock 5 and cyclic 6 synchronization, as well as a cascade divider 7 of frequency. The inputs of the clock synchronization unit are connected to the clock generator 4 and the demodulator 1.

If during the time determined by timer 19, no commands are accepted

repetition of the transmission or receipt of the output signal of the timer 19 returns the trigger 18 to the initial state and resets the prohibition block 17, which, due to the absence of the inhibit signal from the output of the OR element 16, forms the command Information not transmitted. At this command, the computer 8, the consumer stops sending the message to the given consumer until the reason for the communication violation is found.

In the device, service commands about the results of receiving messages do not contain address characters (code combinations of numbers) of the recipient and the message sender, which reduces the transmission time of commands and the message as a whole.

Claims (1)

Claims A common-link computer interface device comprising a demodulator, whose input is an input to a device for connecting to a common communication channel, the output of the demodulator is connected to the information inputs of the pulse regenerator and the clock synchronization unit. the synchronous input of which is connected to the output of the clock generator, the first output of the clock synchronization unit is connected to the synchronous inputs of the pulse regenerator, decoder, frame synchronization unit, with the first gate input of the cascade frequency divider, the first output of which is connected to the gate inputs of the decoder, the decoder of service commands and the receiver drive whose synchronous input is connected with the second output of the clock synchronization unit, with the second gate input of the cascade frequency divider and with the synchronous inputs of the transmitting one the accumulator and the coding block, the output of which is connected to the information input of the modulator, the output of which is the output of the device for connecting to the common communication channel, the output of the pulse regenerator is connected to the information inputs of the frame synchronization block and the decoder whose output is connected to the information inputs of the receiver the accumulator and the decoder of the service commands, the output of the frame synchronization block — with the synchronous input of the cascade frequency divider, the output of the receiving accumulator is the output of the device for and to the input of computer data. the second output of the cascade frequency divider is connected to the gate The inputs of the decoder of the message end, the coding block and the transmitting accumulator, whose information input is the information input of the device for connecting to the computer data output, the output of the transmitting accumulator is connected to the information inputs of the encoding block and the end of the message decoder, characterized in that, in order to shorten the time transmission of service commands, a timer, a comparison unit, a prohibition block, an OR element and a trigger, whose output is connected to the synchronous input of the comparison block, an information input, are entered into it is connected to the output of the service command decoder, the output of the message end decoder is connected to the setup inputs of the inhibit block, timer and trigger, the reset input of which is connected to the timer output and the reset input of the inhibit block, the information input of the inhibit block is connected to the output of the OR element, whose inputs are connected to the outputs of the comparison unit, which are the control outputs of the device for connecting to a computer, the output of the prohibition unit is the output of the device for connection to the input Restarting the computer, and the second output One cascade frequency divider is connected to the counting timer input. Yu 13 18 15 П 19