SU1524187A1 - Transceiver for multiple-access network - Google Patents

Abstract

The invention relates to a data transmission technique. The purpose of the invention is to improve the reliability of the multiple access network. The device contains an interface unit 1, a communication line 2, a terminal 3, a terminal station 4, an interface receiver 5, a channel transmitter 6, an amplifier 7, detectors 8 and 21, triggers 9.22 and 29, timers 10-14, and elements OR 15- 17, channel receiver 18, switches 19 and 20, conflict indicators 23 and 24, interface transmitters 25 and 26, element 27 and r-28. When the power is turned on, interface unit 1 is set to "loopback" mode, allowing it to be tested block, did not carry out the transfer of information to the communication line 2. Then the authorization of work is carried out the interface unit 1 to a communication line 2. In the "reception of information from link 2" are two possible cases: "correct reception" and "reception at a conflict situation in line." When transmitting to communication line 2, the following cases are possible: "transmission - reception correctly", "conflict in the block", "conflict in the line - the last", "conflict in the line - not the last" and "station generation". 1 il.

Description

and 29, timers 10-14, el-OR 15-17, channel npHeNfHHK 18, switches 19 and 20, conflict indicators 23 and 24, interface transmitters 25 and 26, el-27 And 27 Mr. r. 28. When enabled power supply interface unit 1 is set to the Loop mode, which allows to check the performance of this unit, did not transmit information to the communication line 2, then the resolution is

bots of the interface unit 1 with a communication line 2, In the mode of receiving information from communication line 2, two cases are possible: Correct reception and reception in case of a conflict situation in the line. When transmitting to communication line 2, the following cases are possible: Transmission — reception is correct, Conflict in the block, Line conflict — last, Line conflict — not last, and Station generation. 1 il.

The invention relates to the field of data transmission and can be used in mono-channel local computing. multiple access networks.

The purpose of the invention is to improve the reliability of the multiple access network.

The drawing shows the block diagram of the device.

The device contains an interface unit 1, a communication line 2, a terminal 3, a terminal station 4, an interface

receiver 5, transmitter 6, amplifier 7, first detector B,

the first trigger 9, the first 10, the second 11, the third 12, the fourth 13 and the fifth 14 timers, the first 15, the second 16 and the third 17 OR elements, the channel receiver 18, the first i9 and the second 20 switches, the second detector 21, the second trigger 22 , the first 23 and second 24 conflict indicators, the first 25 and second 26 interface transmitters, the element And 27, the generator 28 and the third trigger 29.

The device works as follows.

When the power is turned on, block 1 is set to loop mode, i.e. in a mode that allows you to check the operability of the interface unit 1, did not transfer information to the communication line 2. At this MO, the output of the first detector 8, trigger 9, timers 10 and 11, the first and second outputs of timers 12-14, the first and second outputs of the second detector 21, high logic levels are set at the output of trigger 29, 22 and indicator 24 - low logic

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levels, the first output of the indicator 23 is set to a high logic level, the second output of the indicator 23 - a low logic level. Setting a high logic level at the first output of the indicator 23 triggers the start of timer 13 through the element OR 16n setting the second output of the timer 13 to a low logic level, which allows transmitting to the additional input of station 4 a signal confirming the activation of the interface unit 1. Setting the high logic level at the output of the trigger 29 leads to connecting the output of the amplifier 7 to the first input of the interface transmitter 25 and the input of the second detector 21 through the switch 19 on one side and blocking the channel transmitter 6 through the element OR 15 on the other (high logic level at the third input of the channel transmitter 6).

In the Speff mode, the information sequence from the output of station 4 is fed to the input of the interface receiver 5. From the first output of the interface receiver 5 received from station 4, information is fed to the first input of the channel transmitter 6 and the input of the amplifier 7, from the second output of the interface receiver 5 to the input of the first detector 8; the first detector 8 selects the envelope of the information packet and sets at its output a signal to the Low log level which goes to the first input of the trigger 9 and the second inputs of the indicators 23 and 24. At this moment, a high logic level is set at the second input of trigger 9.

All these conditions lead to the appearance at the output of the trigger 9 of a low logic level signal that arrives at the first inputs of the timer 10, the OR 15 element and the indicator 24. At the same time, the output of the OR 15 element does not change its state, since at the second input element 15 is set to a high logic level from the output of trigger 29. The indicator 24 of its state does not change. Setting a high logic level allows connecting the output of amplifier 7 to the input of the second detector 21 and the second input of the interface transmitter 25. This results in setting the first output of the second detector 21 of the signal to receive a low logic level and transmitting it to the second input of timer 11 and the first inputs of the indicator 23 and interface transmitter 25. Setting the Receive signal triggers timer 11 and enables the operation of interface transmitter 25, i.e. allows to transmit the received information to the input of station 4. Changing the state of the output of timer 11 does not affect the state of the output of trigger 9. At the end of the transmission, i.e. when removing the information sequence from the output of station 4, similarly to that described, from the first input of trigger 9 and the first input of detector 21, the Transmit and Receive signals are removed, respectively. This triggers the indicator 23 and the installation at its first and second outputs of low and high logic levels, respectively, which leads to the installation of low and high logic levels at the outputs of the OR 16 and 17 elements, respectively. The timer 14 is triggered and the pulses generated by the generator 28 are allowed to pass through the switch 20 to the input of the interface transmitter 26, from the output of which these pulses come

to the additional entrance of station 4, identifying the conflict situation in the line. After the timer 14 triggers, a high logic level signal is set at its second output, a negative field pulse is generated at the first output, which triggers the And 27 element and trips the indicator 23, i.e. installation

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low logical levels or its Jii.i- moves. The installation of the high logic level switch on the fourth pxciAe 20 leads to the cessation of the transmission of pulses from the generator output 28 to the additional input of station 4 and triggers the trigger 29, the device operation mode is set at which the unit is enabled

1 with line 2 connection.

In the mode of Receiving information from line 2 of communication, two cases are possible: Correct reception and Reception in case of a conflict situation in the line. In the case of correct reception, information from line 2 is fed to channel receiver 18, the output of which goes to the third input of the switch 19 and then to the input of the second detector 21 and the first input of the interface transmitter 25. Similarly to reception in 1Mleyf mode on the First output of the second detector 21 a low logic level sets a signal that Leads to the Transmission to the input of station 4 of the information sequence received by the interface unit 1 from the communication line 2. At the end of reception from line 2, the reception signal is removed, which leads to the operation of the indicator 23, the installation of the high-level signal on the first input and the start of the timer 14, i.e. Station 4 is notified of the end of the receive line operation.

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In the Receive mode from line 2 communication in a conflict situation, i.e. if there are two or more transmissions at the same time, a second logic level is set at the second output of the second detector 21, which is fed to the counting input of the trigger 22, which leads to a high logic level signal at its output and, through element 16, to start the timer 13. This causes the transmission to the auxiliary input of station 4 of such a number of pulses produced by the generator 28, which corresponds to the response time of timer 13. After the completion of the operation of timer 13, an output pulse is generated at its output polarity, which sets the output of the trigger 22 low logic level, i.e. confirms through the scheme

27 installation at the indicator outputs 23 low-level signals. Disconnecting a signal Reception from the first output of the detector 21 after resolving a conflict situation causes the timer 14 to start and the station 4 to alert.

When transmitting to line 2, the following cases are possible: Transmission — reception is correct, Block conflict, Line conflict — last, Line conflict — not last, and Station generation.

R case of situation Transmission - reception of correct information from station 4 arrives at the interface receiver 5, from the outputs of which is fed to the first input of the channel transmitter 6 and the input of the first detector 8. At the output of the detector 8 a signal is set Transmit low logic level, which triggers the trigger 9 and installation at its output and output of the element 5 low logic level signals. At the same time, the operation of channel transmitter 6 and information transmitted by station 4 is allowed to enter line 2 of communication, from where via channel receiver 18 and switch 19 it enters the input of the second detector 21 and the second input of interface transmitter 25. Next, unit 1 behaves Similar to the situation. Correct reception with the only difference is that when the transmission is stopped in the high logic level setting, the second output of the indicator 23 uses the analysis of the Transmit and Receive signals, after which the timer 14 starts and the station 4 is alerted.

Situation A block conflict occurs under the following conditions: station 4 began transmission, but this transmission has not yet been placed on link 2; Information is already coming from line 2 to block 1. Transmitted by another station. Otherwise, if the Reception signal is established with some leading advance in relation to the Transmit signal (the situation is opposite to the Transmit – Reception case correctly), i.e., if the low logic level signal at the second input of the trigger 9 is set before the low logic signal at its first input The trigger state 9 is not

changes and at its output there is a high logic level, the channel transmitter 6 is blocked. Such a combination of signals is analyzed by the indicator 24, which leads to the installation of a high logic level signal at its output and, through element 17, to start the timer 14, i.e. Alert station 4. Station 4 in accordance with the conflict resolution protocol stops transmitting. Block 1 is in the Acquire InLormation mode from line 2. Timer 11 is needed to automatically disable the priority function of receiving from line 2 over the transmission of station 4, i.e. the priority function is set to a time that slightly exceeds the processing time by station 4 of the conflict situation. This makes it possible for station 4, if it is impossible to receive an information packet arriving in a non-link 2, to provoke a conflict in link 2, i.e. use the mechanism of protection against the loss of packets in the event of an overload of station 4 receiving buffers.

Situations Line Conflict — the last and Line Conflict — not the last differ only among themselves by endings and are processed by block 1 as follows. The transmission to line 2 of communication occurs in the same way as in the case of Transmission - Reception - correctly, but a conflict situation occurs on line 2, which is detected by the second detector 21 and is processed similarly to the situation. Reception during a conflict situation in the line. At the end of the situations under consideration, the removal of the signal is transmitted. Transmission from the detector output 8 and Reception from the detector output 21 and depending on the conditions of Simultaneous or Transmission removed, respectively, the second or first outputs of indicator 23 are set to a high logic level, which leads to a trigger. timer 14 or timer 13; otherwise, it corresponds to the station 4's skinny alert. The exit condition last of a conflict situation indicates that station 4 began transmitting first and, having the appropriate means PRIOR tim output NOSTA can enjoy using the notification transmitted to it for polu9

benefits from the next attempt to transfer to link 2.

Situation Generation station can occur due to failures in the output nodes of station 4, using the means of presenting the transmitted information using Manchester coding and in case of violation, namely, exceeding the maximum specified size of the information packet. Block 1 handles this situation similarly to the situation. Transmission - reception is correct, but setting a low logic level at the output of trigger 9 not only enables the channel transmitter 6 to work, but also starts timer 10. If the signal duration is less than a specified number of bit intervals, then Signal Transmission automatically resets Timer 10 and no signals are generated at its output, i.e. If the duration of the Transmit signal exceeds this number of bit intervals, the output of timer 10 is set to a low logic level, which is fed to the second input of the channel transmitter 6, which causes it to block and stop transmitting to link 2, and on the first inputs of timer 12 and switch 20. Timer 12 starts up and at its second output a low logic level signal is set, which allows Transmit Station 4 alerts. After the expiration of the response time of timer 12, a pulse of negative polarity appears at its first output, arriving at the first input of trigger 29, which causes it to trigger, i.e. transfer of block 1 to the mode 01leif. Setting a low logic level at the fourth input of unit 23 does not allow it to operate and view unit 1 of the Loop mode in the event that the station is stopped.

Claims (1)

Invention Formula  A transceiver device for a multiple access network comprising a communication link, a terminal station, a serially connected interface receiver and a channel d 20 25 30 35 0 5 0 five 1Я7 10 the transmitter, the first detector, the first trigger and the first timer, the channel receiver, the second detector, the first interface transmitter and the generator, the second output of the interface receiver connected to the input of the first detector, the output of the first timer connected to the second input of the channel transmitter, the first output of the second, the detector is connected to the first input of the first interface transmitter, the input of the interface receiver and the output of the nepjBoro interface to the transmitter are connected respectively to the output and the input of the channel station and the channel transmitter output and the channel receiver input are connected to a communication line, characterized in that, in order to improve the reliability of the multiple access network, an amplifier, first, second and third elements OR, second, third, fourth and fifth are introduced timers, first and second switches, second interface transmitter, second and third triggers, first and second conflict indicators and elements, And, the amplifier input is connected to the first output of the interface receiver, the amplifier output is connected to the first input The first switch, the output of the first element OR is connected to the third input of the channel transmitter, and its first input is combined with the first input of the second conflict indicator and connected to the output of the first trigger, the second input of the first OR element and the second input of the first switch are connected and connected to the output of the third trigger, the third input of the first switch is connected to the output of the channel receiver, the output of the first switch is connected to the input of the second detector and the second input of the First interface transmitter. The first inputs of the second, third, fourth and fifth timers are connected to the second input of the First timer and the First input of the second switch and connected to the output of the generator, the second input of the second timer is connected to the first input of the first conflict indicator and connected to the first output of the second detector, the output of the second timer connected to the second input of the first trigger, the second output of the second detector connect. 1115 with the counting input of the second trigger, the setup input of which is connected to the first input of the AND element and connected to the first output of the fourth timer, the second output of which is connected to the second input of the second switch, the output of the second trigger is connected to the first input of the second OR element, the output of which is connected to the second the fourth timer input, the second input of the second OR element is connected to the first output of the first conflict indicator, and its second output is connected to the first input of the third OR element, the output of which is connected to the second fifth entry in the timer, the second input of the third OR gate connected to the output of the second indicator conflict, conflict second inputs of both indicators are combined and connected to the output of the first detector, the third input of the first indi712 A conflict is connected to the output of the element I, the second input of which is combined with the installation input of the third trigger and connected to the first output of the third timer, the third input of the second switch and the second input of the third timer are combined with the fourth input of the first conflict indicator and connected to the output of the first timer, the third inputs element And the second conflict indicator is connected to the first output of the nth timer, the second output of which is connected to the counting input of the third trigger and connected to the fourth input of the second switch ora, the output of which via a second interface transmitter connected to an additional input terminal stations, fifth input of the second switch is connected to the second output of the third timer.