SU1587526A1 - Device for interfacing segments of common communication line - Google Patents

Abstract

The invention relates to computing and can be used to communicate computers in multi-segment local area networks. The purpose of the invention is to increase the reliability of data exchange. The goal is achieved by introducing into a device containing two matching units, two transmitters, two receivers, a switch, a conflict highlighting unit, two segment state analysis units, two pulse generators. 1 s., 2 s. P. f-ly, 5 ill.

Description

one

(21) 4331377 / 24-24

(22) 11/23/87

(46) 08.23.90. Bul No. 31

(71) Perm Scientific Production Association PARMA

(72) E.V. Kayushev, V.I. Kiselev, N.I. Artyomov, V.A. Vaskin, V.N. Popov and A.A. Wolves

(53) 681.325 (088.8)

(56) USSR author's certificate

IP 1283742, cl. G 06 F 13/00, 1985.

USSR Author's Certificate No. 1499361, cl. G 06 F 13/14, 1986.

(54) DEVICE TO CONNECTION OF THE SEGMENTS OF THE EXPAND COMMUNICATION LINE

(57) The invention relates to computing and can be used to communicate computers in multi-segment local area networks. The purpose of the invention is to increase the reliability of data exchange. The goal is achieved by introducing a device containing two matching units, two transmitters, two receivers, a switch, a conflict block, two segment state analysis blocks, two pulse generators. 2 hp f-ly, 5 ill. Q

. S

The invention relates to computing and can be used in local multi-segment computing networks.

The purpose of the invention is to increase the reliability of data exchange.

FIG. 1 is a block diagram of the device; in fig. 2 and 3 are functional diagrams of the block of conflict and the block of analysis of the state of the segment; in fig. 4 and 5 are the time diagrams of the operation of the block of the configuration of the konfikt and the device.

The device (Fig. 1) contains the first 1 and second 2 matching blocks, the first 3 and second 4 transmitters, the first 5 and second 6 receivers, the block 7 of the conflict, the first 8 and second 9 blocks of the segment state analysis, the first 10 and second 11 pulse generators, switch 12.

Block 7 in the conflict gap contains (Fig. 2) the element EXCLUSIVE OR 13, trigger 14, the first 15 and the second 16 one-shot.

Blocks 8 and 9 of the segment state analysis (Fig. 3) contain a trigger 17, a one-shot 18, an element AND 19 and an element OR 20.

The drawings show lines 21-34 of the connections between the units of the device. Matching blocks 1 and 2 (Fig. 1) are designed to match the electrical parameters of communication lines and can be made either as a resistive divider, or as a matching transformer, or as an exact resistor with a nominal equal to the characteristic impedance of the communication line. Depending on the purpose of the system in which the proposed device is used.

D1

Block 7 is designed to detect the fact of simultaneous transmission of other / devices on adjacent segments of a common line connected by a device. Blocks 8 and 9 are used to analyze the direction of information transfer, to exclude racing situations in the circuit, to restore the electrical parameters of the attenuated signal in the communication line,

The device works as follows.

At the initial moment of time there is no transmitted information in the segments of the communication line. At the outputs of the first 5 and second 6 receivers there is a constant level of logic O, which is also present at the outputs of blocks 8 and 9, as well as

the outputs of the switch 12. The level of the log-2o is similar, since the device of the full O from the second outputs of blocks 8 and 9 keeps the second 4 and the first 3 transmitters off in the control inputs, respectively.

Active devices capable of exchanging information on segments of the communication line on their own initiative can be connected to any of the two segments adjacent to the device.

symmetry.

In the case of simultaneous transmissions in two segments associated with a device, block 7 continuously compares (taking into account delays in the device) information received from one segment with information that is transmitted to an adjacent segment. In the case when in the adjacent segment which

When a B mo6oj transmission occurs (sometime the source at the same moment

time, the information is transmitted; on the corresponding block 1 or 2 matching, the transmission will overlap, and hence the signals will be distorted, i.e. conflict. Conflict will be detected by block 7 and the output of block 7 will be set to logic level 1 for the time

35

40

from the segments at the corresponding input-output device of the device, according to a string, a pulse sequence of electrical signals. Suppose, for example, that such a sequence arrived at the first input-output device. In this case, at the output of the first receiver 5, the pulse sequence also appears, completely corresponding to the sequence sequence in the first segment of the communication line. The functions of the receiver in this device are to convert the signal feature of the received signal to a form convenient for further processing (for example, 45 to TTL levels), to amplify and limit the signal, etc.

The received sequence of pulses is then processed by block B, whose functions include: recovering the electrical parameters of the received signal, determining the presence of transmission on the communication line, and determining the direction of transmission of information. At the second output of the block 8, the signal with a logic level of 1, which is. will allow the transmitter 4 to work, and also blocks block 9 on the input, preventing possible self-excitation

devices and excluding racing work schemes.

The recovered pulse, the output sequence of the block 8 then goes to the input of the switch 12 and then appears at the second output of the switch 12, at the information input of the switched on transmitter 14 and through the matching unit 2 after amplification and conversion by the transmitter 4 to the form suitable for transmission in the adjacent segment.

At the end of the transmitted pulse sequence, the device returns to its original state.

When a similar sequence of pulses arrives at the second input-output device will work

similarly, since the device is

symmetry.

In the case of simultaneous transmissions in two segments matched by a device, block 7 continuously compares (taking into account delays in the device) information received from one segment with information that is transmitted to an adjacent segment. In the case when in the adjacent segment which

sometime source at the same moment

time, the information is transmitted; on the corresponding block 1 or 2 of matching, transmissions will overlap, and hence the signals will be distorted, i.e. conflict. The conflict will be detected by block 7 and the outputs of block 7 will be set to logic level 1 at the time

where t is the time for which the signal is set at the first output of the conflict separator 7;

t, is the time for which the signal is set at the second output of the conflict separator 7.

These times are selected depending on the so-called round-trip time, i.e. from total signal propagation delays in communication lines and in similar devices (if there are several of them).

In this case, the first 3 and second 4 transmitters are forcibly switched on by the action of a single signal at their control input coming from

ten

15

forcibly set at time t to one state the second outputs of blocks 8 and 9. At time t switches 12 on the control input and the pulse sequence from the pulse generator 11 goes to the first and second outputs of the switch 12, and then through the first 3 and second 4 transmitters and through the first 1 and second 2 blocks of matching to the device inputs-outputs and to the communication line segments. This will lead to increased conflict in the segments, and to its spread and, ultimately, to the strengthening of its other similar devices of the communication line.

The conflict isolation unit 7 (Figures 2, 4) operates in the following manner. The inputs of block 7 are supplied with the signal-output outputs of the device for sub-terminals from the second inputs-outputs of the first part to the first and second segments 1 and the second 2 matching blocks. In general, the second line of communication, and the second information about the coincidence of the pulse sequential inputs-outputs are connected respectively to the inputs of the element EXCLUSIVELY with the inputs of the first and second LEDs OR 13, which corresponds to the free receivers and outputs of the first and conflicting operation of the device, to Second transmitter, allocation unit

the output will remain the log-conflict level, the first output of connection O. Information from the output is ele-ny with the control input of the switch,

EXCLUSIVE OR 13 is supplied to the first and second outputs of which the D-input of the trigger 14 and is controlled so that the SO will be transmitted to the output of the block, as the inverse input of the element 19 is present. logical 1 from block 7, trigger 17 is reset to the state of logical O, which prohibits production of information at the output of the block and leads to the forced setting of the level of logical 1 at the output of the OR 20 element.

Claims (3)

Invention Formula ,,one. A device for conjugation of common communication line segments containing the first and second matching blocks, the first information inputs / outputs of which are corresponding to the reference frequency from generator 10 for eliminating false triggering of block 7. When imposing information transmissions on the inputs of the EXCLUSIVE OR element 13, do not match will result in the trigger 14 being set to one state, triggered by a signal from the trigger output of the first 15 and the second 16 one-shot, which in turn will lead to the appearance of logic 1 at the first and second outputs of block 7 for conflict resolution, respectively, at time t. and t-. The blocks 8 and 9 of the analysis of the state of the segment (Fig. 3) operate as follows. The received information is supplied to the D input of the trigger 17, and the capacitor is built by the generator pulses 10 for improving the shape of the fronts processed by the 50 input block selection conflict and pulse sequence. Upon the arrival of the first pulse, a restartable one-shot 13 will operate both at its output and at the output of the element OR 20 the level of the logical unit of the block of the conflict is set, the first Those that are stored there until not yet. And the second informational inputs are finally receiving and transmitting it all, respectively, with a second-pulse sequence, which informational inputs-outputs from the output of trigger 17 through the element of the first and second matching blocks, 0 five 0 dam-outputs of the device for connecting to the first and second segments of the common communication line, and the second information 19 is transmitted to the output of the block, since the inverse input of the element 19 is present. Allowing level of logic O is present. Block 7, the trigger 17 is reset to the state of logical O, which prohibits the display of information at the output of the block and leads to the forced setting of the level of logical 1 at the output of the element OR 20. Invention Formula ,,one. A device for interfacing common network link segments, containing the first and second matching blocks, the first information inputs / outputs of which are the corresponding inputs 5 five 0 The first and second information inputs, respectively, with the first outputs of the first and second segment analysis units, the second outputs of which are connected respectively to the control inputs of the second and first transmitters and the blocking inputs of the second and first blocks, analysis segment state, the outputs of the first and second receivers are connected respectively to the information inputs of the first and second segment state analysis blocks, differing in that, in order to increase the fidelity of data exchange, the first and second pulse generators are entered into the device, with the output of the first pulse generator connected to the clock the synchronization inputs of the first and second segment state analysis blocks, the enabling inputs of which are connected respectively to the second output of the second generator. The pulses are connected to the third information input of the switch, 2. Device pop. 1, which differs in that the conflict selection block contains a trigger, the sync input of which is the clock input of the block, an EXCLUSIVE OR element, the first and second inputs of which are the first and second information inputs of the block, and two single-vibrator which are, respectively, the first and second outputs of the block, and the output of the element EXTINGUISHING OR is connected to the information of the 5 trigger input, the output of which is connected to the inputs of the first and second one-shot. 3. The device according to claim 1, 1 and 2, in that the segment state analysis block contains a trigger, whose information input and synchronous input are respectively the information and synchronization inputs of the block, the AND element and the OR element, the outputs which are, respectively, the first and second drives of the block, and the one-oscillator, with the reset trigger input connected to the enable input, the block and the first input of the OR element, the second input of which is connected to the trigger output and the direct input of the AND element, inverse the entrance to which This is the block lock input. 1 d.2 Normal work FIG. -1 p p gi-i g 91 / g. 4 " BfodlboKl. BxodldbixZshplpgigllllll-tl 5