SU1381520A1 - Multichannel device for connecting subscribers to trunk line - Google Patents

Abstract

The invention relates to computing and is intended for use in local data networks. The purpose of the invention is to increase the fault tolerance of the device due to the fact that it eliminates blocking situations in any possible interference situations while reducing hardware costs. To achieve this goal, each channel 1 of the device, containing receiving 3 and transmitting 11 amplifiers, element AND 7, first 5 and second 10 triggers, delay element 6, introduced two elements OR 8 and 9. The interference effect is greatly attenuated for the packet in whole or in general is excluded for the preamble of the packet due to the permanent confirmation of the state of the triggers 5 and 10 by signals "1 transmitted (received) packets in the process of their transmission (reception) and restoration of the states of the triggers 5, 10 corresponding to one of the initial operation modes of channels 1 (transmission or reception). The use of the delay element 6 makes it possible to completely eliminate the appearance of signals that are truncated in duration at the output of element 7 in transient modes of switching channels 1 from reception to transmission. This provides the possibility of eliminating complete locks, suppressively reducing the number of corrupted packets and improving the reliability of the device. 2 Il. 1 (L

Description

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The invention relates to computing and can be used in local networks of computers.

The aim of the invention is to improve the fault tolerance and reduce the hardware costs of the device.

FIG. 1 is a block diagram of the device; in fig. 2 - timing charts of the device.

The device in each of its channels (interface) 1 contains a trunk (central i1inu) 2, a mu amplifier (receiver) 3. line 4 of the information input of the channel, trigger 5, delay element 6, element AND 7, elements OR 8 and 9, trigger 10, the transmitting amplifier (transmitter) II, the channel 12 information output channel.

The device is directly intended for receiving packets of information arriving via lines 4 of interface 1, arbitrating a packet arriving first, switching it to Ton 2, and transmitting on line 12 through transmitting amplifiers of interfaces I.

The functions of subscriber stations that receive (transmit) data through the device are the same for all stations.

The device works as follows.

From subscriber stations, on lines 4, through amplifiers 3, random signals are received from transmitted packets containing a preamble. The preamble signals are a sequence of alternating ones and zeros (101010 ...). The duration of the “1” and “O preamble” signals is the same and is equal to the half-period of the transmission frequency of the coded signals in the packet.

The previously received signal I of the preamble of a subscriber station arrives first through element 6 to the inputs of the AND 7, OR 8 and 9 elements and sets the trigger 5 to the state 1. The magnitude of the time delay of element 6 is limited by the minimum to the sum of the resolution time of the trigger 5 and the delay of OR 8, and the maximum value of the duration of the signal "1 in the preamble.

Simultaneously, the preamble signal enters through the OR 9 element at the counting input of trigger 10 and sets at its output “O, since the signal on pin 2 is missing. After the trigger 5 is installed, the signal “1” from its output goes to the reset input of the trigger 10.

After trigger 5 is set to “1, the signal“ I of the preamble passes through the element I 7 to the level 2. In the interface I, to which the preamble signal from the subscriber station arrived before others, the action of the signal “1 preamble from the level 2 is blocked, since his mentality

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The signal "1 preamble from the output of amplifier 3 is still valid. This is always ensured if the duration of the signal" 1 preamble is greater than the delay of its propagation to 5 of 2. As a result, the trigger 5 of this interface 1 remains in the state "1 and the signal from its output holds the trigger 10 at the reset input in the state “O.

In interfaces 1, where the signals of the "1 preamble" arrive at the information input of the trigger 5 later or simultaneously with the signals of the "1 of Tina 2", the trigger 5 through the OR element 8 is set at the counting input of the "O. The trigger 10, at the input of which the signal "1 second 2, acts through

The 15 element OR 9 is set with this signal to "1. In this case, the delay introduced by the element OR 9 is purposefully used to ensure that the signal "1 on the synchronous input of the trigger 10 is clamped later than on the information input. Signal "1

20 from the trigger output 10 operates on the input of the element OR 8, confirming the installation of the trigger 5 in the “O. As a result, the signals from the output of the amplitude. T 3 do not pass through the blocked element And 7.

25 Thus, the transmission of a packet through all interfaces, in addition to which the preamble signal arrived first, is blocked.

The subscriber station receives information on the results of successful transfer of a torture by transferring the address of a packet received from line 12 with the address of a packet transmitted on line 4. The coincidence of these addresses means that an attempt to transmit ycneujHa and the subscriber station implements broadcasting for 35 of all others. If the addresses of the subscriber station do not match, the subscriber station waits for the data transfer device to be released (the transmission ends of the other subscriber station) and retries the transmission attempt.

In case of arbitrary failures of triggers 5 and 10, the operation of interfaces 1 is always restored. Consider the situation when after installing trigger 5 in “1, it fails in“ O. Signal

The preamble 45 output element And 7 is interrupted for the duration of the interference. After its termination, the first of the signals of the "1 preamble, arriving at the information input and through the delay element 6 and the element OR 8 at the input of the trigger 5, sets it to" 1. Thus, packet transmission as a whole is restored. Suppose that simultaneously with such a failure, trigger 10 is set to state "1 instead of" O. Then, after the termination of the interference, the first of the signals "1 preamble,

5 enters through the delay element 6 and the OR element 9 at the input of the trigger 10, presets it to the state "O, and then the next of the signals" 1

Claims (1)

Claims of the Invention A multichannel device for connecting subscribers to a trunk, which in each channel receives and transmits each channel the output of the first trigger is connected to the first input of the element I. Its output is connected via the trunk from the pre-preamble to set the trigger 5 to "I. Thus, the operation of the interface is restored through the period of the accumulation of "1 preamble" signals. Overall nose length The sequence of preamble signals selects amplifiers, the element I, the first and the second so that the possible costs of backgammon triggers and the delay element, while restoring the operation of the interfaces 1, do not affect the input to the synchronism of the receiving devices of subscriber stations. house transmitting amplifier, the output of which From the diagram of FIG. 2 that the over and the input of the receiving amplifier are the corresponding output and channel input for connecting to the information inputs and outputs of the subscriber, characterized in that tactical value. mimic. —The purpose of increasing the fault-tolerant phase shift of packets for the purpose of hardware costs, two elements of I.1I packets are introduced into each cadmium arbitration of the first incoming device. In case of a false failure of the trigger 5 (the synchro-sync inputs of the first and second Hove lines), the device of the practical triggers is connected to the upper one and the first one does not break, since the first triggers OR 5 are restored by the following re-20 of which are connected to the output of the element by the signal of the packet in “1. With a single delay and a second input of the element AND a temporary false failure of the flip-flops 5 and 10, the output through the trunk is connected to the (dash-dotted line) operation of the device by the second inputs of the first and second power is no more than in the period. OR or information input of the second trigger, the output and the reset input of the device. The device is completely independent of the third one, respectively, connected to the third one from the variation of the period, since the logic input of the first OR element and the output The hold of the delayed element b may be a small fraction (unit of nanoseconds) of the duration of the ' 1 preamble signal. This value actually determines the minimum work of each interface 1 invariant to any changes in the period value and is determined only by signal transitions. the first trigger, information input connected to the output of the receiving amplifier and the input of the delay element. Claims of the Invention A multichannel device for connecting subscribers to a trunk, containing in each channel receiving and transmitting Amplifiers, an And element, first and second triggers, and a delay element, in which the transmitting amplifier, the output of which and the input of the receiving amplifier, are the corresponding output and channel input for connecting to the information inputs and outputs of the subscriber, characterized in that , with each channel, the output of the first trigger is connected to the first input of the element I. The output of which is connected via a trunk to the input amplifiers, element I, the first and second triggers and the delay element, and in the transmitting amplifier whose output and input of the receiving amplifier are corresponding output and channel input to connect to the information inputs and outputs of the subscriber, characterized in that which are connected respectively to the third - th input of the first element OR and the output the first trigger, information input connected to the output of the receiving amplifier and the input of the delay element. (rig g