SU1594539A1 - Multichannel device for priority connection of data sources to trunk line - Google Patents

Abstract

The invention relates to computer technology and can be used to interface the equipment of computer systems with a data communication line. The purpose of the invention is to increase the reliability of the device by providing guaranteed access to the exchange of data for each information source by cyclically shifting priority between channels. The device contains several channels, each channel contains a synchronization node 14, a priority analysis node 15, a trigger 16, a delay element 17, a priority transfer node 18, a block of switches 19, AND 20 element, OR element 21, two matching elements 22, 23 and element NOT 24. It is possible to implement a cyclic priority shift in the system in the device, due to which each information source in the system is guaranteed access to the data exchange highway for the next K transmissions (K is the number of channels) since the moment the request was issued by the source. 1 hp f-ly, 6 ill.

Description

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Information KiPochnik FIG. 2

The invention relates to computer technology and can be used to interface the equipment of computer systems with a data communication line.

The aim of the invention is to increase the reliability of the device by providing guaranteed access to the exchange of data to each information source by cyclically shifting the priority between channels.

FIG. I shows the block diagram of the device; in fig. 2 is a block diagram of one channel; in fig. 3 - synchronization node; in fig. 4 - the same, priority analysis; in fig. 5 - the same, priority transmission; in fig. 6 - switch unit.

The multichannel device for priority connection of information sources to the trunk (Fig. 1) contains the first, second and last channels 1-3, device inhibit outputs 4, device 5 inputs and device polling outputs 6, device 7 inputs and output 8 outputs of the device, control outputs 9 channels, device request inputs 10, device reset inputs 11, device exchange enable outputs 12, and inputs 13 of the initial device setup.

The channel (FIG. 2) contains a synchronization node 4, a priority analysis node 15, a trigger 16, a delay element 17, a priority transmission node 8, a switch block 19, AND elements 20, an OR element 21, matching elements 22 and 23, a HE element 24.

The synchronization node (Fig. 3) contains the element And 25, the trigger 26, the element OR 27, the first, second, third and fourth inputs 28-31 of the node, the first and second outputs 32 and 33 of the node.

Node 15 analysis of priority (Fig. 4) contains the elements And 34 and 35, the elements NOT 36 and 37, the first and second outputs 38 and 39 of the node, the first, second and third inputs 40-42 of the node.

The priority transfer node 18 (FIG. 5) contains a two-stage trigger 43, a HE element 44, a delay element 45, first, second, third and fourth inputs 46-49 of the node, first 50 and second 51 outputs of the node.

The switch block (Fig. 6) contains the first and second switches 52 and 53, the first, second, third and fourth outputs 54-57 of the node, the first, second, third and fourth inputs 58-61 of the node.

The device works as follows.

When power is supplied in each channel, the trigger 26 of the synchronization node 14 and the trigger 16 are reset to the initial (zero) state via the reset input 11, as well as the two-stage trigger 43 of node 18

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five

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transfer priority through the input 13 of the initial installation from the corresponding source of information. The first and second switches 52 and 53 of block 19, when energized, switch to the signal transmission state from input B to output (in the absence of power, these switches are in the signal transmission state from input A to output, Fig. 6). The use of the node to connect to the trunk in each channel allows the device to remain operable when power is disconnected in any channel by switching the polling input 5 directly to the polling output 6 through the first switch 52 of block 19, as well as the transmission priority input 7 directly to the transmission output 8 Priority through the second switch 53 of block 19. In order for the device to work properly, the following condition must be met when powering the channels; if there is no power in all channels, it is necessary to supply power first only in one channel and then, after a time longer than the maximum delay time of the delay element 45 of the priority transmitting node 18, which one of the device’s channels, for example, the last one, feed power to all other channels in any order. It was pre-polo .xIM that there was no power supply in all channels of the device and is currently supplying it to any one channel. Since the two-stage trigger 43 of the priority transfer node 18 of this channel was set to zero, when the power was turned on, the control line would have a low level signal from the output of the two-stage trigger 43 of the priority transfer node 18 through the second matching element 23. At the same time, the output of the HE element 44 of the node 18, the priority will be transmitted a high level signal which, through the delay of the delay element 45 of the priority transmitting node 18, will set to 1 trigger 43 of node 18 via a single input. Thus, the highest priority will be captured by this channel in the device (the highest priority and its transmission from channel to channel will be discussed in detail later), a high level signal is generated on the control line, and the outputs of the HE element 44 and delay element 45 of the priority transmitting node 18 low level signal Thereafter, the power supply in any other channel of the system will not cause the installation of the two-stage trigger 43 of the priority transmission node 18 into one state, since a high level signal is present on the control line. This eliminates the possibility of setting the single state of the two-stage triggers 43 priority transmission nodes 18 for several

channels at the same time after turning on the power in the channels and, therefore, the possibility of capturing the highest priority in the device at once by several channels is excluded.

The matching elements 22 and 23 can be implemented on open-collector logic elements to connect the outputs 4 to the request line and the control outputs 9 to the control line according to the INSTALLING OR scheme.

The switches 52 and 53 of the block 19 can be made on gerkanovy or electromagnetic relays.

When a high level signal arrives at the input 10 of requesting a channel from the corresponding information source, the trigger 26 of the synchronization node 14 is set in a single state, fixing the request. After obtaining permission to access the data bus on output 12 of the exchange of information source 1, information is exchanged and then resets trigger 26 of synchronization node 14 to reset input 1 to the initial (zero) state. Thus, all the time while the trigger 26 of the synchronization node 14 is in a single state, this channel is indicated by an unserved request.

During operation, requests from information sources arrive at the channellt at random points in time, so at each current time point there may be several channels with unserved requests at the same time. After a data channel is released by any channel (when the signal goes from the low to high level), channels are arbitrated, during which only one channel with higher priority among the channels that currently have no access to the data line gets access to the data highway. requests.

Consider the arbitration of the system channels if there are several channels with unserved requests, and one of these channels has the highest priority.

In the channel with the highest priority, the two-stage trigger 43 of the priority transmitting node 18 is in a single state. When the data exchange path is released by any channel, the signal drop in the inhibit line from low to high through output 4 of prohibition, input 3 of node 14, element 25 of node 14 and output 32 of this node sets trigger 16 to unity state on the synchronization input. At the same time, through the OR element 21, as well as through input 59 and output 56 of block 19, at the exit 6 of the polling of this channel, a high level signal is blocked, blocking access to the trunk of sources with lower priority. Since the two-stage trigger 43 of node 18 of this channel is in a single state, the first input of the element 20 will have a low level signal from the zero output of the two-stage trigger 43 of node 18 and, therefore, the output of the element 20 will have a low level signal regardless Q no signal at input 5 of polling this channel, arriving at the second input of element I 20 through input 60 and output 53 of block 19. After the trigger 16 is set to one, a high level signal appears at the output of element 1 7 delay and through the input 40 of the node 15 and the element And 35 of this node it goes to the output 39 of the node 15, as well as to the output 2 permits; about; "en, permitting such about;:. ZOM access to the highway data exchange ..-; ь the source of information, under;

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this channel having the highest

current priority. In addition, a high level signal from output 39 of node 15 will cause the appearance of a kizko signal; -;); exactly in the line of prohibition through the element KE 24

5 and matching element 22. This situation in this case will indicate the seizure of access by the data exchange channel with the highest priority channel.

In each channel with a higher BF COKHM priority, having an unqualified request, after setting the trigger 16, ei is a fictitious state, the high level signal from the th output will propagate through the OR element 21, input 59 and output 56 of unit 19 to exit 6 poll.

5 High level signal from output 6 of polling channels with. the unserved request will be distributed along the polling line through polling input 5, input 60 and output 55 of block i9, element AND 20, element OR 21,

„IO: and. 59 and output 56 of block 19, output 6 p

polling in each channel, except the channel with

the highest priority (he has a low level signal at the first input of the AND 20 element), to all.

Thus, after a certain interval of 5 times, somewhat smaller than Ti (b1) cm. Delay of passing a high level signal through delay element 17, lag), K ;; n; i.ia) 3 any point of the polling line, 4 TO i; icTBa will be present sigmal

BMCCJAOro ypCBiifl, which in KaiiJi. KiA with

0 priority (the highest one will reset triggers 16 if they were set to the zero state through polling inputs 5, inputs 60 and outputs 55 of blocks 19, elements 20, inputs 42 nodes 5, e.pemey 34 nodes 15, Outputs 39 of these nodes.

5 inputs 30 nodes 14, elements 27 of fishing 14 and outputs 33 of these nodes.

From the moment of the release of the communication highway, i.e., from the moment of the signal transfer from low to high in the barring line, the triggers of 16 channels that currently have unserved requests from relevant information sources are set to one. Then, for a time interval slightly lower than T |, arbitration occurs, during which the triggers 16 of all channels are reset, except for the channel with the highest priority. Dissolution of the exchange can be issued to the source of information by any channel of linsh after the interval T | (when a high level signal appears at the output of the delay element 17), as well as at the input 41 of the high signal level node 15 from the output of the trigger 6 and at the n signal; - ;; Evil 15. Tzkoe vc. is performed only for kg. of the highest priority and only this q. l: l of all unmetered requests, gives permission to exchange the source of information.

Consider the arbitration of the channels of the device in the case of.tichs in the device of several channels with an unserved request, and one of these channels does not currently have the highest priority.

In any case, the system at each current time is, and,; there is a goal, which has the highest priority. Before the release of highway o6 ;. yes; -; - with any channel, the channel with the highest priority did not receive a request from the information source and the trigger 25 of node 14 of this channel is in the initial (zero) state, the output 6 of the poll of this channel will contain a low level signal , since the first input of the element OR 21 will contain a low level signal from the output of the element AND 20 (the first input of the element AND 20 contains a low level signal from the zero output of the two-stage trigger 43 of the priority transmitting node 18) and the second input of the element OR 21 will be assigned The trigger signal from the trigger output is 16.

Thus, at the output b of the polling of the channel with the highest priority during the release of the communication highway, there is a low-level signal that is fed to the input 5 of the next channel polling, allowing it to exchange. If a given channel has an unserved request, it will exit all other channels that have unserved requests through exit 6 of the poll, but the polling lines will drop all the triggers 16 in the same way as described by resetting the channels that have unserved requests to them. If this channel did not receive a request from the source of information, y; its like that of the channel with the highest output priority

b polling there will be a low level signal, ONLY) A common exchange of all other channels.

Takigu way, in our

Of all the channels with an unserved request, access to the data exchange highway will receive only one channel closer to the channel with the highest priority in the direction of signal propagation along the polling line.

When forming in the process of arbitration by any channel for exchanging the barring line through the NOT element 24, the matching element 22 and the output 4 of the ban for this channel receive a low signal

Level 5, indicating the seizure of access to, rHCTpa ;;;, the exchange of data G71I these, 5

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The source of information, having received permission- {exchange of information from the channel that captured the access, understands the exchange of data, after

which is fed to the input 11 of the reset of this channel by a high level signal, resetting the trigger 26 of node 14 to the initial (zero) state, as well as through trigger OR 27 of node 14 - the trigger 6. At the same time, the high signal at the output 12 of the exchange resolution and in the line of prohibition through the element NOT 24, the matching element 22 and the output 4 of the prohibition PS-YAEITSY signal high ypOBKFT, St.: hetelst: which is about the release and the trunk dunk: g Kaiia

0 psm After this, when CRYRTIINY in the system of sources, with unsuccessful sekkyl-: inquiry, the described process of arbitration begins. The priority of each channel is not firsirzanky and is shifted cyclically from the O.CENO channel to the other as a result of each current transmission. The cyclic shift of priority is made with the spacing of node 18. Suppose that for the current moment of time one of the channels is set. In a single state, a two-stage trigger 43 of the node 8. Then a high level signal will be present at the input 7 of the next channel. At that time, one of the system channels is transmitting data through the trunk, while a low signal is present on the bar

5 levels. At the time of the end of the transfer of signals, the signal drop from low to high in the inhibit line through the inhibit input 4 will result in the recording of a high signal from the output 7 of the channel priority transmission through input 6 and the first output

0 54 blocks 19 in the weft trigger (first of all) of the two-stage trigger 43 nodes 18.

After any of the channels starts transmitting, a signal drop from a high level to a low in the inhibit line will cause the signal from the first stage of the two-stage trigger 43 of the node 18 to be overwritten, and then from the single output of the two-stage trigger 43 of the node 18

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through the switch 53 of block 19, it will cause the appearance of a high level signal at output 8.

The signal from the output of channel 8 will be fed to the input 7 of the next channel. At the beginning of the next transmission, the two-stage trigger 43 of the priority-transmission node 18 of the first channel is set to the zero state, and the two-stage trigger 43 of the node 18 of the next channel is set to one, and so on.

The channel for which the two-stage trigger 43 of node 18 is set to one at the beginning of the current transmission becomes the highest priority, since the low level signal from the zero output of the two-stage trigger 43 of node 18 prohibits the high signal from the interrogation input 5 from passing And 20 and none of the other channels thus can prohibit the exchange of data to this channel on the input 5 of the survey. This channel, if necessary, data exchange will be able to prohibit the exchange of all other channels at the exit of the survey b.

As a result of switching on and off the individual devices of the system, such a situation may arise when all the channels of the two-stage triggers of the 43 nodes 18 turn out to be in the zero state.

In this case, when switching a two-stage trigger 43 knot. 18 of the channel transmission to the zero state, a low level signal appears on the control line, which allows the delay elements 45 to operate for the priority transmission nodes 18 of all channels.

The delay time of the delay element 45 of the priority transmitting node 18 is different for all channels and is proportional to the channel number.

Suppose that some channel has the smallest number and this channel is on, then the signal from the output of the delay element 45 of node 18 of this channel sets the two-stage trigger 43 of node 18 to one state. At the same time, in the control line, a high level signal is generated that will block the operation of the delay elements 45 of the nodes 18 of all channels, and the system will be automatically restored.

Claims (2)

1. A multichannel device for priority connection of information sources to a trunk containing channels whose inhibit outputs are connected to the device inhibitor bus, the polling output of each previous channel is connected to the polling input of the subsequent channel, except the last and first channels, output op-. the dew of the last channel is connected to the polling input of the first channel, the query input, the input iO the reset and exchange enable output of each channel are the corresponding request and reset inputs of the device and the output of the device’s system resolution, 5 each channel contains a priority analysis node, a trigger, a delay element, two matching elements and a synchronization node whose first input is connected to the input channel request, the second input of the synchronization node is connected to the reset input of its channel, the first output of the priority analysis node is connected to the third input of the synchronization node, the second output of the priority analysis node is connected to the output of exchange of own channel, 5 the trigger installation input is connected to the first output of the synchronization node, the reset input of the trigger is connected to the second output of the synchronization node, the trigger output is connected to the first input of the priority analysis node via the delay element, the trigger output is connected to the second input of the node priority analysis, characterized in that, in order to increase the reliability of the device, by providing guaranteed access to the exchange of data, each information source by cyclically shifting the priority of Between the channels, a priority transmission node, a switch unit, an AND element, an OR element and an NO element are entered into each channel, the first input of the priority transmission node is connected to the first 0 output of the switch block, the second input of the priority transmission node is connected to the channel inhibit output, to the fourth the input of the synchronization node and the output of the first matching element, the third input of the priority transmitting node is connected to input 5 of the initial installation of the channel, the fourth input of the node before, the priority priority is connected to the control output and to the output the second o matching element, the first output of the priority transmitting node is connected to the first Q input of the And element, the second output of the priority transmitting node is connected to the first input of the switch unit and to the input of the second matching element, the second output of the switch unit is connected to the second input of the And element whose output 5 is connected to the third input of the priority analysis node and to the first input of the OR element, the second input of which is connected to the trigger output, the output of the OR element is connected to the second input of the switch unit, the input of the first matching element men- 0 ta is connected to the output of the element NOT, whose input is connected to the channel exchange enable output, the third input and output of the switch unit are connected respectively to the input and output of the channel polling, the fourth input and output of the switch unit S are connected respectively to the input and output of the transmission channel priority, the initial setup input of each channel is the corresponding initial input eleven device settings, the priority transmission output of each previous channel is connected to the priority transmission input of the subsequent channel, the monitoring outputs of all channels are connected to the control panel of the device. 2. The device according to claim 1, characterized in that the priority transmitting node contains; there is an NOT element, a delay element and a two-stage trigger, the information I input of which is connected to the first input: a node, a two-stage synchronization input the source LfH0OpMG (4IJu2 Fy 35 FIG. 12 the trigger is connected to the second input of the node, the reset input of the two-stage trigger is connected to the third input of the node, the zero output of the two-stage trigger is connected to the first output of the node, the single output of the two-stage trigger is connected to the second output of the node, the input of the element is NOT connected to the fourth input of the node, the input of the delay element to the output element NOT, the output element delay connected to the installation input of a two-stage trigger. To i / cmof uHi / insrormation 39 Fi. FI.5