SU1495794A1 - Multichannel priority unit for servicing requests - Google Patents

Abstract

The invention relates to computing and can be used in an information exchange system, in particular, to provide access to a public device. The purpose of the invention is to increase the reliability of the device by eliminating the possibility of simultaneously issuing signals for servicing several sources of information. Achievement of the goal is achieved by introducing the element HE 3 and each channel 6 of the element OR 11 and the delay element 12 into the device. The device allows the processing of requests in the priority and sequential polling modes. The element NOT 3 provides switching modes, and the elements 1,9,10, and the delay element 12 block the passage of the polling signal to the next channel during the polling of this channel. 1 il.

Description

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The invention relates to computing and can be used in an information exchange system, in particular for accessing a public device.

The purpose of the invention is to increase the reliability of the device by eliminating the possibility of simultaneously issuing signals for servicing several sources of information.

The drawing shows a block diagram of the device.

The device contains an element AND 1, an element SH 2, an element NOT 3, an input 4 device modes, an input 5 polling a device, channels 6, each of which includes triggers 7 and 8, elements iH 9 and 10, element OR 11, delay element 12, device request inputs 13, device response inputs 14, device outputs 1 5.

The device can operate in one of two modes.

If there is a logical unit at input 4, the priority mode (in this mode, after the service of the spent information source is terminated, the survey starts from the channel that serves the information source with the highest priority);

in the presence of a logical zero at input 4, the sequential interrogation mode (in this mode, after servicing the spent information source, the next one by channel number is polled),

The device works as follows.

In the initial state, input 4 is set to a signal corresponding to the specified mode of operation of the device, and the triggers 7 and 8 of all channels 6 go to the zero state (the device installation circuit to the initial state and information sources are not shown in the drawing ). Input 5 receives a pulse of a millet that, through the element SHSh 11 of the last channel 6 (the priority of the channel decreases with increasing its number) goes to the first channel 6, and, if before that, through inputs 13, for example, the first and second channels 6 the signals of requests from the corresponding information sources were received and the triggers of these 7 channels were set to one state, then the polling pulse sets the first channel 6 to the trigger 8 to one state. The zero signal from the zero output of this trigger blocks the passage to the second channel 6 of the pulse, the interrogation pulse delayed by the element 12 for a time not less than the response time of the trigger 8, and a single signal from the single output of trigger 8 goes to the output 15 of the first channel 6, allowing service to start the first source of information. After termination of the service of this source, input 14 of the first channel 6 receives a pulse, which sets the triggers 7 and 8 of the first channel to the zero state and (if a logical zero signal is set at input 4) through the OR channel 11 of the first channel it arrives as a polling signal That works the same way as the first. After servicing the second channel in succession (rto ring), all channels of the device will be polled.

If a single signal is installed at input 4, then after servicing the first information source, the pulse arriving at input 14 of the first channel and setting the triggers 7 and 8 of this channel to the initial state again through the elements OR 2, AND 1 and OR 11 of the last channel in the first channel 6 as a polling pulse. Thus, for the service, more priority channels will be allocated, and the service of a less priority channel will come after more, priority channels will be free during the survey. If during the survey of channel 6 it turned out that it is free, i.e. the request signal on input 13 was not received, etc., the interrogation sipal through the delay element 12 is an AND 9 element, and OR 11 of this channel enters the next channel 6 to interrogate it.

Claims (1)

Invention Formula Multi-channel priority device for service requests, co-i; the AND holding element, the OR element and channels, each of which contains two triggers and two AND elements, the first input of the AND element connected to the output of the OR element, on each channel the input of the device request is connected to the installation input in the first I trigger, each response input of the device is connected to the reset inputs of the first and second triggers of the same channel, the single output of the first channel trigger is connected to the information input of the second trigger of its channel, the zero output of the second channel trigger is connected to the first input of the first channel element And, different to , 4TOj in order to increase reliability by eliminating the possibility of simultaneous signaling for servicing several sources of information, the element NOT is entered into it, the element OR is entered into each channel and a delay element, and the device mode input is NOT connected to the first inputs of the second elements AND of all channels in each channel; the output of the second element AND is connected to the first input of the OR element, the second input of which is connected to the output of the first element AND, the second input of which is connected to the output of the delay element, the output element OR of each channel, except the last, is connected to the input of the delay element and the synchronous input of the second 0 trigger the subsequent channel, the output of the element AND is connected to the third input of the element OR of the last channel, the fourth input of which is the input of the device survey, the output of the element OR 5 of the last channel is connected to the input of the delay element and the synchronous input of the second flip-flop of the first channel, the response of the device is connected to the input. OR element, direct outputs 0 second channel triggers are device outputs.