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Bypass Function for Stations on a Closed Communication Loop

IP.com Disclosure Number: IPCOM000075009D
Original Publication Date: 1971-Jul-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Barnes, EN: AUTHOR [+4]

Abstract

This is a technique for operating a serial looped communications network, in which a faulty station on the loop may be bypassed so as not to adversely affect data transmission to other stations on the serial loop.

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Bypass Function for Stations on a Closed Communication Loop

This is a technique for operating a serial looped communications network, in which a faulty station on the loop may be bypassed so as not to adversely affect data transmission to other stations on the serial loop.

Fig. 1 shows an N-station loop in which the bypass function can only be provided by direct command from the central station. If a station is unable to respond to this command due to faulty equipment, communications to other nonfaulty stations will under some circumstances be terminated.

A single station, illustrated in Fig. 2 may be equipped with an additional shift register and a compare circuit, which continuously compares the contents of the serial shift register 1 with the contents of shift register 2. If all bits in the two registers do not compare, the bypass function is initiated to effectively remove the station from the loop. The bypass function is inhibited when the station is sending a distress signal, which may be sent under certain failure conditions, which will require a response from the central station.

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