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Fault Location in Serial Loop Data Transmission Systems

IP.com Disclosure Number: IPCOM000077309D
Original Publication Date: 1972-Jul-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Owen, CE: AUTHOR

Abstract

In a serial loop data-transmission system a number of stations distributed around the loop communicate with a common controller by entering data into a frame transmitted on the loop by the controller, the frame containing address data identifying a station currently using the loop together with other data performing signalling functions. A synchronizing signal is normally transmitted continuously and in order that a fault in the loop may be indicated to the controller and located thereby, each station is arranged to recognize the absence of a synchronizing signal on the loop, and in such event to generate a synchronizing signal together with a special instruction and a data byte of 1. Subsequent stations recognize the instruction and add one to the data byte.

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Fault Location in Serial Loop Data Transmission Systems

In a serial loop data-transmission system a number of stations distributed around the loop communicate with a common controller by entering data into a frame transmitted on the loop by the controller, the frame containing address data identifying a station currently using the loop together with other data performing signalling functions. A synchronizing signal is normally transmitted continuously and in order that a fault in the loop may be indicated to the controller and located thereby, each station is arranged to recognize the absence of a synchronizing signal on the loop, and in such event to generate a synchronizing signal together with a special instruction and a data byte of 1. Subsequent stations recognize the instruction and add one to the data byte. Thus on arrival back at the controller, the special instruction indicates that a fault has occurred and the number in the data byte indicates the location of the fault.

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