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Marginal Communication Line Fault Detention

IP.com Disclosure Number: IPCOM000083251D
Original Publication Date: 1975-Apr-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Maholick, AW: AUTHOR

Abstract

In communication line circuits, it is often desirable to be able to determine if a line is operating out of adjustment or under marginal conditions when an excessive number of transmission errors occur, or if the errors occur in the terminal equipment. The system diagrammed will provide for a recognition of such deteriorated lines.

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Marginal Communication Line Fault Detention

In communication line circuits, it is often desirable to be able to determine if a line is operating out of adjustment or under marginal conditions when an excessive number of transmission errors occur, or if the errors occur in the terminal equipment. The system diagrammed will provide for a recognition of such deteriorated lines.

The procedure is to look for a string of erroneous messages in which there is no long string of good transmissions. For example, it may be assumed that as long as strings of at least 700 messages are received without an error, the communications are satisfactory but that if a string of 3000 messages are received without such a good string, the line is so subject to occasional noise and other error conditions as to be unsatisfactory for data purposes. The occurrence of such error conditions may be indicated or recorded for service information.

As indicated in the diagram, the detection of an erroneous character in a message will set an error trigger 1 to an "on" state which opens a gate 2 and deactivates a gate 3. When an end-of-message signal is received on line 4, it passes through gate 2 and over line 6 to set an error memory trigger 5 to indicate that an error burst has started or, if trigger 5 had been set earlier, has continued. The signal on line 6 is also passed to reset error trigger 1 in readiness for the next error detection, and will also be counted in a burst-length counter 7. The error signal on...