Browse Prior Art Database

Bypassing Disabled Terminal Nodes in Loop Communication Networks

IP.com Disclosure Number: IPCOM000076802D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Audretsch, LM: AUTHOR [+2]

Abstract

In loop communication networks, having active repeater terminals in series with the loop transmission medium, it is useful to be able to identify and bypass a faulty terminal with economical deployment and usage of hardware in the bypass function.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 65% of the total text.

Page 1 of 2

Bypassing Disabled Terminal Nodes in Loop Communication Networks

In loop communication networks, having active repeater terminals in series with the loop transmission medium, it is useful to be able to identify and bypass a faulty terminal with economical deployment and usage of hardware in the bypass function.

Fig. 1 shows a typical loop with one way (clockwise) signal traffic. In such systems, identification of a faulty terminal Ti can be effected by a time-out procedure initiated by the individual terminals. The terminal Ti+1 next beyond the faulty terminal Ti, in the direction of signal flow, being the only terminal failing to receive a basic time-out signal function from its immediate predecessor terminal, "knows" thereby that Ti is malfunctioning. Ti+1 can also initiate and control the bypassing of signals around the active circuits of Ti through additional hardware expedients described next.

Assuming for instance T1 is identified as defective at T2, bypass control source circuits BCS (Fig. 2) in T2 transfer bypass control signals, in the reverse direction over the loop transmission medium, to bypass control receptor circuits BCR in T1, which govern closure operation of normally open switch contacts on switching circuits SW in bypass transmission line segment BTL of T1. Segment BTL shunts the active repeater network formed by receiving circuits R and driving circuits D.

Details of one implementation of the T1 bypass with make-before-break reed- relay contac...