Data transmission system utilizing loop transmission lines between terminal units

摘要

There is disclosed a data transmission system comprising a first and a second loop transmission line for transferring data in its clockwise and counterclockwise directions, respectively. In each loop transmission line a plurality of transmission control units are connected in series. Further, a plurality of terminal units each are interconnected with its associated first and second transmission control units correspondingly and respectively located in the first and second loop transmission lines. Each of the transmission control units in the first loop transmission line is interconnected to a corresponding one of the transmission control units in the second loop transmission line by a bypass line so as to make a pair, so that a fault in the loop transmission line may be detected and a loop transmission line bypassing the fault point may be established without using any master transmission control unit.