DATATRANSMISSIONSANORDNING FOR ATT FRAN EN CENTRAL PLATS ATERUPPRETTA EN SERIETRANSMISSIONSVEG SOM BRUTITS

摘要

A loop data transmission arrangement is disclosed in which a plurality of transmission terminals are serially connected to a base terminal by a primary transmission line and a secondary transmission line over which time-divided data signals are transmitted in opposite directions by the base terminal. Each transmission terminal and the base terminal are equipped with individual fault detectors to monitor signal reception on both the primary and secondary lines. The transmission terminals contain storage devices for storing signals from the fault detectors. In addition, the transmission terminals contain circuitry responsive to the signal outputs of the fault detectors and the signals stored in the storage devices for controlling transmission of signals on the primary and secondary lines. The base terminal contains circuitry for responding to the detection of a fault on one of the lines by terminating data signal transmission on the other line. The base terminal is also capable of stopping data transmission on both lines. The cooperative operation of the transmission terminals and the base terminal when a transmission fault occurs results in the isolation of the fault and the restoration of communication by selectively effecting connections between the primary and secondary lines.