Fault isolation in communications circuits

摘要

In a multipoint data communications system in which a central processing unit communicates with a plurality of remote terminals over a shared two-way communications facility, an automatic fault isolation circuit is provided to monitor energy levels originating at the several remote terminals. One or more energy level thresholds are incorporated into bridging locations through which incoming and outgoing address and message signals are distributed to, and collected from, remote terminals by way of the shared facility for the purposes of detecting noise buildups and isolating trouble conditions automatically without human intervention.