Self-repairing ring communications network

A ring communications network comprising

• a pair of oppositely directed, unidirectional, substantially parallel signal paths having a plurality of interface units (IU's) coupled in series along said pair of signal paths, whereby each IU is coupled to one inbound signal path and one outbound signal path from each of said parallel signal paths, wherein each of said IU's includes:
• A. first detecting means for detecting when the two inbound signal paths coupled to that IU are operative and means responsive to said detection for coupling each of said inbound signal paths to the respective outbound signal path coupled to that IU which is parallel to the other inbound signal path,
• B. second detecting means for detecting when one inbound signal path coupled to that IU is inoperative and means responsive to said detection for interrupting signal flow on the outbound signal path parallel to said one inbound signal path, and means for coupling the other inbound signal path to the outbound signal path parallel to said other inbound signal path,
• C. reconnect network responsive to said second detecting means and operative when one of said inbound signal paths is inoperative, said reconnect network including means for periodically monitoring said inoperative inbound signal path, and including means for determining when said inoperative inbound signal path is again operative and, in response thereto for coupling said again operative inbound signal path to the outbound signal path at said IU which is parallel to the other inbound signal path at said IU and for coupling said other inbound signal path at said IU to the outbound signal path which is parallel to said again operative inbound signal path.