(under subclass 225) Subject matter wherein the multiplex system has a primary and a backup line, and the backup is activated to routed information data when the primary channel is malfunctioning.
SEE OR SEARCH CLASS
340, Communications: Electrical,
825.01, for selective communications with a spare channel.
714, Error Detection/Correction and Fault Detection/Recovery,
4, for replacement with spare transmission facility or channel which is not a multiplex communication system.
