Fault recovery apparatus for a PCM switching network

摘要

This fault recovery system determines the integrity of a duplex digital PCM switching network. The two copies of the switching network operate in synchronization and comparison of the outputs of each copy of the switching network takes place in order to detect network faults. The fault recovery mechanism is chiefly provided by inserting PCM samples from maintenance registers into the PCM data stream, through the digital switching network and trapping said PCM sample for analysis by the program. Subsequently, the logical unit corresponding to each fault is determined and a count is recorded corresponding to each unit.