Fault detection process and system for a time-division switching network

A fault detection system for a time-division switching network comprising:

• first means for producing a partial origin coded data associated with each coded sample delivered by various input time-division channels of said switching network;
• second means coupled to said first means to insert into said switching network said partial origin coded data together with its associated one of said coded samples;
• a switching network output coupled to said second means, said network output having various output time-division channels;
• third means coupled to said network output for separating said partial origin coded data from its associated one of said coded samples;
• fourth means coupled to said third means to determine bit by bit the address of that one of said input time-division channels delivering said coded sample received in one of said output time-division channels from said partial origin coded data associated with said coded sample received in said one of said output time-division channels;
• a switching network control computer unit;
• memory means coupled to said computer unit to store the address of said one of said input time-division channels as supplied by said computer unit;
• fifth means coupled to said memory means and said fourth means to determine transmission delays in said switching network affecting said coded sample and its associated one of said partial origin coded data in said one of said output time-division channels;
• sixth means coupled to said fifth means and said memory means to select a stored address bit as a function of said delays;
• seventh means coupled to said memory means and said fourth means to compare a bit of said received partial origin coded data with said selected stored address bit;
• and
• fault signalling means coupled to said computer unit and said seventh means responsive to differences detected by said comparison so as to inform said computer unit accordingly.