Fault diagnosis of a distributed knockout switch

The distributed knockout switch has multiple paths between any input and output pair and thus is inherently robust to faults without the need of adding any additional switch elements. However, to achieve fault tolerance, one has to first detect and locate the faults. The authors present an efficient fault diagnosis procedure to detect, locate, and identify the fault type of single switch element faults for the switch element array of the distributed knockout switch. To facilitate fault diagnosis, the operation of switch elements is slightly modified. The diagnosis procedure can locate most single switch element faults in two phases. Faults which cannot be located in two phases can always be located in a third phase. Binary search algorithms are developed to locate some kinds of single switch element faults in the third phase