Fault diagnosis of digital switching networks

Methods of fault detection and location for separate digital switching matrices as well as a wide class of switching networks are proposed. First, it is assumed that stuck-type faults can affect only a single component of a network. A model of a switching matrix is presented and fault equivalences are shown. After the discussion of single-switch diagnosis, test vectors and connection settings for identification of a single faulty switch in multistage networks are proposed. To avoid the masking effects, the notions of an H-test vector and an H-assignment are introduced. In the proposed approach, tests for space and time switching are performed separately. The problem of multiple fault detection is also considered