Characterization of (t1/t1/2)/s diagnosability

The authors have previously proposed a three-valued model, which admits the transmission of diagnostic data via a fault-free communication unit in a faulty subsystem, making available more test links than the original. Based on this model, a new diagnosability measure, (t¹/t^1/2)/s diagnosability, is introduced. A t¹/t^1/2/s -diagnosable system ensures the location of any fault set to within a set of no more than s subsystems provided it contains at most t¹ faulty subsystems with faulty communication units and at most t^1/2 faulty ones with fault-free communication units. Symmetric and asymmetric test invalidation are considered. In the light of multiple-fault-set consistency, (t¹/t ^1/2)/s diagnosability, either with symmetric invalidation or with asymmetric invalidation, is fully characterized