There are times when the Analyst would like to quickly examine the diagnostic capability of a design without defining tests (such as when trying to determine the best locations to place sensors in a design). To facilitate this type of study, eXpress allows the Analyst to generate diagnostics using output I/O flags as if they were tests. When selected, the diagnostics will assume that each output flag can test every upstreamoutput function and failure mode (as would an Operational Test defined at that flag). Object States are ignored when determining the coverage at each flag (as if all states were enabled). In addition to test point placement studies, diagnostics that use only output flags for both fault detection and isolation can give the Analyst an idea of the degree to which ambiguity results from the design topology itself (as opposed to an inability to test individual elements within a design).
Tests and output flags can also be utilized together in diagnostics. Because the Test Candidate Groupings in the predefined Diagnostic Algorithms always use test set tests before they will use output flags as tests, diagnostics generated using both tests and output flags may indicate ways in which the existing set of tests can be improved by the defininition of additional tests.
