Topological conditions for fault diagnosability at subnetwork-level

In fault analysis of analog circuits at subnetwork level, there are two essential problems: to determine whether all the torn nodes are accessible, and whether there are some topological conditions of the subnetwork which guarantee the fault at subnetwork-level to be diagnosed correctly. These problems are solved by the authors. The result is necessary and almost sufficient. If all torn nodes are to be accessible, the required topological conditions would be almost satisfied automatically. It is a special case of the authors´ research in the distribution of the accessible nodes