Diagnosability of linear active networks

The problem of diagnosis studied here is to determine the currents and/or voltages of desired elements from the measured currents and/or voltages of certain other elements. A necessary and sufficient condition for diagnosablity is given in connection with the structure of 2-graphs. The relationship between the structure and the electrical connectivity is presented to show the diagnosability depends on the connectivity of the network. In diagnosis of a large network it may often happen that only a part of the currents and voltages in the whole network need be solved. Some condition for this partial solvability is given.