  In this paper, the possibility of detecting topological variations by
observing output trajectories from networked linear time-invariant systems is
investigated, where the network topology can be general, but the nodes have
identical higher-dimensional dynamics. A necessary and sufficient condition on
the discernibility of topological variations is derived, in terms of the
eigenspaces of the original and the modified network configuarations. By taking
the specific network structures into consideration, some lower-dimensional
conditions are derived, which reveal how the network topologies, sensor
locations, node-system dynamics and output, as well as inner interactions
altogether affect the discernibility. Furthermore, the output discernibility of
topological changes for networked multi-agent systems is revisited, showing
that some criterion reported in the literature does not hold. Consequently, a
modified necessary and sufficient condition is established. The effectiveness
of the results is demonstrated through several examples.

Optimization and Control