Numerous applications of cyber-physical systems in safety-critical spheres of human activity are the main reason for the fact that the development of methods intended for on-line faults diagnoses in these systems is one of the actual problems. One of the essential sub-problems for this problem is the elaboration of models and methods intended for on-line checking of faults in cyber-physical systems. In the given paper this sub-problem is investigated under the supposition that these systems can be modeled by the 1-dimensional hybrid automata dened in the given paper. On the base of this model-based approach, some completely distributed system intended for on-line monitoring and fault components isolation in cyber-physical systems is proposed. This system consists of controllers of two types. Controllers of the first type are intended for checking the dynamics of physical processes, and controllers of the second type are intended for checking switching between dynamics. The structure of both types of proposed controllers is defined in detail. Necessary and sufficient conditions that guarantee for both types of proposed controllers that they carry out correct on-line checking are established and proved.