Abstract: A numerical control contouring system in which successive path segments are executed according to successive blocks of command signals making up a path program, the system being interruptable at any time by a feedhold signal to stop the controlled movable member at a random point on the path. The system is characterized by the improvement of preventing the system from resuming normal operation unless and until the member is returned to the path stopping point after it has been, for any reason, displaced therefrom under manual control or the like. In one embodiment, the axis component displacements of the member from the stopping point are represented by signals created and displayed, and the operator's restart pushbutton switch is rendered ineffective until the displayed displacement signals are reduced to zero.