What is RTCP for 5 Axis CNC Router? RTCP represents a tool compensation in the space.In five-axis machining, when the trajectory focuses on the tool nose point and the workpiece, the additional movement of the tool nose point occurs due to the rotary motion. The control points of the CNC system often do not coincide with the tool nose points, so the CNC system should automatically correct the control points to ensure that the tool nose points move according to the commanded trajectory.