Abstract: A rotary machine element has at least one functional part performing movements into stop positions, which stop positions are nominal stop positions or mechanical terminal stop positions and are functionally correlated. At least one position sensor is provided for detecting individual actual position values of the stop positions independently from one another. At least one position sensor is located in a control path between the at least one functional part and an NC control. The control path is active in positions between the nominal stop positions; the mechanical terminal stop positions; or the nominal stop positions and the mechanical terminal stop positions. Based on acquired actual position values of the at least one functional part, the speed and acceleration of the at least one functional part are determined by NC-control.