Operating method for a machine, for example a production machine, in particular a machine tool, - wherein the machine has a first actuator , - wherein the first actuator is embodied as a position-controlled or speed-controlled axis, - wherein the first actuator is controlled by a control device for the machine, - wherein the control device implements a controller structure for controlling the first actuator , - wherein, in both normal operating mode and a special operating mode of the machine, the control device in each case cyclically specifies to the controller structure a setpoint value (x*) for an action to be executed by the first actuator from a corresponding sequence of setpoint values (x*) and the controller structure in each case accepts said setpoint value (x*) and an actual value (x) for an action executed by the first actuator , determines a control signal (S) for the first actuator as a function of the setpoint value (x*) and the actual value (x) and controls the first actuator according to the control signal (S) determined, - wherein, in the normal operating mode, the setpoint values (x*) are determined by the control device using a utility program and, in the special operating mode, they are determined using a system program different from the utility program , - wherein, in the special operating mode, the control device captures the actual values (x) resulting from the setpoint values (x*), uses the sequence of setpoint values (x*) specified in the special operating mode and the associated captured actual values (x) to determine a frequency characteristic (FKL) for the first actuator , uses the frequency characteristic (FKL) and parameters (P1a, P1b, P2a, P2b) from the controller structure to determine an evaluation (B) for the first actuator and/or the controller structure and decides in dependence on the evaluation (B) whether to transmit a message (M, M'), and, if applicable, which message, to an operator of the machine or to a computing device over a computer network . - wherein the machine has a first actuator , - wherein the first actuator is embodied as a position-controlled or speed-controlled axis, - wherein the first actuator is controlled by a control device for the machine, - wherein the control device implements a controller structure for controlling the first actuator , - wherein, in both normal operating mode and a special operating mode of the machine, the control device in each case cyclically specifies to the controller structure a setpoint value (x*) for an action to be executed by the first actuator from a corresponding sequence of setpoint values (x*) and the controller structure in each case accepts said setpoint value (x*) and an actual value (x) for an action executed by the first actuator , determines a control signal (S) for the first actuator as a function of the setpoint value (x*) and the actual value (x) and controls the first actuator according to the control signal (S) determined, - wherein, in the normal operating mode, the setpoint values (x*) are determined by the control device using a utility program and, in the special operating mode, they are determined using a system program different from the utility program , - wherein, in the special operating mode, the control device captures the actual values (x) resulting from the setpoint values (x*), uses the sequence of setpoint values (x*) specified in the special operating mode and the associated captured actual values (x) to determine a frequency characteristic (FKL) for the first actuator , uses the frequency characteristic (FKL) and parameters (P1a, P1b, P2a, P2b) from the controller structure to determine an evaluation (B) for the first actuator and/or the controller structure and decides in dependence on the evaluation (B) whether to transmit a message (M, M'), and, if applicable, which message, to an operator of the machine or to a computing device over a computer network . <EOS>