Abstract: The invention relates to a modular safety switching device system for switching actuators fail-safely off. The system comprises at least one input module for fail-safely evaluating a safety transmitter and for generating an output signal. It further comprises at least one output module for fail-safely actuating the actuator in response to the output signal from the input module. At least the input module can be operated in different selectable operating modes. A control module is provided for individually setting the operating mode of the input module and, if applicable, of the output module. A display is provided for fail-safely displaying the operating modes set.

Abstract: The present invention relates to a device and a method for safely monitoring the rotary motion of a shaft. The device comprises measuring means for recording a first and a second signal, wherein the first signal represents the motion characteristic of an angular position of a first reference point of the shaft and the second signal represents the motion characteristic of an angular position of a second reference point of the shaft. The first and the second reference points are displaced one relative to the other by a rotary angle of the shaft. Further, the device comprises evaluator having a comparator by means of which instantaneous values of the first and the second signals can be compared one with the other using a predefined geometric relation.