Abstract: A safety circuit arrangement for the failsafe monitoring of a movement variable of a moving machine part has a signal input for supplying an encoder signal, with the encoder signal being representative of the movement variable to be monitored. The arrangement also has a reference signal path for supplying a reference signal, a tap connected to the signal input and to the reference signal path in order to provide a superposition signal by superposing the reference signal on the encoder signal, and a measuring unit which is connected to the tap and is designed to detect whether the superposition signal reaches at least one predefined signal level or is within a predefined signal level range.

Abstract: A safety circuit arrangement for the failsafe monitoring of a movement variable of a moving machine part has a signal input for supplying an encoder signal, with the encoder signal being representative of the movement variable to be monitored. The arrangement also has a reference signal path for supplying a reference signal, a tap connected to the signal input and to the reference signal path in order to provide a superposition signal by superposing the reference signal on the encoder signal, and a measuring unit which is connected to the tap and is designed to detect whether the superposition signal reaches at least one predefined signal level or is within a predefined signal level range.