SWITCHING DEVICE FOR FAIL SAFE SWITCHING ON AND OFF A DANGEROUS MACHINE SYSTEM

A switching device shuts down a machine installation in failsafe fashion. The switching device includes an input for a defined input signal, a first output providing a first current path to the machine installation, a display element capable of assuming first and second states, and a processor having first and second modes of operation. The first current path includes a switching element capable of assuming closed and open operating states. In the first mode, the processor controls the switching element in response to the defined input signal in order to selectively close or interrupt the first current path. In the second mode, the processor controls the switching element into the open operating state regardless of the defined input signal. In the first mode, the display element assumes the first and second display states in response to the switching element being in the closed and open operating states, respectively.