Single-channel safety output

摘要

The present invention relates to a safety switching device (102) for fail-safely switching on and off an electrical load, and to a system comprising at least two safety switching devices (102,104) which interact in a fail-safe manner via a single-channel (106). The safety switching device (102) comprises a fail-safe control unit, a first and a second electronic switching element connected with a first and a second output terminal (14,24); and at least one input terminal for receiving a first switching signal that causes a switching of said switching elements. Said first and second switching elements each comprise an output which provides depending on the first switching signal an output signal having a first or second potential. A third output terminal (L11) connects said safety switching device (102) to a second safety switching device (104), providing a clocked signal (108) depending on the first switching signal and being monitored by said control unit for performing a cross fault detection.