PITmode fusion is the modular version of the operating mode selection system and is the solution when a third-party safety controller is used. The system comprises the reader unit PITreader and the separate evaluation unit (Safe Evaluation Unit – SEU), which evaluates the selected operating mode and switches between up to five operating modes in a functionally safe manner. The operating mode can be selected using existing buttons or via the operation element PIT oe 4s. Of course, the full scope of the PITreader's access permission functions can also be used.