PSSu E F 4DO 0.5-R 315210 PSSu, electronic module, failsafe, digital inputs and outputs, 4outputs, 0.5 A, single-pole, positive-switching, short-circuit proof,overload-proof, free from feedback, for railway applications. The PSSuniversal Assistant is used for selection of the modules and for configuration of the decentralised I/O system PSSuniversal.