PSSu H FS SN SD-R 315085 Communication modules PSSuniversal I/O, for implementation of safety-related and standard applications in the automation system PSS 4000. PSSu, head module, decentralised system PSSuniversal I/O, failsafe and standard, PL e, SIL CL 3, 2 RJ45 Ports, SafetyNET p RTFN, SD card, for railway applications.