PSSu A CE “Q” grey (10 pcs.) 312939 PSSu, coding elements for ST I/O and basic module, grey, coding Q, PU 10 pieces, packed in resealable polybag with marking sticker. PAS4000, the software for the automation system PSS 4000: Intuitive operation ✓ Hardware-independent ✓ Simple programming and configuration ✓ – Pilz – INT.