PNOZsigma safety module (standalone), inputs: mono/bi-channel wiring with/without short-circuit detection, manual/automatic start, outputs: 3 NA, 1 NC, 1 SC, UB = 24 V DC, width: 22.5 mm, "plug-in" screw terminals, emergency stop control, removable, light curtains, combustion plants according to EN 50156-1.