PSSu BP-C 1/8 C-TJ 314613 Carrier units for the I/O modules and supply voltage modules. These modules are simply inserted on to the base modules and are easy to change when making system adjustments. PSSu, base module for electronic modules, periphery, C-rail, 1-row, 4 connection levels, 8 terminals, spring-loaded connection, cold junction compensation with integral Pt1000,for increased environmental requirements.