Phoenix Contact 2900323 A PLC interface for railway applications features a basic terminal block with push-in connections and a plug-in miniature relay with multi-layer gold contacts in sizes from 0.7 x UN to 1.25 x UN. It operates within the temperature class TX at temperatures ranging from -40°C to +70°C, and comes equipped with one changeover contact. The interface accepts an input voltage of 110 V DC.