SIMATIC S7/PCS7, SM 321 DIGITAL INPUT MODULE, 16 DI, 24V DC, CAPABLE OF DIAGNOSTICS, FOR CONTACTS (CONNECED/UNCONNECTED), NAMUR SENSOR, 3/4-WIRE-BERO, WITH FLUTTER MONITORING, PULSE LENGTHENING, WIRE BREAK DETECTION, IM 153-2 INTERFACE MODULE REQUIRED
