The Siemens 3RK1903-3EA10 is a 15 mm terminal module designed specifically for the ET 200S inverter control module ICU. It provides the wiring interface between the ET 200S backplane bus and the inverter power stage, handling the control and feedback connections for the drive slice in a distributed I/O rack.
Integration note
The 15 mm width matches the standard ET 200S terminal module footprint, so it occupies one slot in the I/O station. Wiring is via the module's screw-type terminals; the backplane connector mates automatically when the module is snapped onto the rail.