The Siemens SIMATIC 3RK1304-5KS40-5AA0 is a reversing motor starter — a compact, IP65-rated unit that handles forward/reverse control of a three-phase motor up to 2 A at 400 V AC, with a CLASS 10 trip curve for overload protection. It's built for distributed installation right at the motor, not back in a central panel, which cuts wiring runs and simplifies zone-based machine layouts. Supply is 24 V DC nominal (20.4 to 28.8 V range), so it plays nicely with standard control voltages. PROFINET and PROFIBUS DP are both onboard — no separate gateway module needed for the fieldbus connection. The 2-byte input and 2-byte I/O mapping keeps the data exchange lean for basic start/stop and status feedback.
Mounts via screw fixing in either vertical or horizontal orientation, which gives flexibility in tight enclosures or on machine frames. Dimensions are 150 mm deep, 110 mm wide, 230 mm tall — a compact footprint for a reversing starter with integrated bypass. The main energy infeed uses a socket per ISO 23570, so the power connection is standardized and keyed. Digital I/O connections are via M12 sockets — common for distributed I/O in food-and-bev or packaging lines where IP65 is needed. Environmental range covers -25 to +55 °C operating, -40 to +70 °C storage/transport. Shock rated at 15g / 11 ms, vibration at 2g — solid for machine-mounted duty on conveyors, pumps, or fans.