The 6SL3210-1KE21-3UC0 is a SINAMICS G120C variable-frequency drive rated for 5.5 kW output with a 150% overload capability for 3 seconds — enough headroom to handle short-duration load spikes on a conveyor or pump without oversizing the drive. The I/O complement — 6 digital inputs, 2 digital outputs, 1 analog input, 1 analog output — is enough for basic speed control and feedback on a standalone machine; for more complex sequencing you'd add a PLC over the CANopen bus. Integrated Safe Torque-Off (STO) meets the safety-circuit requirement for unexpected-start prevention per EN 61800-5-2, so you can wire the safety relay directly to the drive without an external contactor for the power disconnect.
The FSB frame size measures 196 x 100 x 203 mm (H x W x D) with IP20 / UL Open Type protection — it mounts inside a clean, dry control cabinet, not on the machine frame. CANopen is the onboard fieldbus; no option card needed for that protocol. If the line speaks PROFIBUS or PROFINET, you'll need a separate communication module (the G120C family accepts them on the side slot).