Definition — what the 1FK2104-5AF11-0SA0 is on the line
The Siemens 1FK2104-5AF11-0SA0 is a SIMOTICS S-1FK2 HD servomotor with an integrated holding brake, designed as the rotating load on a SINAMICS S210 axis module. It pairs a 2.4 Nm stall torque (M0=2.4 Nm) with two stack-rated power points — 0.75 kW at 3000 rpm on a 380-480 V link, and 0.375 kW at 1500 rpm on a 200-240 V link — so the same frame covers both 230 V-class and 400 V-class drive cabinets.
Sizing the motor — what the torque and power windows actually buy you
Holding M0=2.4 Nm with peak power scaling at 0.75 kW sets the practical axis envelope: continuous duty up to 3000 rpm from the S210 on a 400 V bus, or a halving to 0.375 kW if the drive line is held to 200-240 V — oversizing the upstream transformer is not required to reach the rated point. The holding brake is integral, so vertical or back-driving axes can fail-safe without adding a separate brake-and-clutch stack in the gearbox — cabling stays at a single M17 connector.
Feedback and wiring — encoder, connector, and shaft geometry
Position feedback is an absolute single-turn AS22DQC, 22-bit resolution — enough that an electronic gear on a flying-saw or a cyclic synchronous position move can hold nanosecond-class distributed-clock alignment across the rest of the 1FK2 string without re-homing on power-up. The shaft is a plain cylindrical D19x40 mm stub, the body seals to IP65, and the connector is an M17 rotatable plug — so cable routing can be rotated to the cabinet entry after the motor is bolted down, and the wet-side seal is at the plug face, not the thread.