What 1FK2104-4AF11-1MB0 actually is
The 1FK2104-4AF11-1MB0 is a SIMOTICS S-1FK2 HD synchronous servo from the 1FK2 family built to drop onto a SINAMICS S120 drive line through the DRIVE-CLiQ feedback interface. It is a low-inertia, high-dynamic servo with an integrated holding brake, sized for the smaller end of the S-1FK2 HD range where positioning accuracy and short-cycle braking matter more than continuous torque. It carries a standstill torque M0 of 1.27 Nm and is rated PN = 0.4 kW at nN = 3000 rpm on a 380-480 V drive bus, with a second rating of PN = 0.2 kW at nN = 1500 rpm on a 200-240 V bus — the same stator on two different line rails, so the same order code covers machine builders shipping into both 230 V and 400 V geographies without a motor SKU change.
Feedback, brake, and the connectors on the back shell
Position feedback is the AM22DQC absolute encoder at 22-bit singleturn resolution plus 12-bit multiturn — that is roughly 4 million counts per revolution and 4096 turns of true multi-turn retention, so the axis does not need to home on every power-up after a controlled stop. The feedback runs over DRIVE-CLiQ on an M17 plug and the power comes out an M17 power connector — both M17, both specified by the same Siemens connector family, which keeps the cable set on the BOM to two M17 cordset part numbers instead of a mixed M17/M23 stack. The integrated holding brake is the standard 1FK2 fail-safe holding brake for this frame — sized to hold the rotor at zero speed with the rated M0 on the shaft, used as a holding brake only and not as a dynamic stopping brake.
Shaft, sealing, and panel-side mounting
Output shaft is D19 x 40 mm with a feather key — a short, keyed shaft for a coupling or pinion mount, not a keyed through-shaft; the 40 mm length gives enough engagement for a zero-backlash clamping coupling or a small pinion without overhanging the bearing. Degree of protection is IP65 on the motor body — dust-tight and resistant to low-pressure water jets, which covers the typical washdown profile of a food, beverage, or pharma machine where the servo sits behind the splash zone but not submerged.
Compliance, planner codes, and returnability
Export control classifies the motor AL:N / ECCN:N_CNDU — no special export licence gating in the usual jurisdictions. Siemens assigns Group Code R220, Product Group 9021, with product class C — built to order, not returnable for credit. That class C tag is the part of the ledger that drives the planner's MRP settings: minimum order quantity is one piece but the unit is produced against the order, not pulled from finished-goods stock. Lifecycle stage is current and the product status is active, so this is not a last-time-buy position — the BOM line stays on the standard Siemens build-to-order channel.