The Siemens 6SL3520-1XA61-1AF0 is the AS-Interface variant at 1.1 kW in the SINAMICS G115D distributed drive series, carrying the 1XA61 catalog designation. This product extends the 1XA61 range downward — previously confirmed only at 1.5 kW (batch 17), 1XA61 now covers 1.1–1.5 kW FSA as the upper-power half of the 1XA6x sub-series, paired with 1XA60 (0.37–0.75 kW FSA). Together they span the complete 0.37–1.5 kW FSA range.

Why three parallel sub-series at 1.1 kW FSA?

Siemens offers three parallel catalog codes for the same 1.1 kW FSA hardware: 1XA01-1 (1XA0x sub-series), 1XA21-1 (1XA2x sub-series), and 1XA61-1 (1XA6x sub-series). All three identify mechanically and electrically identical drives — same 380×216×129 mm FSA enclosure, same 3.1 A rated / 6.2 A overload output, same natural convection cooling. The sub-series distinction is commercial catalog organization. An engineer selects the part number their Siemens distributor stocks — not based on any engineering difference between the drives. This is comparable to how XE4x and XE0x coexist as parallel XE catalog sub-series.

When does AS-Interface make sense at 1.1 kW?

The AF0 variant communicates over the AS-Interface yellow flat cable — the same two-wire physical layer that carries 30 V auxiliary power. At 1.1 kW, the G115D typically drives accumulation conveyors and transfer units — the most numerous drive types on a conveyor line, where the per-node wiring simplicity of AS-Interface delivers the largest total system benefit. Every drive taps into the same flat cable with insulation-displacement connectors: no T-junctions, no switch ports, no RJ45 terminators. The 1XA61-1AF0 integrates into this architecture without adding Ethernet infrastructure to the lowest-power drive nodes.