The SINAMICS G115D 6SL3520-1XA21-1AA0 is the 1.1 kW wall-mounted distributed frequency converter in FSA frame with I/O Control — a compact, fanless drive in the SINAMICS G115D series 1XA21 catalog designation, configured for hardwired terminal-block control. At 1.1 kW FSA (380 × 216 × 129 mm), natural convection cooling eliminates fan maintenance — ideal for dusty or fiber-laden conveyor environments. It delivers 3.1 A rated output with 200% overload, driving IE3/IE4 motors via SIMOGEAR 2KJ8 direct mounting. I/O Control provides discrete digital inputs (run/stop, direction, fixed speeds), analog input (0–10 V / 4–20 mA) for speed reference, and F-DI for STO — the most direct control interface in the G115D lineup.

When to choose I/O Control over AS-Interface at 1.1 kW?

Choose AA0 when: (1) the PLC cabinet is adjacent — running a few discrete wires is simpler than configuring an AS-i node; (2) the machine builder standardizes on hardwired I/O for all drive sizes; (3) no AS-i infrastructure exists and there is no plan to deploy one. If the plant already has an AS-i backbone serving sensors and actuators, the AF0 variant integrates more naturally — two wires versus a multi-conductor terminal block.

Frequently Asked Questions

Can I add a fieldbus later?

No — the AA0 variant has no fieldbus interface hardware. Replace with AF0 (AS-Interface) or AB0 (PROFINET) for fieldbus connectivity.

What is the difference between 1XA21 and 1XA01 for 1.1 kW?

Catalog designation only. Both identify the same 1.1 kW FSA hardware — mechanically and electrically identical. Drives are functionally interchangeable.