The SINAMICS G115D 6SL3520-0XE47-5AF0 is the 7.5 kW wall-mounted distributed drive in FSC frame with AS-Interface (AS-i) communication — the alternative fieldbus variant to the PROFINET AB0 model at the same power rating. Designed for brownfield conveyor installations where an AS-i two-wire bus infrastructure already exists, the AF0 variant connects directly to the standardized yellow AS-i cable, carrying both power (24 V DC auxiliary) and cyclic process data to the AS-i master. At 7.5 kW in the FSC frame with integrated fan cooling, it delivers 17.1 A rated output current with 200% overload for 3 seconds — the highest-power AS-Interface drive in the SINAMICS G115D series.

How does AS-Interface differ from PROFINET on the G115D?

The AF0 (AS-Interface) and AB0 (PROFINET) variants share identical power stage hardware — the 7.5 kW FSC frame, motor interface, and cooling are the same. The difference is in the communication and safety architecture. AS-Interface uses a two-wire unshielded yellow cable that carries both 24 V DC auxiliary power and cyclic data to the AS-i master gateway — typically a simpler installation with less cabling than PROFINET but lower data bandwidth (typically 4 bits of cyclic I/O per node for a standard AS-i slave). For safety, the AF0 variant relies on the fail-safe digital input (F-DI) for STO rather than PROFIsafe — an external safety relay or emergency stop circuit provides the 24 V DC safety signal. This suits existing AS-i conveyor lines where the safety architecture is already built around hardwired emergency stop zones rather than networked safety protocols.

When to choose AS-Interface over PROFINET

AS-Interface on the G115D makes sense in three scenarios. First: the conveyor line already runs on an AS-i master with spare node capacity — adding AS-i drives means no new network infrastructure. Second: the application does not require high-bandwidth cyclic data — AS-i delivers setpoint and feedback at the master's scan rate, sufficient for basic speed control and status monitoring on conveyor sections. Third: safety is handled by existing hardwired emergency stop circuits rather than networked safety — the F-DI input accepts a standard 24 V DC safety signal without PROFIsafe configuration. If the conveyor is a new build, uses PROFINET for other drives, or requires networked safety with TIA Portal integration, the AB0 PROFINET variant is the better fit.

Motor compatibility and installation

Direct mounting to SIMOGEAR 2KJ8 geared motors in IE3 or IE4 efficiency classes with integrated 400 V AC brake control. Encoderless vector control in V/f and sensorless modes. The FSC frame at 425 × 240 × 169 mm with integrated fan cooling sustains continuous 7.5 kW operation at up to 40 °C ambient. The built-in EMC filter meets Category C2 (EN 61800-3).

Frequently Asked Questions

Can an AS-Interface G115D be upgraded to PROFINET later?

No — the communication interface is determined at the hardware level by the AF0 suffix. Converting an AS-Interface drive to PROFINET would require replacing the entire unit. For new installations where future PROFINET migration is possible, specifying the AB0 variant upfront avoids a later hardware swap. The AB0 variant also supports EtherNet/IP alongside PROFINET, providing additional protocol flexibility that AS-Interface cannot offer.

What AS-i profile does the G115D use?

The SINAMICS G115D AF0 variant operates as a standard AS-i slave with 4-bit cyclic I/O for basic speed control and status feedback. For full parameter access, diagnostics, and commissioning, the mini-USB port provides a direct connection to a PC running Startdrive or TIA Portal — the AS-i bus is used for runtime control only, not for engineering access.