AS-i I/O slice for the control cabinet
The Siemens 3RK2400-2CG00-2AA2 is a Slimline SC22.5 AS-Interface I/O module — 4 digital inputs (PNP Type 2) and 4 digital outputs (PNP transistor) in a 22.5 mm housing that snaps onto DIN rail. It's an A/B slave per AS-i Spec 3.0, profile S-7.A.7, with the ID1 code fixed at 7.
This module draws 200 mA when powered solely from the AS-Interface cable, or 500 mA when an auxiliary feed (AUX POWER) is connected — that's the difference between a bus-powered sensor cluster and one that also drives output loads. The auxiliary feed must be 20 to 30 V DC, PELV per IEC 60990, and it supplies the output circuits separately from the AS-i bus. The AS-i bus itself provides 8.5 V to the module's logic.
Output current and auxiliary supply limits
Each output is rated 270 mA at 30 V maximum (or at 24 V with AS-i Power24V), and the total current available from the auxiliary feed for all outputs is 4 A. The AS-Interface cable itself can deliver up to 2 A to the module. For a field-service swap, that means you can drive small solenoids or indicator lamps directly from the module's PNP outputs without an interposing relay — but watch the per-channel limit.
Mounting and environment — built for the cabinet
Screw and snap-on mounting on DIN rail, 22.5 mm wide, 100 mm high, 120 mm deep — standard Slimline footprint that fits alongside other SC22.5 modules. IP20 rated, so it's strictly for the control cabinet, not washdown zones. Shock resistance: 15g / 11 ms for the module alone, 10g / 11 ms with the device connector attached. Wiring accepts 0.5 to 1.5 mm² solid or stranded, or 0.25 to 1.0 mm² finely stranded with ferrule.