The Siemens 3RK2400-1BQ20-1AA3 is a K45 compact digital I/O module for AS-Interface field networks, rated IP67 for direct machine-mount deployment. It provides 2 PNP inputs and 2 PNP outputs, with a maximum output current of 3 A per module. The module requires an external auxiliary power supply of 20 to 30 V DC (PELV per VDE 0106, protection class III) to drive the output circuits — the AS-Interface bus cable alone cannot supply the output side.
Rated IP67, the module withstands washdown and dust ingress — suitable for food-and-bev lines, conveyor sections, or packaging machines where the I/O point lives on the machine frame, not in a cabinet. The 3 A max per module governs total output current; each of the two PNP outputs shares this budget. If you need to drive two 2 A solenoids simultaneously, this module is undersized — watch the per-channel allocation. Inputs are PNP (sourcing), minimum signal-1 current 6 mA, max signal-0 leakage 1.5 mA. That means a standard 3-wire PNP proximity sensor drives it cleanly; NPN sensors require an interface converter. Built-in short-circuit and induction protection on the outputs means you don't need external free-wheel diodes for small inductive loads — the module handles it.
Because it is an active, non-obsolete part, the sourcing path is straightforward: submit an RFQ with your quantity and target delivery window. No last-time-buy or surplus-channel scramble needed.
Four M12 sockets handle the I/O wiring. Pin 1 is sensor supply L+, pin 3 is sensor supply L-, pin 5 is ground terminal (outgoing via flat tab sleeve 2.8 x 0.8 mm form A). Data inputs on pins 2 and 4. Addressing is set via the front addressing socket; the module operates as an A/B slave. Yellow LEDs indicate I/O state, green LED shows auxiliary power present.