The Siemens 3RK2400-1BQ20-0AA3 is a K45 compact digital I/O module rated for field deployment at IP67, carrying 2 PNP inputs and 2 PNP outputs with a maximum output current of 3 A per channel.
The 3 A per-output rating is the continuous load limit for the PNP transistor outputs. The IP67 rating means the module body and all four M12 sockets are sealed against dust ingress and temporary immersion — suitable for washdown zones, outdoor conveyor sections, or food-and-beverage lines where hose-down cleaning is routine. Inputs are PNP (sourcing) type, so the module expects a positive signal from 3-wire sensors. The input circuit draws a minimum of 6 mA for a logic 1 and a maximum of 1.5 mA for a logic 0 — standard for most industrial 24 VDC PNP proximity switches and photoelectric sensors.
Power and wiring constraints
An external auxiliary supply of 20 to 30 VDC is required for the output circuits, and it must comply with VDE 0106 (PELV), protection class III. Dimensions are 45 mm wide × 80 mm high × 30 mm deep — roughly the footprint of a slim terminal block, so it fits in tight junction boxes or along DIN rails in small enclosures.