AS-Interface field module, 4 PNP inputs
The Siemens 3RK1200-0CU20-0AA3 is a K45 compact digital input module for AS-Interface networks. It provides 4 PNP inputs (3-wire sensor compatible) and draws its supply directly from the AS-Interface bus cable — no separate 24 VDC power feed needed. The module is rated IP65, so it mounts directly on machine frames or conveyor sections in washdown zones without an enclosure.
Each input switches at ≥10 V (High level) and sinks ≥6 mA at signal 1, with off-state leakage below 1.5 mA. That's standard for 3-wire PNP proximity sensors and photoelectric eyes. The module's total AS-Interface current draw is 270 mA max, and the sensor supply (pins 1/3) is short-circuit and overload protected — so a failed sensor won't take down the bus segment.
Mounting and addressing
The 45×80×30 mm housing clips onto standard DIN rail or mounts to a wall using the K45 mounting plate (ordered separately — the module ships without one). Addressing is set via the front socket; the factory ID/ID2 code is 0/F. Each of the four sockets maps one input: socket 1 PIN 4 = IN1 (D0), up to socket 4 PIN 4 = IN4 (D3). Yellow LEDs show input state; a green/red dual LED reports AS-Interface communication and diagnostics.