What it is and what it does
The Siemens 3RK1402-3CE01-0AA2 is an AS-Interface standard slave module in the SlimLine S22.5 form factor — 45 mm wide, 106 mm tall, 86 mm deep — carrying four digital inputs and four solid-state switching outputs. It mounts on a 35 mm DIN rail or directly to a panel wall using the push-in lugs. The IP20 rating means it belongs inside a control cabinet, not on the machine frame in washdown zones. Each of the four channels — D0 (IN1/OUT1), D1 (IN2/OUT2), D2 (IN3/OUT3), D3 (IN4/OUT4) — is a floating pair: the input and output circuits are galvanically isolated from each other and from the AS-Interface bus. The inputs are PNP transistor type, 20–30 V DC. The outputs are solid-state, delivering 22–24 V DC at 24 V nominal.
Power and wiring constraints
This module requires an external auxiliary supply of 20 to 30 V DC, compliant with VDE 0106 (PELV), protection class III, to power both the input and output circuits. The AS-Interface bus cable alone does not carry enough current for the outputs — the AUX POWER pair is mandatory. The aggregate current across all outputs is capped at 200 mA at 40 °C ambient, with a total module limit of 4 A. Terminals accept 1 x (0.5–4) mm² or 2 x (0.5–2.5) mm² solid/stranded; with end sleeves, 1 x (0.5–2.5) mm² or 2 x (0.5–1.5) mm². AWG equivalents: 2 x (20–14). The built-in watchdog, short-circuit protection, and induction suppression mean the module handles fault isolation without external clamp diodes on the output side.
Configuration and diagnostics
Addressing is done via a front-facing socket. The I/O configuration code is 7, and the ID/ID2 code is 0/F. Status LEDs: green for AS-Interface communication, yellow per-channel for I/O state, red for fault. The module supports 2- and 3-wire sensor/actuator technology. Storage temperature range: –40 to +85 °C; operating: –25 to +70 °C.