The Siemens 3RK1901-1DG22-1AA0 is a Twin data decoupling module in the SlimLine S22.5 form factor, designed to sit in an IP20 control cabinet on 35-mm DIN rail or wall-mounted with plug-in flaps. It decouples AS-Interface data and power for two AS-i segments, supplying up to 4 A DC at 24 V from a 21–32 V DC input bus, with a total supplied active power of 240 W. The module handles both grounded and non-grounded AS-i networks, includes ground fault detection, and supports AS-i Power24V. Its electronic short-circuit protection and output short-circuit proof design mean you don't swap fuses on a fault — the module recovers when the overload clears.
Rated input voltage is 21–32 V DC, drawing up to 8.2 A at the maximum input. The two AS-Interface outputs each carry up to 4 A DC total — that's the combined budget for both segments, not per-output. If you're powering a string of AS-i modules and actuators, the 240 W supplied active power sets the hard ceiling for your segment load. The signaling contacts are rated 3 A at AC-15 (24 V) and 1 A at DC-13 (24 V). AC-15 covers solenoid valve loads typical in packaging lines; DC-13 covers DC inductive loads like contactor coils. The ambient temperature range of -25 to +70 °C means it can live in a non-conditioned cabinet on a hot factory floor, but mount it vertically per the spec — horizontal mounting isn't listed as acceptable. Wire termination accepts 2x (0.25... 1.5 mm²) solid or with core-end processing, or 2x (24... 16 AWG). The spring-cage terminals on the SlimLine S22.5 body are tool-less — strip to 8 mm and push. The 22.5 mm width per module stacks efficiently on the DIN rail; depth is 121.2 mm, height 104.9 mm.
Safety and AS-Interface specifics
This module is marked suitable for use in safety-related circuits. It includes a test function for the signaling contacts, external reset capability, and a sequential connected time-delay function — useful when you need staggered restart after a safety event. The LED status display gives a quick visual on segment health and faults. The AS-Interface protocol is supported natively, with data decoupling integrated. No external filter or decoupling block needed between segments. The module works on both grounded and non-grounded AS-i networks, so it adapts to the plant's grounding philosophy without hardware changes.