The Siemens 3RK1901-1DG12-1AA0 is a single data decoupling module from the SlimLine S22.5 series, designed to sit inside an IP20 control cabinet. Its job is to decouple the AS-Interface data signal from the 24V DC power supply on the AS-i network, preventing the power supply from loading the data line and ensuring clean communication between the AS-i master and slaves. It supplies up to 120W of active power to the AS-i segment, drawing a maximum of 4.1A at the input and delivering up to 4A at the output, both at the rated 21-32V DC range. The module includes ground fault detection and is suitable for both grounded and non-grounded AS-i networks, with an electronic short-circuit protection design and an output that is short-circuit proof. For control signal switching, the auxiliary contacts are rated at 3A at AC-15 at 24V and 1A at DC-13 at 24V — these ratings govern the inductive load switching capability for signaling and interlocking circuits, not the AS-i power path.
The module mounts on a standard 35-mm DIN rail or can be wall-mounted using the plug-in flaps. It occupies a single 22.5mm width slot — the SlimLine S22.5 footprint — and must be installed in a vertical orientation. The 121.2mm depth is the dimension to check for enclosure clearance, especially if the backplane has deep wiring ducts or a second row of terminals. Wiring connections accept 2x (0.25... 1.5 mm²) solid or stranded conductors with or without core-end processing, or 2x (24... 16) AWG. Strip length and ferrule sizing follow standard practice for spring-cage terminals in this class. The module is suitable for use in safety-related circuits, with a test function for signaling contacts and an LED status display. It does not support auto-reset or sequential connected time-delay, but does accept an external reset signal.
The closest functional second-source question comes up — the 3RT1036-1AB00 is a contactor, not a data decoupling module. It will not drop into this panel position or perform the same function. The 3RK1901-1DG12-1AA0 is the correct part for AS-i data decoupling; no rewiring or substitution is possible with a contactor.
The module operates over an ambient temperature range of -25 to +70°C, which covers most control cabinet environments including unheated enclosures.