ABB RM/S3.1 is the ABB i-bus® KNX Room Master, MDRC. It controls apartment areas, typically in hotels and small apartments, through 12 inputs and eight configurable outputs.

ETS-programmable switching and shutter model. Its outputs can be used as four switching plus four shutter outputs, or as eight switching outputs.

Integrated Room Functions

• Inputs: 12 binary inputs.
• Outputs: 4 switching + 4 shutter outputs, or 8 switching outputs.
• Local operation: Supported.
• KNX integration: The Room Master is a complete KNX TP DIN-rail device, not a plug-in module for the RC/A Room Controller.

Model Selection

Room Master variants have materially different input/output layouts and application concepts. Select the exact RM/S3.1 type for the required room functions; terminals, channel counts and application parameters must not be inferred from another RM/S model.

At a Glance

Specification	Detail
Catalog description	Room Master, MDRC
Order code	RM/S3.1 (2CDG110165R0011)
EAN	4016779881067
Inputs	12 binary inputs
Outputs	4 switching + 4 shutter outputs, or 8 switching outputs
Maximum switching current	20 A
Output voltage	230 V AC
Power loss	5.15 W
Dimensions (H × W × D)	90 × 216 × 64.5 mm
DIN-rail width	12 modules
Net weight	0.55 kg
Protection	IP20

Planning, Installation and Commissioning

Install the MDRC device on 35 mm DIN rail in a suitable distribution enclosure. Installation and commissioning must be performed by a qualified electrician. Isolate hazardous voltages before wiring, keep KNX SELV conductors separated from mains circuits, and follow the type-specific ABB wiring diagram and instructions.

Use only the documents listed below for RM/S3.1. ABB does not currently expose a confirmed standalone ETS package for this model, so no guessed or legacy application download is presented.