The ABB USB/S 1.2 KNX USB Interface (order code 2CDG110243R0011) is an MDRC Pro M device that connects a PC to the KNX twisted-pair bus for ETS programming, bus monitoring, group monitoring and visualisation / other USB clients. Install it on a 35 mm DIN rail in the distribution board next to the bus supply so commissioning can be done at the panel without relying on a remote IP interface.

USB/S 1.2 is the long-frame successor to USB/S 1.1. It supports a maximum APDU length of 55, so ETS can use longer telegrams for faster application downloads and for programming KNX Data Secure devices. Standard short frames remain limited to 15 bytes of payload; long frames are required when the target device (and every coupler between the USB interface and that device) supports them — ETS from ETS5 detects this automatically.

Connect the PC with a USB 1.1 Type B cable (max. 5 m). On Windows the driver installs on first connection; select the interface under ETS Found Interfaces. ABB states that a dedicated ETS application is not required for basic use; use the ABB-published USB/S 1.2 driver / software package from Downloads when prompted. KNX and USB sides are galvanically isolated. Bus supply is from the KNX line (21…30 V DC); USB side draws 5 V from the host.

Key Features — Local Commissioning Interface

• USB ↔ KNX TP: Programming, bus monitor and group monitor for ETS and visualisation clients.
• Long frames (APDU up to 55): Faster downloads and required path for KNX Secure device programming versus USB/S 1.1.
• Galvanic isolation: Separates the PC USB domain from the KNX bus.
• Status LEDs: Indicate operating state and telegram traffic (plus KNX programming LED per ABB literature).
• MDRC 2 MW: Compact Pro M housing, approx. 90 × 36 × 63.5 mm (H × W × D), IP20, net weight approx. 0.08 kg.
• Panel workflow: Prefer USB/S 1.2 for on-site work; use IPS/S3.1.1 / IPS/S3.5.1 when remote KNXnet/IP tunneling is needed.

At a Glance

Specification	Detail
Product type	KNX USB Interface, MDRC (long-frame capable)
Order code	USB/S1.2 (2CDG110243R0011)
EAN	4016779064507
Host / bus	USB 1.1 Type B ↔ KNX TP
Long frames	Yes — max. APDU length 55
Supply	KNX 21…30 V DC; USB 5 V DC from host
Width / dimensions	2 MW; approx. 90 × 36 × 63.5 mm (H × W × D)
Protection	IP20; protection class II

Full ratings, wiring and LED behaviour are in the ABB technical data and installation instructions under Downloads. Prefer USB/S 1.2 over legacy USB interfaces whenever long frames or current Secure projects are required.