The Weinzierl KNX USB Interface 312.1 (Art. 5501, Smartanix SKU W 312.1) is a 1 TE DIN-rail data interface between a PC/laptop and the KNX TP bus. It is used as an ETS programming interface and supports KNX Long Frames (max. APDU length 233) for faster downloads and for KNX Security. The USB-C port is galvanically isolated from the bus; three multicolour LEDs show USB, mode and KNX status.

Communication uses HID/cEMI. The device also embeds a full KNX stack with BAOS V2 for OEM/developer use (kDriveExpress SDK). Power is taken from USB (<15 mA) and the bus (<3 mA) — no separate PSU. For a portable stick form factor see 332 Stick; for RF media 340 Stick; for power+USB in one MDRC 367.

Key Features — 312.1 DIN USB

• ETS bus access: Programming / diagnostics with Long Frames for Secure projects.
• USB-C, galvanically isolated: Safe PC connection; max. USB cable 5 m.
• 1 TE MDRC: Permanent install in the distribution board.
• BAOS V2 / System B: Developer path beyond plain cEMI.
• 3 LEDs: USB, operating mode and KNX traffic/errors.
• Low draw: USB <15 mA · KNX <3 mA.

At a Glance

Specification	Detail
Order / Art.	W 312.1 · Art. 5501 · EAN 4260262775016
Medium	KNX TP · HID/cEMI · APDU 233
USB	Type C · galvanically isolated
Width	1 TE (18 mm) · ~40 g
Protection	IP20 · −5…+45 °C
ETS	ETS 5/6 database (see Downloads)

Applications and Related Products

• Panel commissioning port: Fixed USB-C access next to the KNX line.
• Field stick: 332 when you need a pocket USB-A tool.
• Line power: 365 / 366 DGS.

Choosing and Commissioning

Mount on DIN rail in dry interiors; connect KNX red/black and USB-C. The interface needs USB power to operate. Load the official ETS5/6 database from Downloads. Do not open the housing; install by a qualified electrician only.