The Interra ITR901-1102 (manufacturer datasheet code ITS901-1102) is a KNX Line Coupler Secure that interconnects two KNX TP bus lines — main line and sub line — with galvanic isolation between them. Depending on configuration and individual address, it operates as a line coupler, area coupler or repeater (without telegram filtering). Filter tables from ETS reduce bus load for group-oriented traffic according to the device’s place in the topology.

The coupler supports long telegrams (datasheet: max APDU 233; description notes up to 240 bytes) and a configurable manual function activated by a single button press with automatic time-out. Manual mode can temporarily bypass filtering for commissioning — suppress device configuration from the subline, suppress individually addressed telegrams, monitor subline traffic, enable/disable group or physical filtering, optionally reduce retransmissions, and run integrated diagnostics. LEDs show operational, filtering and fault states.

Key Features — Secure Line / Area Coupler

• Main ↔ sub TP coupling: Galvanic isolation between two KNX TP lines.
• Line / area / repeater: Role selected by address and ETS application.
• Filter tables: Group and physically addressed telegram filtering.
• Manual commissioning aids: Temporary filter bypass and traffic tracing.
• Compact Secure housing: 90.7 × 17.8 × 61.7 mm (H × W × D); IP20; S-Mode.
• Low bus load: Approx. 5 mA / 3 mA on the two lines (Interra datasheet).

At a Glance

Specification	Detail
Smartanix / order SKU	ITR901-1102
Interra datasheet code	ITS901-1102
Function	KNX Line Coupler Secure (line / area / repeater)
Connections	KNX TP main line + KNX TP sub line
Current (approx.)	5 mA / 3 mA (datasheet line currents)
Max. APDU	233 (datasheet table)
Dimensions (H × W × D)	90.7 × 17.8 × 61.7 mm
Configuration	ETS (S-Mode)

Applications and Related Products

• Multi-line plants: Structure areas and lines, limit broadcast and cross-line group traffic.
• Standard (non-Secure) coupler: Interra also lists ITR901-0002 on the classic Line Coupler page — use the Secure coding when the project requires this Secure hardware.
• IP backbone: ITR902-0001 KNX IP Router for KNXnet/IP routing / tunnelling.
• USB commissioning: ITR901-0003 for ETS via USB on a TP segment.

Choosing and Commissioning

Assign a correct line-coupler (X.Y.0) or area-coupler (X.0.0) individual address in ETS. Download filter tables after topology changes. Use manual function only temporarily during commissioning. Mount in dry locations; connect both TP lines with standard KNX connectors. Full ratings are in the Datasheet; application behaviour is detailed in the linked Product Manual and .knxprod under Downloads. Note: Interra’s catalogue label for this Secure product is ITS901-1102; Smartanix lists it as ITR901-1102.