Description
Introduction
The ABB i-bus® KNX Line Coupler LK/S 4.3, SKU LK/S4.3, is a modular installation device for KNX system topology. It is designed for use as a line coupler, area coupler, or, from ETS 6, as a segment coupler for connecting line segments with each other including filter function.

In KNX projects, the ABB LK/S4.3 supports electrical isolation between connected KNX lines or areas and supports extended frames from greater than ETS5. It also supports KNX Data Secure communication, allowing telegrams to be processed, filtered, forwarded, or blocked depending on settings.
Key Features
- Brand: ABB.
- SKU: LK/S4.3.
- Extended Product Type: LK/S 4.3.
- Product ID: 2CDG110310R0011.
- Catalog Description: LK/S4.3 Line Coupler Secure, MDRC.
- Compatible Bus Systems: KNX (TP).
- Security Standard: KNX Data Secure.
- Degree of Protection: IP20.
Benefits
- Supports multiple topology roles: line coupler, area coupler, and segment coupler from ETS 6.
- Provides electrical isolation when connecting a line with a main line or a main line with an area line.
- Supports KNX Data Secure communication for secure KNX installations.
- Processes, filters, forwards, or blocks KNX Data Secure telegrams depending on settings.
- Acts as a Secure Proxy by encrypting or decrypting telegrams with group addresses in both directions between plain and secure communication.
- Supports extended frames from greater than ETS5 for modern KNX project requirements.
- Specified as a modular installation device with a module width of 2 space units.
Technical Specifications
Applications
- Line coupling in KNX systems, connecting a line with a main line.
- Area coupling in KNX systems, connecting a main line with an area line.
- Segment coupling from ETS 6, connecting line segments with each other including filter function.
- KNX installations requiring filtering, forwarding, blocking, encryption, or decryption behavior based on project settings.
Installation Notes
- Use the ABB LK/S4.3 only in accordance with the official ABB product documentation and the project’s ETS configuration requirements.
- Confirm whether the project requires line coupler, area coupler, or ETS 6 segment coupler functionality before ordering and commissioning.
- Match the exact SKU LK/S4.3 and Product ID 2CDG110310R0011 against the BOQ, panel schedule, and KNX topology design to avoid wrong orders.
- For documentation control, reference Instructions and Manuals document number 2CDG941270P0001 and Declaration of Conformity – CE document number 9AKK108469A3392.
- Manual Operation is listed as No, so commissioning and project behavior should be planned through the supported KNX/ETS configuration process rather than local manual operation.
Developer Resources
- Manufacturer product page: https://new.abb.com/products/2CDG110310R0011/lk-s-4-3.
- KNXbazzar category page: https://knxbazzar.com/product-category/knx-system-components/.
- ABB brand page on KNXbazzar: https://knxbazzar.com/knxshop/?brand=abb.
- Instructions and Manuals reference: 2CDG941270P0001.
- Declaration of Conformity – CE reference: 9AKK108469A3392.
- EAN: 4016779138819.
- ETIM 9 and ETIM 10 classification: EC000673 – Area/line coupler for bus system.
FAQ
What is the ABB LK/S4.3 used for?
The ABB LK/S4.3 is used as a KNX line coupler, area coupler, or, from ETS 6, as a segment coupler for connecting line segments with each other including filter function.
Does the ABB LK/S4.3 support KNX Data Secure?
Yes. The listed security standard is KNX Data Secure. KNX Data Secure telegrams are processed, filtered, forwarded, or blocked depending on settings.
Can the ABB LK/S4.3 work as a Secure Proxy?
Yes. As Secure Proxy, it encrypts or decrypts telegrams with group addresses in both directions between plain and secure communication.
Which bus system is listed for this product?
The compatible bus system listed for the ABB LK/S4.3 is KNX (TP).
What should buyers verify before ordering?
Buyers should verify the exact SKU LK/S4.3, Extended Product Type LK/S 4.3, Product ID 2CDG110310R0011, and the required coupler role against the BOQ, ETS design, and official ABB documentation.
What is the exact product model?
The order/model code for this page is LK/S4.3. Match it against project documents before purchase.
Conclusion
The ABB LK/S4.3 is a KNX Line Coupler Secure, MDRC device for structured KNX topology, supporting use as a line coupler, area coupler, and from ETS 6 as a segment coupler.
For professional procurement, verify the exact SKU LK/S4.3, ABB Product ID 2CDG110310R0011, KNX Data Secure requirements, and official documentation references before ordering.











Reviews
There are no reviews yet.