A KNX TP1 line may be divided into a maximum of 4 physical segments, each of 64 devices, giving 256 devices per logical line.

The multi-segment architecture relies on Line Repeaters: 4 x 64 = 256 devices, all sharing the same logical line and the same line address Z.L. Each segment still requires its own PSU and choke, and the repeater regenerates the bus signal between segments. From ETS and addressing perspectives, all 256 devices appear under the same line, with individual addresses Z.L.1 to Z.L.255.

Multi-segment lines complicate troubleshooting — when possible, prefer to split the project into two normal lines coupled through a Line Coupler rather than chaining repeaters on a single overloaded line.