The emergency lighting of a building CANNOT be driven by KNX alone: it must comply with dedicated standards (NF EN 1838, EN 50172) that require a self-contained system with a backup battery.

A self-contained emergency luminaire is a regulatory obligation: it has a local battery and operates without either mains supply or bus communication. KNX can supplement it with test/diagnostic functions or with the normal switching command (self-contained luminaires light up when the 230 V supply fails), but it must NEVER replace the autonomous emergency system. This is a classic exam topic for tertiary projects.

Document the regulatory boundary clearly in the project file — many disputes arise from clients assuming "KNX controls everything", including life-safety circuits that legally cannot be on KNX.