DALI Basics: Addresses and Groups
A DALI segment manages up to 64 participants (ECGs), addressed with short addresses 0–63. Commissioning is done via automatic addressing in a DALI commissioning tool or directly via ETS when the gateway supports DALI configuration.
DALI supports 16 groups (independent of short addresses). One ECG can belong to multiple groups. Scenes (0–15) store light values directly in the ECG, a scene recall requires only a single telegram instead of one per luminaire.
Bus voltage on the DALI segment (9.5–22.5 V DC, max. 250 mA) is supplied either by the gateway or an external DALI power supply. Cable length up to 300 m, unshielded two-core cable is sufficient.
DALI-KNX Gateway: Integration into KNX System
The gateway is installed in the distribution board (DIN rail mounting) and connects the KNX TP bus to the DALI segment. It provides separate COs for each DALI address, group and scene: e.g. CO for switching (DPT 1.001), relative dimming (DPT 3.007), absolute brightness (DPT 5.001) and status feedback.
Manufacturers such as Theben, Zennio and MDT offer gateways with 1–4 independent DALI segments. For larger installations, multiple gateways can operate in parallel, each segment is electrically isolated.
A key advantage over 1–10V dimmer actuators: DALI provides feedback on actual lamp status (operating, fault, lamp failure). Error diagnosis is therefore possible at individual ECG level.
Key Facts
- Up to 64 ECGs per DALI segment, 16 groups, 16 scenes
- Scenes stored in ECG, no telegram per luminaire
- Status feedback and fault diagnostics at luminaire level
- DALI cable: unshielded, two-core, up to 300 m
- Gateway manufacturers: Theben, Zennio, MDT, LÜTZE