DALI (Digital Addressable Lighting Interface) is a two-wire digital bus that replaces phase dimming. Each driver has its own address, enabling individual dimming, software scenes and sensor integration without re-cabling circuits.

One DALI line carries up to 64 addresses, 16 groups and 16 scenes. DALI-2 (since 2014) adds certified sensors, controllers and standard device types such as Tunable White (DT8).

DALI is non-polarised, two-wire, can share a 5-core cable with 230 V (typical install) and runs up to ~300 m at 1.5 mm². A DALI PSU delivers 16 V DC at up to 250 mA per line.

Versus phase dimming, a DALI driver receives a digital command (0–254) rather than reduced voltage. The result is flicker-free dimming with no interference between fittings. The logarithmic curve matches eye perception — 50 % on the bus reads as ~25 % brightness.

DALI-2 D4i adds internal sensor power and data reporting (energy, runtime) — the foundation for intelligent office and Smart home systems.

Practical applications

Residential (Penthouse, villas)

Makes sense from ~6–8 controlled fittings up — scenes Morning, Movie, Guests, Night with CCT (DT8) and layering changes.

Hospitality (hotels, Fine dining)

DALI-2 is standard for hotel rooms and restaurants; subtle dimming toward candle-like dusk in Fine dining.

Offices

DALI-2 + D4i presence and daylight sensors optimise energy; DT8 is required for biodynamic scenarios.

Retail & Showroom

Addressable dimming enables different scenes for different days; accent:ambient ratios of 5:1 to 15:1.

Architecture & façades

DALI also serves exterior and façade lighting with time-of-day scenes and daylight sensing.

Advantages

Every fitting individually addressable regardless of wiring
Smooth dimming from 1 to 100 % without flicker
Open standard (IEC 62386) — vendor-neutral
Software-defined scenes, no rewiring to change them
Integrates with sensors, switches and BMS / Smart home upstream

Limitations

Higher up-front cost for drivers and controller
Requires planning and commissioning
Overkill for small installs of 1–4 fittings
Cannot mix DALI and phase dimming on the same line

Recommendations

Plan the DALI bus during electrical engineering
Specify DALI-2 (D4i) drivers — backwards compatible and future-proof
For Tunable White use DT8 — one address, full CCT and intensity control
Design scenes around client rituals, not rooms
Always plan physical switches as a fallback

Common mistakes

Bolting DALI on later without the cabling in place
Mixing DALI and phase dimming on the same line
App-only with no physical switches
Drivers installed but no scenes programmed
Cheap non-certified DALI drivers misbehaving on broadcast

In summary

DALI and DALI-2 are today's standard for serious architectural lighting. Overkill in tiny installs, but from a larger apartment, boutique hotel or office upwards they offer the best mix of flexibility, dim quality and future-proofing.