DALI — Digital Addressable Lighting Interface — is the industry standard that lets every light fitting in a building act as its own smart device. Instead of switching whole circuits on and off, DALI gives each fixture a unique address, so it can be dimmed, grouped, scheduled and diagnosed individually over a simple two-wire bus. It's an open standard defined by IEC 62386, which means fittings, sensors and controllers from different manufacturers can work together on the same system.

How DALI compares to older control methods

Traditional 0-10V dimming controls a whole circuit at once and offers no feedback — if a fixture fails, nobody knows until someone notices a dark room. DMX, common in theatrical and stage lighting, sends one-way commands and wasn't built for building-wide automation. KNX handles whole-building automation but is a heavier, more general-purpose protocol. DALI sits in between: purpose-built for lighting, bidirectional (so it reports faults and status back), and light enough to install fixture-by-fixture without rewiring a building's power circuits.

How a DALI system is put together

A DALI installation is built from a small set of parts:

Controller — the command centre, ranging from a small standalone unit for a single space to a networked or cloud-based controller for an entire building.
Ballasts and LED drivers — regulate power to each fitting and report status back over the bus.
Sensors and switches — occupancy, daylight and temperature sensors, plus programmable wall switches, that trigger scenes and automation.
Power supply — a single 16V DC supply feeds the bus, rated to a maximum of 250mA.
Fixtures — each one addressable individually, from 0 to 63 per bus line, and organised into up to 16 groups.

All of this communicates over one two-core cable that carries both power and data — no separate dimming wires, no extra circuits per zone. A typical run uses 1.5mm² cable up to 300 metres, which is a fraction of the cabling a traditional multi-circuit lighting layout needs.

DALI controller, sensor, and LED driver hardware components

Single-master vs multi-master systems

Smaller installations typically run single-master — one control point manages the whole bus, which suits a single room, tenancy or small building. Larger sites use multi-master configurations, with multiple controllers and interfaces coordinating across zones, floors or buildings.

What DALI actually does once it's installed

Because every fitting has its own address, DALI supports capabilities that switch-based lighting simply can't:

Flicker-free dimming from 0-100%, with linear or logarithmic curves depending on the space.
Tunable white — shifting colour temperature from around 2700K to 6500K to support circadian rhythm, keeping spaces brighter and cooler during the day and warmer in the evening.
Scenes — pre-programmed lighting states (a "Meeting Mode", a "Relax Mode", a "Retail Display Mode") triggered by a single switch, sensor, or app command.
Scheduling — automated time-of-day changes without anyone touching a switch.
Emergency lighting — DALI-connected emergency fittings can self-test and report faults automatically, keeping installations compliant with EN 50172 and IEC 62034 without manual testing rounds.

Tunable white and colour dimming on an architectural facade lighting install

Connecting DALI into the wider smart building

DALI doesn't have to sit on its own. It integrates with:

IoT platforms — cloud control from a smartphone, voice control through Alexa or Google Assistant, and AI-driven optimisation that learns occupancy patterns over time.
Building management systems — via BACnet, KNX or Modbus, so lighting sits alongside HVAC, security and other building systems in one control layer. This is exactly the kind of integration HASSAR.AI is built to coordinate at the smart-home scale.
Wireless DALI+ — the newer generation that drops the physical bus wiring entirely, running instead over Wi-Fi, Bluetooth or Thread. It's backward-compatible with existing DALI-2 gear, which makes it a practical option for retrofits where running new cable isn't feasible.

DALI to KNX and BACnet building management system integration diagram

Installing and maintaining a DALI system

A typical rollout follows a clear sequence:

Plan the scope — device count, zoning, wiring pathways, power budget, and component compatibility.
Install the 16V DC supply and run the two-core bus wiring.
Mount controllers, sensors and switches.
Address every device individually (0-63) and organise them into groups and scenes.
Run diagnostics to confirm every fixture reports back correctly.

Commissioning tools such as Helvar Designer, Philips DALItool and Tridonic masterCONFIGURATOR are used to assign addresses, define scenes, set schedules, calibrate sensors and monitor energy use. Ongoing maintenance is light — periodic log review, power supply checks, sensor recalibration, and firmware updates as spaces get reconfigured over time.

Common issues and how they're resolved

Unresponsive fixtures — rescan bus addresses.
Flickering — check the power supply and keep DALI wiring separated from high-voltage cabling.
Dimming not working — confirm DALI-2 compatible drivers and check the configured dimming curve.
System lag — keep device counts within the 64-per-line limit and segment large installations properly.
Sensor faults — reposition and recalibrate the sensor's detection range.

Common DALI lighting challenges and solutions on a commercial building

Where DALI gets used

DALI-controlled office lighting and wall-mounted touch panel

Commercial buildings pair daylight harvesting with occupancy sensors to cut lighting energy use by up to 60%, while tunable white improves focus in office environments and BMS integration centralises monitoring across a whole site.

Industrial and warehouse environments use motion-controlled high-bay fittings with adaptive brightness, zonal dimming for active work areas, and compliant emergency lighting — often paired with cloud-based remote monitoring across a large floor plan.

Smart homes get voice control, custom scenes, sensor-based dimming and full smartphone access, with tunable white supporting a healthier day-night lighting rhythm.

Healthcare and hospitality settings lean on the same flexibility differently — cool daylight tones keep hospital staff alert, warmer evening tones support patient recovery, and automated emergency-light testing keeps facilities compliant without manual checks. Hotels commonly report better guest satisfaction and lower running costs from motion-sensing hallway lighting and guest-configurable room scenes.

DALI lighting across office, industrial, hospitality, smart home and hotel lobby applications

Frequently asked questions

How is DALI different from a normal dimmer? A standard dimmer controls a whole circuit. DALI addresses each fixture individually and reports its status back, so you get per-fitting control and diagnostics instead of an all-or-nothing circuit.

Is DALI suitable for a home, or only commercial buildings? Both. The same addressing and scene logic that runs an office floor scales down cleanly to a house, particularly when paired with a smart home hub.

How much energy does it actually save? Daylight harvesting and occupancy-based dimming commonly cut lighting energy use by around 60% in commercial spaces, mostly by turning off or dimming lights nobody's using.

What's the difference between DALI-1 and DALI-2? DALI-1 (1990s-2014) supports basic addressing with limited feedback. DALI-2 (2014-present) adds multi-master operation, richer diagnostics, and formal certification for interoperability between manufacturers.

Does DALI work with Alexa or Google Assistant? Yes, through a compatible controller or gateway that bridges the DALI bus to those platforms.

What does wireless DALI+ add? It removes the physical bus cabling, running instead over Wi-Fi, Bluetooth or Thread, while staying backward-compatible with existing DALI-2 fixtures — useful for retrofits.

How many devices can one DALI line support? Up to 64 individually addressed devices, organised into as many as 16 groups.

The bottom line

DALI turns a lighting system from a set of dumb circuits into a network of individually controllable, self-reporting devices. At ACAI, we design and install DALI systems that integrate cleanly with HASSAR.AI and the rest of your smart electrical and energy setup — so lighting isn't a separate system bolted on, it's part of one intelligent home.