DALI is the global standard for digital lighting control in commercial buildings. It replaced analogue dimming systems that could only control entire circuits, not individual fittings. With DALI, every luminaire gets its own address. You control each one independently or in any combination of groups and scenes. The protocol is open, interoperable, and built for the long term.
How DALI Works
DALI uses a two-wire bus carrying digital commands at 1200 baud. The bus runs alongside the mains power cabling with no polarity requirement. Each bus supports up to 64 individual addresses, 16 groups, and 16 scenes. Multiple buses connect to a DALI controller or gateway for larger installations. The bus voltage is 16V DC nominal, carrying negligible current. It cannot be confused with mains and presents no shock risk.
DALI vs DALI-2
The original DALI standard (IEC 62386 Part 101/102) covered basic dimming and switching. DALI-2 (Parts 103/104) adds mandatory verification testing for interoperability, input devices (sensors and switches) as addressable bus participants, colour control (Tc and RGBW), standardised diagnostics, and energy reporting. Always specify DALI-2 compliant drivers for new installations. They are backwards-compatible with original DALI systems.
Addressing and Groups
During commissioning, each driver receives a unique short address (0-63). Addresses can then be assigned to one or more of 16 groups. A single command to Group 3 dims every fitting in that group simultaneously. Scenes store pre-set combinations: Scene 1 might set the open plan area to 80%, perimeter to 40%, and meeting rooms off. Recall the scene with one command.
Daylight Harvesting
DALI sensors measure ambient daylight and feed the data back to the controller. As natural light increases, the system reduces artificial output proportionally. The result is maintained illuminance at the working plane regardless of time of day or weather conditions. Energy savings of 30% to 60% are typical in perimeter zones with good glazing. The system dims so gradually that occupants rarely notice the adjustment.
Occupancy Sensing
PIR and microwave presence sensors connect as DALI-2 input devices. Unoccupied areas dim to a background level or switch off entirely after a configurable timeout. Combined with daylight harvesting, occupancy sensing delivers the full energy reduction potential. Office installations combining both strategies routinely achieve 50% to 70% energy savings versus static lighting.
Integration with BMS
DALI gateways interface with building management systems via BACnet, Modbus, KNX, or IP. The BMS provides higher-level automation: time scheduling, alarm management, energy monitoring, and integration with HVAC and blinds. DALI handles the luminaire-level control. The BMS handles building-level strategy. Together they deliver intelligent, responsive environments.
Wiring Considerations
DALI bus wiring uses standard 1.5mm twin cable. Maximum bus length depends on cable resistance, typically 300 metres with 1.5mm cable. No termination resistors required. The bus is topology-independent: star, daisy-chain, tree, or any combination. This flexibility simplifies installation compared to point-to-point analogue wiring. Power to the bus comes from the DALI controller or a dedicated bus supply.
Commissioning
DALI commissioning assigns addresses, creates groups, programs scenes, and configures sensor parameters. Modern systems use tablet-based commissioning apps that identify each fitting by flashing it, then drag-and-drop it into groups. Initial commissioning typically takes 2 to 4 hours for a standard office floor. Changes after handover (moving desks, reorganising teams) require only group reassignment, not rewiring.
Maintenance and Diagnostics
DALI-2 drivers report lamp failures, power consumption, and operating hours back to the controller. Building managers see which fittings need replacement before tenants complain. Predictive maintenance scheduling based on actual operating hours extends replacement intervals and reduces disruption. The system logs fault history for compliance records and lifecycle planning.
Cost Justification
DALI adds approximately 8% to 12% to the electrical installation cost compared to basic switched circuits. Energy savings of 50% or more deliver payback within 2 to 4 years on most commercial projects. Beyond energy, the flexibility to reconfigure without rewiring saves substantial refurbishment costs over the building lifecycle. Most BREEAM and WELL certifications require addressable lighting control as a baseline.
All EMPRICS commercial luminaires are available with DALI-2 compatible drivers. Our technical team supports control system design and commissioning coordination. Contact projects@emprics.com for specification support.