Modern lighting systems are no longer limited to turning a lamp on or off. Today’s buildings are looking for flexibility, visual comfort and energy efficiency. It is against this backdrop that the DALI protocol has established itself as an essential standard. But what does a DALI driver actually do? How does it work, and why has it become a standard for controlling LED luminaires?
What is a DALI driver?
A DALI driver is an LED power supply capable of receiving and sending digital instructions via the DALI(Digital Addressable Lighting Interface) protocol. It converts the electrical current required by the LEDs while ensuring bidirectional communication with a central controller.
In practical terms, this means that each luminaire equipped with a DALI driver can be identified, controlled, monitored and integrated into a lighting scenario without the need for complex wiring.
The basic principle
The DALI protocol is based on a digital communication line running parallel to the power supply. Each driver is assigned a unique address (up to 64 addresses per DALI line), making it possible to :
- control a luminaire individually ;
- create logical lighting groups (zones, rooms, corridors);
- program scenes and lighting transitions;
- receive status feedback (fault, current intensity, operating time, etc.).
The components of a DALI system
A DALI network is made up of a few essential elements:
- DALI drivers: electronic power supplies integrating the protocol.
- A DALI controller or gateway: interface that sends commands (via software, wall button, sensor or PLC).
- Luminaires or LED modules: electrically connected to the driver.
- The DALI bus: two communication wires without polarity, connected to all the drivers in the network.
Simple, universal communication
The great advantage of DALI is its standardisation (international standard IEC 62386). All compliant equipment is interoperable, whatever the brand. This means that an installation can be upgraded without depending on a single manufacturer.
Why choose a DALI driver?
High-end residential, commercial and architectural lighting projects use DALI for a number of reasons:
- Fine, stable dimming (1 to 100%) without flicker.
- Precise control of colour temperature(Tunable White).
- Creation of dynamic scenarios: ambience, energy saving, time management.
- Predictive maintenance: DALI drivers can signal an imminent breakdown or fault.
- Energy optimisation: presence and ambient light sensors can be integrated.
Differences between standard and DALI drivers
The major difference lies in communication. A standard driver simply delivers a constant current, without any interaction. A DALI driver, on the other hand, includes intelligent electronics capable of interpreting digital commands (intensity, switch-off, test, etc.).
| Criteria | Standard driver | DALI driver |
|---|---|---|
| Communication | None | Bidirectional digital |
| Dimming | Analogue (1-10 V or phase-cut) | Precise digital (1%) |
| Status feedback | No | Yes (diagnostics, faults, lifetime) |
| Interoperability | Limited | IEC 62386 standard |
Installation and wiring
The DALI bus consists of two additional wires (DA+ and DA-) connected to all the drivers in the circuit. It has no polarity, which simplifies wiring. A DALI line can be up to 300 m long, supply up to 64 addresses (drivers) and be extended via gateways.
A few best practices
- Use twisted pair cable (type 2×1.5 mm²) for the communication bus.
- Use a DALI controller compatible with the number of drivers to be addressed.
- Provide logical addressing (by room or by zone) to simplify management.
- Document the addressing scheme to facilitate maintenance.
Future developments : DALI-2 and D4i
In recent years, the protocol has evolved towards DALI-2, a more robust and interoperable version. It includes extended categories of devices: detectors, switches, light sensors, etc. DALI-2 ensures complete compatibility between certified manufacturers.
The D4i standard is an extension of DALI-2 designed for intelligent luminaires. It enables the management of consumption, maintenance and performance data to be integrated directly into the luminaire. D4i is used in particular for connected urban lighting andsmart buildings.
Common DALI applications
- Offices and open spaces with day/night scenarios and presence detection.
- Museums and galleries where each spotlight can be dimmed individually.
- Hotels and restaurants to create dynamic atmospheres.
- Public or industrial buildings with centralised management via BMS or KNX.
- Urban lighting and architectural façades with intelligent control.
To remember
- A DALI driver is a communicating LED power supply capable of receiving and sending digital commands.
- The DALI protocol enables precise, flexible and interoperable control of luminaires.
- The DALI-2 and D4i versions make the system even more intelligent and suitable for connected buildings.
The Rodalight team
