What is DALI and why is it important?

What is DALI in Lighting Control and Why is it Important?

In today's smart buildings, lighting means much more than simply turning lights on and off. This is where DALI comes in. So, what exactly is this DALI technology that lighting professionals frequently talk about?

What is DALI?

DALI stands for "Digital Addressable Lighting Interface." In its simplest terms, it is a bidirectional communication protocol that enables lighting components (drivers, sensors, switches) to communicate with and be controlled by each other. Emerging in the late 1990s, this technology has become much more advanced and reliable with the current DALI-2 version (IEC62386 standard).

Why Choose DALI-2?

Older DALI versions could have compatibility issues between brands. However, DALI-2, managed by DiiA (Digital Illumination Interface Alliance), eliminated this problem by introducing mandatory certification processes. This means you can confidently use products from different brands that bear the DALI-2 logo on the same system.

Key Advantages of DALI:

• Digital Precision: Unlike analog systems, DALI is digital. You can control the light level with 1% precision and without flicker.
• Addressability: Each luminaire has its own "identity". This allows you to create groups or change scenarios via software without changing the cabling.
• Simple Installation: No special shielded cables are required. Power and control lines can be routed within the same cable bundle.
• Flexible Topology: Cabling can be done in star, tree, or line configurations (excluding loop/ring).

Differences Between DALI and 1-10V: Why Digital?

While the 1-10V analog system is frequently compared in the industry, DALI is completely digital. We can summarize the difference as follows:
1. Communication: 1-10V can only say "turn off" or "turn on". DALI, on the other hand, can manage complex commands such as color changes, emergency lighting tests, and fault feedback.
2. Standard: In 1-10V systems, the dimming curve is not standardized; light levels may be inconsistent with different driver brands. In DALI, however, the dimming curve is standardized, and every device responds to the same command in the same way.
3. Flexibility: When your office layout changes, you need to disconnect and reconnect cables in a 1-10V system. With DALI, you can change which switch controls which light with a single click.

DALI and Building Automation Systems (KNX, LON, BACnet)

Another frequently asked question is: "I already have KNX in my building, why should I use DALI?"
KNX, LON, or BACnet are protocols designed for the overall management of a building (Heating, Elevators, Security). However, these protocols are cumbersome for directly connecting to LED drivers, and it is difficult to find suitable drivers on the market. Ideal Scenario: KNX or BACnet handles the building's overall management (BMS), while DALI takes on specific and sensitive tasks such as lighting. These two systems communicate via a "Gateway". For example, when the security system (KNX) detects a burglar, it can send a command to the DALI system to turn on all the corridor lights.

Technical Overview: How Does DALI Work?

The heart of the DALI system is a two-wire bus line. The system consists of the following components:
1. Bus Power Supply (PSU): Maintains the voltage of the line (approximately 16V).
2. Application Controller: The brain of the system. It processes data from sensors and sends commands to drivers. Manages traffic conflicts. 3. Input Devices: Sensors and switches.
4. Control Gears (LED Drivers): Devices that receive the command and turn on the light.

Important Wiring Tips:

• Voltage: The DALI cable operates at approximately 16V DC, but it is not classified as SELV (Low Voltage). Therefore, cables suitable for the mains voltage (220V) should always be used.
• Polarity: DALI is not polarity sensitive. The system will work even if you connect the cables upside down.
• Cable Type: Generally, 5-core (Phase, Neutral, Ground + DC, DC) cables are used.
• Range and Speed: The data rate is low (1200 baud), making the system very resistant to electrical interference. No shielding is required.

In summary,
DALI is a global standard in lighting control. The guaranteed compatibility, precise control, and ease of installation, especially with DALI-2, make it indispensable for modern buildings. If you are looking for flexibility and intelligent management in your project, DALI is the right solution.