Digital Addressable Lighting Interface (DALI) is a digital system interface for the lighting management of building lighting. Switching power supplies, ballasts, lamps, LED luminaires and other lighting components can be electronically controlled individually or in groups via the addressable DALI interface. The DALI interface operates with its own protocol and bidirectional data exchange. This has the advantage that the user is informed about the status of the corresponding lamp after an executed action.
The protocol used in the DALI interface is an asynchronous protocol that operates at 1,200 bit/s. The voltage level on the galvanically isolated control line is 16 V. All lighting components can be digitally addressed individually via this protocol. Further advantages are digital processing and communication. Advantages that classic bus systems in building automation do not offer.
The basic concept is based on master- slave operation, where the user controls the lighting components via input commands. 64 slaves can be connected to one master station. The lighting components are connected via a 5-core cable, of which three lines are available for power supply and two for control purposes. The control lines can be used to control 64 DALI devices individually or together in 16 groups. The cable length can be up to 300 m.
DALI command sets optimized for lighting purposes are available for communication. These include lamp status messages such as: Lamp on, Lamp faulty or Lamp dimmed to a certain value. Each message transmitted via DALI consists of the address part and the command. The order of the devices is arbitrary and the DALI bus is self- addressing. Via a gateway, the DALI interface can be connected to a building management system and the European Installation Bus( EIB) or the LON bus.