You are now in a digital world!
DALI is a digital signal that makes the data transmission less susceptible to
errors due to noise and attenuation, thus making the performance better than the analog
transmission signal. Unlike 0-10V analog system, the DALI system has
the bi-directional communication capability that can allow the controller to
obtain the feedback from the luminaires and devices when queried.
Furthermore, the digital nature of DALI signal can be integrated
smoothly with other Wi-Fi mobile devices (such as Android smartphone, iPhone, Tablet, Android enhanced smart TV or DaliTV
box, Android Wear watch) and Windows PC.
Control and Feedback
Luminaires are controlled through a broad range of queries/commands, which
are illustrated by IEC62386 including the followings.
- Turn on/off
- Dim up/down
- Lamp status (faulty, working, running hours)
- Device Status
- Set features such as Power_on_level, and System_Failure_level
Because each luminaire/device is given its own unique address,
its instant feedback when queried can help to minimize the maintenance costs of the system. Also, the individual
control of each luminaire/device facilitates the concepts of Scenes and Groups
for a more efficient and effective control of the lighting system.
Scene is a setting, which allows for
one or more luminaires to be controlled together and set to predetermined
levels. For example in a meeting room, the user may want the luminaires to have
different settings for different tasks (like, meeting, presentation, video
presentation, and lunch)
There are 16 different scenes available for each DALI bus. When a scene
command is sent across the DALI bus, every luminaire/device receives the command
and checks its memory accordingly. If the luminaire/device has a stored action,
the programmed action will be carried out, otherwise the command will be
The concept of Group is to allow multiple luminaires/devices on the same DALI bus
to be grouped together, so that the grouped luminaires/devices can perform an action together.
Each luminaire/device can be assigned the membership to a
group or multiple groups. For instance, if the user wants to turn on 25 luminaires in one room belonged to the same group, one single DALI command can do the
job. Unlike channel-based system, 25 individual commands need to be
issued. Thus it will be 25 times slower than the DALI system, and
sometimes the luminaires can be seen to turn on one by one.
Functionality and Flexibility
Each luminaire/device has its own microcontroller (MCU) on board, thus making
them possible to be turn ON/OFF directly by the DALI control system
rather than using a mains switch. This brings greater functionally and allows
for flexibility and change after installation. Moreover, changes can be made to scenes
and functions through simple programming without the addition of any new hardware.