DALI is fast
A common question about DALI is regarding its speed as there are some misconceptions regarding it. The fact is that when used correctly DALI is in fact fast.
Firstly, the baud rate of DALI is slower than the baud rate of protocols like DMX. However, DMX needs to be fast as it is a channel based system, while DALI is a group based system. This means that if a command needed to communicate to turn the lighting on for a room of 20 light fittings using DMX would send 20 separate commands, while DALI would only require to send one command. In this instance, DMX would need to be 20x faster to turn on the same 20 light fittings within the same period of time.
Secondly DALI can send up to 50 commands per second. Considering that each DALI line has only a maximum of 64 devices attached and that each line in a building runs in parallel, this effectively means that its 50 commands per second for each DALI line in the building.
EXAMPLE: 64 light fittings on a DALI line are part of 16 different rooms, each room could turn on, off and back on again (all 16 rooms individually) in less than 1 second.
Why would you use DMX?
DMX is better suited to show or entertainment lighting, but not commercial lighting. In show or entertainment lighting, each light fitting is required to be more dynamic as its control is channel based. Some control manufacturers would like to use DMX as their previous approaches (ie 1-10V and DSI systems) are also channel based systems and therefore their control implementation in the past was channel based, not group based.
DALI is better suited to full control solutions, such as fluorescent ballasts, LED controllers, emergency, switches, sensors, relays etc; and is supported by all major lighting manufacturers, whereas DMX has a limited range for commercial lighting.