DALI Power supplies should all work the same… or so we might think.
After all: the new DALI-2 standards set up the behaviour of a DALI power supply, and once certified everything should work fine. Right? Right?
Unfortunately, it’s not quite that simple.
The behaviour of a DALI line is determined by a range of factors:
- The length of a DALI line;
- The topology of the line (number of spurs going off, how long they are);
- Type of cable used; and
- The electrical properties of the Control Gear and Control Devices on the line.
Especially regarding the Control Gear and Control Devices on a line – the design of these products, along with the effect of the communication waveform and the line topology can sometimes cause strange effects or poor communication.
We would all like to think that DALI-2 solves these problems – and it certainly makes things better than the “wild west” of DALI-1.
Sometimes, all that is needed to deal with poor DALI communication is to use a better DALI Power Supply because: Actually – not all DALI Power Supplies are created equal.
DALI Waveform - Poor Quality DALI Power Supply
Oscilloscope picture of the DALI Communication Waveform - rising edge, when using a competitors poorly designed power supply.
Communication on this DALI line was not reliable.
DALI Waveform - High Quality DALI Power Supply
Oscilloscope picture of the DALI Communication Waveform - rising edge, when the poor quality DALI Power Supply is replaced by a RAPIX DALI-2 Power Supply. No Other changes were made.
After the power supply change, communication on this DALI line was reliable.