DALI is a well known commercial Lighting control protocol that can be used with or independent to KNX. DALI allows the addressing of individual ballasts in lines of 64 devices. For many years DALI has been a good solution for commercial projects but studies have questioned the cost benefit of using DALI and this is where KNX comes in.
Advantages of DALI
- Simple topology with no radial circuit requirements
- Requires less distribution board space
- Allows smooth dimming curves
Disadvantages of DALI
- Estimates vary between 50-100% increase in cost of DALI over traditional phase dimming
- DALI is not as simple to commission, test and fault find
- DALI products are not tested for conformity
- DALI is ‘send and forgot’ meaning there is no fail safe for a lost ‘telegram’ (command)
KNX offers the same functionality as DALI systems but without the need to individually address each Light fixture. Instead KNX focuses on the inputs (Switches, Sensors, Thermostats) and controls these via Actuators back at the board. A KNX system would require more Switch Cables to individually control each light fixture however the recommended approach is to control banks of fixtures and this offers a significant saving by eliminating expensive DALI ballasts.