KNX vs DALI

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 luminaires (either individual or across 16 groups) for measures of light level control & reporting. 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
• Ability to report on individual luminaire ballast (Dim Value, Condition, etc…)

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 (DALI2 was conceived to tackle this)
• DALI is ‘send and forgot’ meaning there is no fail safe for a lost ‘telegram’ (command)
• Often complex management systems with 2-3 intermediary systems for communication

KNX offers much of the the same functionality as DALI systems but without the need to individually address each Light fixture meaning a huge cost saving from the absence of specialist ballasts per fitting and labour to address same. KNX focuses on the inputs (Switches, Sensors, Thermostats) and controls the corresponding outputs as banks of fittings. For example each row in a Classroom setting could be a separate dimming circuit controlled by a multi channel light sensor (for Daylight Harvesting). KNX also allows for expansion beyond lighting, for example: HVAC control, Audio/Visual, Security, Remote Access and end-user visualisation.

Utilising KNX in your project as a direct replacement for DALI can offer serious savings whilst allowing a greater level of control and a more secure setup however the option to integrate DALI within a KNX system is rapidly becoming the choice of specifiers. This configuration provides the full suite of functionality and control including the ability to dynamically check ballast, lamp and battery state in luminaires for the purpose of maintenance. The control end (Presence Detection, Push Button, Server) of this configuration is entirely KNX which allows a scope well beyond lighting, i.e.: HVAC, Fire Alarm, etc…

For more info on DALI get in touch or have a look at our product offering below: