Headworx

In previous DALI myth busting episodes I covered the DALI bus polarity and DALI application controllers. This time we are going to the heart of it all: what is DALI-2 (and what it is not). This, on one hand, is the easiest one. On the other hand it is very rarely that people really know and understand what the DALI-2 logo means. There are many myths (and unfortunately many being repeated by AI assistants). Like : DALI-2 delivers device power over the DALI bus. Or control devices (see the previous post for details) are only standardized by DALI-2. This is all not accurate. As a matter of fact we could say there is no such thing as DALI-2. At least not a DALI-2 specification. Because a DALI-2 logo on a product means just one thing: the product passed DALI tests and has been certified. Practically this means the DALI organization made the best effort to ensure this product follows the specification and will interoperate nicely with other products that carry DALI-2 logo. DALI-2 does not s...

In the previous myth-busting episode on DALI I covered the polarity aspect of the DALI bus. That is: in theory it is polarity-free (it does not matter which cable goes where as far as the DALI line cables are concerned), and it practice the polarity matters (remember to connect DA+ to DA+ and DA- to DA-). This week I'd like to talk about DALI application controllers. DALI in principle has the concept of "control gear" and "control devices and application controllers". Again, the name (especially the distinction between a "gear" and a "device" is not intuitive. So lets try that: a gear is a driver. A device is a sensor or an application controller. The technical difference is much clearer. Drivers never transmit any data on their own. Only in response to a query command. Devices do the opposite - they send data on their own. So an application controller can send a dimming command to a driver. Or an occupancy sensor can send data whenever it d...

The DALI (Digital Addressable Lighting Interface) standard has had a very uphill battle in the USA. Lots of resistance, mostly quoted to it being problematic and expensive. On the other hand DALI has almost 100% market share in Europe and similarly in Asia and Middle East. DALI Alliance has been trying to change this, addressing the North American market with several campaigns, but they have not been too successful so far. And the reason is, despite DALI being a very good technology, there are many misconceptions, false myths, contradictory statements (even by the DALI people themselves). Here I'll address some key concepts that people often get wrong or are falsely propagated even by those who should know in the first place. DALI is polarity free. I have heard this so many times. Even from the founding fathers of DALI. So yes, in principle it is, but in practice it is not. DALI bus signaling works by shorting the bus. There are two wires and there is small DC (around 18V) current ...