How can DMX and DALI luminaires be combined in a single system?

This question has been answered by Bas Hoksbergen, architectural market manager, Pharos Architectural Controls

There are many valid reasons why you might end up with both DMX and DALI fixtures on a project. For example, the fixture you need may only be available in one of the two protocols. So what are your options, and what are the advantages and disadvantages of each approach?

Protocol converters

The benefit of using a converter is that after initial setup, you only need to maintain a single control system. The drawback is that DALI and DMX are very different protocols and cannot achieve the same system functionality or results (see What are the differences between DMX and DALI – and does it matter?). There is a wide selection of DMX to DALI and DALI to DMX converters in the market, all operating with a slightly different approach.

Some considerations when selecting a DMX to DALI converter:

  • What is outputted on the DALI bus? Can you recall scenes, or only adjust intensities? Can you control individual fixtures, or does it broadcast only?
  • Refresh rates. Because DALI has a slower protocol, it will take seconds to send individual information to 64 DALI luminaires. When translating only a single DMX value (such as broadcast this to all connected fixtures) the speed can reach up to half that of the DMX.
  • Repeating messages. Many converters will continuously send DALI messages on the bus, even if the DMX values stay the same. If you have sensors, button stations or other items on the DALI bus, this might not work, as the bus is flooded with DALI messages.

Some considerations when selecting a DALI to DMX converter:

  • How are the ‘DALI ballasts’ mapped to DMX? If I use RGB DMX fixtures, does this require three virtual DALI ballasts? Can I use all 512 addresses on the DMX bus, or must I start at  one?
  • How does it handle DALI fade times on the DMX side?
  • Can I recall dynamic effects?

Two independent control systems

You could simply install two separate systems, one for DMX and one for DALI. Of course, the drawback is that the systems will need to be programmed and operated independently, so for example you cannot ‘turn everything on/off’ or ‘change the setting’ with a single push of a button.

Simple linking

Many controllers offer the ability to be triggered via contact closures. You could add some relay outputs to system A, and use these as inputs to system B. This will involve a lot of hardware and installation effort with limited results. Even though this happens regularly, this should really be considered a substandard solution.

Controller integration

Integrating two control systems sounds complicated, but it does not need to be. If your controller can be triggered by the other protocol, you can simply use that protocol to communicate between the two systems, while retaining the advantages of each protocol.

Suppose you have a DALI system where a group will be replaced by DMX luminaires that need to show some dynamic scenes. If your DMX controller can be triggered by DALI, you can use the DALI messages to recall scenes and set intensities on your DMX fixtures.

Similarly, if you have a DALI control system that can be triggered by DMX, you could use a specific DMX channel for DALI scene recall, another DMX channel for intensity broadcast, and so on. The control system needs to be intelligent enough to only send DALI messages in case of relevant changes in DMX values.

System integration can become very advanced and use other communication methods than DMX or DALI, but if you just want to combine DMX and DALI, it can be very simple. Pharos offers a control lighting solution that can be used to augment a DALI installation with DMX or vice versa.

A controller system that supports both protocols

This is the most flexible and powerful solution, and in many respects the simplest. There are control systems that simply support both DMX and DALI, achieving the best of both worlds. These need not be advanced building management systems, they can also be simple standalone DIN-rail controllers. The Pharos TPC and EXT accessory is an example of a simple system that will control and output both DMX as well as DALI.

Of course, such a controller cannot overcome the fundamental limitations of each protocol, such as making DALI fixtures do the same dynamic effects as DMX, but will help you in programming the environment to be set up to your dynamic and static lighting scenes as required.

Besides DMX and DALI, there are other lighting control protocols such as Bluetooth, Zigbee, and DMX over Ethernet. Choosing a control system that can natively speak to other specific protocols you have in your project is a good recipe to ensure you receive a great programming experience.

Pharos controllers can output DMX512, DALI, and DMX over Ethernet protocols like Art-Net, KiNet, and sACN. Furthermore, Pharos IO modules allow you to directly control Xicato, Hue, Philips Dynalite (and more to come) luminaires and load controllers, that can be fully integrated with your DMX and DALI programming.

For more information on Pharos Controls, please visit pharoscontrols.com

 

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