Loxone DMX Dimmer PWM frequency adjust (& other Qs)

[Rob_in]

Hi all,

With recent talk here of PWM DMX dimmers, and objections to low frequency (causes flicker) I went looking for details of the stock Loxone PWM DMX dimmer frequency. Not listed on their site or shop but found an interesting discussion here:

https://www.loxforum.com/forum/hardware-zubeh%C3%B6r-sensorik/22711-rgbw-dimmer-air-flimmert

With a little help from translate, seems the Loxone dimmers are preset to 123Hz but this can be increased (someone mentioned 600Hz or even 1627Hz) via config.

I re-post here as this could be useful info for others.

I have to say, I find the concept of the Loxone DMX dimmers odd because from what I can tell from reading doco you cannot set the DMX channel on the device itself which means there's some kind of proprietary commands going on between the Loxone DMX module and their dimmers to get this set. Say you wanted to re-use a Loxone DMX dimmer with another controller (non-Loxone) in the future - how would you do this?

Robin

[Karl Peterson]

While I use the Loxone DMX dimmers, I don't know much about them. But I do know quite a bit about DMX.

I would guess that loxone is using RDM for the addressing of the DMX modules - that is the standard for such things.

https://en.wikipedia.org/wiki/RDM_(lighting)

It would also make sense as they could buy an off-the-shelf dmx decoder /w RDM capabilities as opposed to build the silicon up from scratch.

Karl P

[Deac99]

Thanks for the question.  I have been reading a ton of posts over the past week to add LED strip lighting controlled via DMX.  I've bought some cheap LED strips (RGB) and have serious concerns with both flickering and a high frequency hum presumably from the PWM driver (cheap)  The hum is totally unacceptable.  So I have basically the same question - what specifically are people using to do this?

[Rob_in]

Ahhh... thank you.

So long as it's some kind of standard that's cool. However, it would be nice to confirm. You'd have thought that sort of thing should be mentioned in the Loxone docs somewhere.

Seeing as you have the Loxone dimmers, don't suppose you could have a quick look at the dimmer in Loxone Config and confirm that PWM frequency adjustment is there. Not that I don't trust the German forum, but it would be nice to hear from a second source ;)

Cheers,

Robin

[Rob_in]

Well... would you look at that. The DMX Extension on the English shop says, "Support of DMX-512 protocol" but on the Czech shop it says, "Podpora DMX-512 a DMX-RDM protokolů (bude k dispozici s aktualizací)" which Google says means, "Support DMX-512 and DMX-RDM protocol (available with update)"

On Saturday, 17 December 2016 01:19:23 UTC+1, Karl Peterson wrote:

[seb303]

On Saturday, December 17, 2016 at 12:20:04 AM UTC, Deac99 wrote:

Thanks for the question.  I have been reading a ton of posts over the past week to add LED strip lighting controlled via DMX.  I've bought some cheap LED strips (RGB) and have serious concerns with both flickering and a high frequency hum presumably from the PWM driver (cheap)  The hum is totally unacceptable.  So I have basically the same question - what specifically are people using to do this?

eldoLED drivers are excellent: reliable & high frequency PWM.  Most of the eldoLED constant voltage drivers require an external power supply (this can be shared between multiple drivers).  I use Meanwell brand PSUs, which seem pretty good.  Reliable so far, and completely silent.

[Deac99]

Thanks Seb - that gives me a good starting place. 

[Joakim Arfvidsson]

I don't think you can change the frequency of the Loxone DMX dimmer. And I agree, it's too low to use. I would not consider it.

Here's the best I've found for constant-voltage PWM dimming: http://www.shop.dmx4all.de/en/dmx4all-products/led-dimmer/dmx-led-constant-voltage-dimmer/DMX-LED-Dimmer-X9HR.html

It does 244Hz, 2kHz, or 4 kHz. 9 channels of 10 A each. It's really a great value for any constant-voltage app IF you need 12-24 V. And they sell a DIN housing to mount it next to your Loxone system.

Note that Loxone's spots don't like 2 kHz. Their internal circuitry is not fast enough and their dimming curve becomes wrong (too bright, opposite of logarithmic curve). 244 Hz I found pretty tolerable, and with the HR mode of that driver you get super-sweet accuracy around the lower range. True 0 % dimming (if you consider PWM dimming).

I was looking into constant-current dimming as the final solution to PWM headaches. Eldoled's CC drivers are some of the best in all, but note that they do use PWM in their current control. It's high frequency - higher than 244 Hz for sure - and it only uses this at some dim levels.

[Rob_in]

I do like the look of this, although the manual states, "This assembly (board) is controlled by a microprocessor and uses high frequency (8MHz). To get the characteristics of the assembly in relation to the CE-conformity, an installation in a compact metal casing is necessary."

So in order to be CE approved (and this is mandatory for our project) it must be fitted in a metal case, but then they will only sell you a plastic enclosure. Doh!

[tzajaczk]

I've just called LOXONE french technical support : they said that "available with update" is a "misstake"... On german site this notification does not exists.

For now, I'm unable to connect KAPEGO DMX 512 *4 channel dirvers...
The problem is to find out some led-drivers "compatible" with LOXONE as they seams to not support a whole DMX-512 protocol.
We've tested a coupple of "professionnal" dmx projectors and still the same punishment : no signal detected ...

Tested with the old PWM DMX Loxone's dimmer : everything works perfectly...
Am I right saying that this is LOXONE'S DMX ?

Any advice for LED Constant Voltage DMX dirvers (12-24V DC) which works with LOXONE DMX extension ?

[Duncan]

i have tested loads of no-name cheap chinese dmx dimmers and never had any compatability issues at all

ive also used a few branded dmx dimmers both mains voltage and low voltage and again have had no problems

the only limit that i know of is that loxone only supports device upto 128, not 512, so as long as you address your devices in that range then they should work fine
also the loxone dmx detect function doesnt work with most 3rd party drivers (might work with rdm capable?) so you have to manually configure each devices device ID and add them manually into your config.

the better drivers have been the brand LTECH, which have good bottom end dimming, are cheap and are available in CV and CC and have models with inbuilt power suppies as well as the usual DC ones
http://www.ltechonline.com/html/en/products/

[Rob_in]

I finally gave in and called Loxone about this (bit of a wait on the phone) after trying to get this information out of them via email/chat (both of those channels seem broken - I was told they are changing systems).

Anyhow, the guy on the phone from Loxone told me the PWM frequency of their dimmers was optimised to work with their LED products and, no, the frequency wasn't adjustable. While this is straight from the horses mouth, you never know if that could be some kind of unsupported feature or something. Either that, or the German forum is just plain wrong. But there you go.

BTW, I was also told that yes, a Tree Dimmer is in the works but release date is unknown.

HTH,

Robin

[tzajaczk]

Dear Duncan ... :) Thanks a lot for your advice. I've just received LTECH dimmer driver and ... it works perfectly.
Thanks for your advice.

I'v tested two of their products : LED CONTROLLER DMX 12x5A (ref. 22711) and LED CONTROLLER STANDALONE + DMX (ref. 22732)
Both of them receives LOXONE DMX signal.

I wonder why KAPEGO or others are unable to analyse this signal...

Anyway, LOXONE's offices are closed upto 9 of january ... long, long hollidays ...  the voicemail, only in german, gives this information.

Kind reagrds