MADRIX Forum

Hi Guys,

We have completed a couple of digital tape installs and are having DMX corruption issues. We have experience of putting an electrical isolation device in line to solve but I'm having issues with these installations and looking to see if anyone else has encountered this.

Firstly can someone tell me what the rule is for the length of cable between the Nebula output and the start if the first tape? Also why might it have to be so short? I just want to understand how it works to be honest and the need for the restriction.

We have a tape install using two Nebulas, essentially a circle split in two halves. One side showed signs of DMX corruption so we put a DMX splitter DD-2 which has electrical isolation in line and it was solved. However, when we power the system up, ALL the tape on that side illuminates white then the white subsides as the corruption displays badly then that subsides and everything comes good. It's super weird. We also notice a link between the brightness of the effect and the level of corruption. The brighter the effect, the less corruption there is.

So either way our installation has been working perfect for 10days then the other side started to get crazy corruption. We attended yesterday to put another DD-2 on the other side but as soon as we place it inline, the whole side sticks on full white with no control from Madrix. I have tried several DD-2's but they all do the same. I know the DD-2 just passes the DMX but the tape is not liking it. As soon as I remove the DD-2 and just come straight back out of the output of the Nebula, the effects are restored but with the potential to get crazy corrupted at any moment. So I am stuck in a situation where we have DMX corruption, and when we try to introduce the correct product to solve it, it makes things worse.

Any help would be appreciated.

Regards


Scott

Hi!
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Thank you for your post!
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Here is an excerpt from the NEBULA technical manual:
'SPI protocols are sensitive to interference. Hence, the max. recommended wire length between NEBULA and LEDs as well as between LEDs is 0.5 m.'
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The longer the wire, the more interferences it will take up and the more power would be need to transfer the signal.
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Now regarding your case, we cannot recommend to use DMX boosters, since SPI signals are simply no DMX signal. We would not expect that to work at all and to solve any issues you may have.
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Since you are raising these points in your post, I would strongly recommend to check your wiring again. If you need more assistance, please send an e-mail to info[at]madrix.com and please include a scheme how you have connected your LEDs, including wire lengths, LED types, etc.
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Thank you very much!