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    Jay
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SeaChanger "Twitching"

I have a handful of seachangers in a rig controlled by an Eos as main, Ion as backup, Net3 DMX Gateways.  It seems that the Seachangers are randomly having a flag go in quickly then back out.  Sometimes it happens a lot, sometimes it happens with long gaps between.  I thought maybe there was something up with the gateways (which seem to work fine on all other aspects with VL1000s and Revolutions and scrollers etc) so I slowed down the rate to slow.  Still no change.  I plugged the 2nd Universe into the back of the ion to see if that magically fixed it and in the little bit of time I was able to watch I no longer saw the twitching.  Anyone have any ideas.  Thanks in advance.

 

Jay

  • 0

    I don't know if this will help you, but try turning off the RDM function on the Net3 gateway port the SeaChangers are plugged into.  You will have to do this with Gateway Configuration Editor (GCE) which should be on your console.

    I've had a few jobs recently where a number of anomalous flashing/twitching fixtures have been resolved by turning off the RDM function.  I've been told by ETC that the gateway itself is sending an RDM discovery heartbeat most of the time to continue discovering fixtures out on the DMX link.  If your fixtures are not RDM capable, they may react oddly to the discovery function, and it might be that twitch you see in the color flags.  I can say that CK iColorAccent fixtures flash very periodically when RDM was enabled, and I've had a customer indicate to me that Martin Atomic 3000 strobes have done similar things until RDM was turned off.

    Can't hurt to try that.

     

    Good luck.

     

  • 0 in reply to Holztech

    Further to Dennis' comments - if you do find a fixture that responds badly on a DMX link with RDM, it is worth reporting it to the manufacturer of the device. RDM was designed to not cause problems with legacy equipment that complies to the DMX standard.

    If you also have RDM devices on the same line and want to continue to use these functions, you may want to look at a product to place inline to "remove RDM", such as this Fleenor device: http://www.dfd.com/strip.html.

    Luke

  • 0 in reply to luke.delwiche

    Where are the SeaChangers in the DMX run?  Also is that DMX run terminated at the end?  RDM is very finicky and always needs to be terminated.

    If plugging into the back of your Ion fixed it, then I would most definitely say that the SeaChangers are responding to a RDM message.  The Ion currently doesn't do RDM on the local DMX ports so this would explain why the behavior stopped when you plugged in to the console.

    The first generation of RDM that was implemented in the SeaChangers didn't necessarily meet RDM spec and the twitching was one of the issues that I have seen.  The best option is to move them to a separate DMX run and disable RDM on that port; as stated above.

  • 0 in reply to speterson

    I can confirm that SeaChangers purchased in the 2008 timeframe do have timing problems with RDM, which shows up as a color wheel twitch. For a permanent fix, you might contact Ocean Optics and see if they will upgrade the software on the SeaChangers.  This involves reprogramming the microcontroller, so it's a trip back to the factory, not a chip swap or upload.

    -Todd

     

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