Control/Dimming Chauvet Colorstrip problems

[Dennyd]

Hi group, New to Control Booth but hope you can help.

I have a lighting environment that has 8 Chauvet Colorstrip LED bars. These bars are at the very beginning of the DMX run and have been assigned DMX address 1 thru 32 (fixtures are 4 channel). I also have a lightronics industrial 24 channel dimmer that controls about 10 source four elips and all the house lights, 1, 4 channel dimmer pac and 1, 6 channel dimmer pac, both controlling PARCAN lights. 5 ADJ color changers and 2 ADJ 575 moving heads. The end of run is the 24 channel dimmer and is terminated. My problem is with the Chauvet colorstrips. I can use the function mode (preset colormixes of red, green, purple, red, blue, yellow and white with no problem, but when I got to RBB (colormix mode) all eight of the colorstrips begin to sproadically blink on and off randomly with no identifiable pattern. I am using ShowCad Artist controller software and the template for the colorstrips has been checked and double checked by Chauvet and I am advise it is correct...channel 1 is set between 210 and 219. I am hopeful someone out there may have an idea how to correct the problem. Thanks.

 

[BillESC]

Try slowing down the refresh rate of your controller.

 

[JohnA]

Hello Dennyd, welcome to the CB Forums. I have commented about these issues in prior posts. It is not merely a matter of slowing down the refresh rate. Look for posts in the thread Check me here guys...(Jands Vista/Chauvet ColorStrip) August 13, 2009. The best response was from SHARYNF. Here is what she found:

So we just were able to get a technical description of exactly what the problem is with the color strips from Milton Davis of Doug Fleenor Design

The issue is that the Chauvet fixture can not cope with consecutive DMX bytes with no time between the bytes. The DMX specification says that the time between consecutive bytes can be 0 seconds to as much as 1 full second. A large percentage of control consoles produce no time between bytes. The Chauvet fixture doesn't have enough processing "horsepower" to take in the byte and prepare for the next one if they are sent back-to-back with no time between them. The result is flickering or shifting of levels. In order to operate correctly, we add about 40 microseconds (0.000040 seconds) of dead time (also called "marking" time) between DMX bytes. This allows the fixture enough time to receive the data byte and get ready for the next one. Some consoles such as the newer ones from ETC take care of this issue by adding the appropriate dead time when their DMX outputs are set to the "slow" mode. The resulting output update rate for their consoles or our interface is about 25 Hz. Our interface doesn't care what the incoming update rate is. We take in the data, put it in a table and transmit it with timing parameters that the Chauvet fixture can cope with. The incoming data rate and the outgoing packets are completely disconnected in terms of timing; only the DMX data is passed along.

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I had gotten several retrofit kits that Chauvet made to correct the issue. The kits worked--BUT the bad news is they no longer make them. I tried to get on for a color strip mini about 2 months ago--but they said none were available. I have not tried the Fleenor kit nor the "DMX slowdowner". I don't have an ETC console; according to their staff they have a "fix" for their consoles. For the rest of us--it looks like one of the aftermarket products $$ will be needed. --JohnA

 

[AhClem]

I don't know if it will help, but the DMX specification does not require that the controller send all 512 addresses if not required. (i.e. if you only use the first 100 DMX channels, the controller may only send 128 DMX values then start over) I'm not familiar with the ShowCad Artist but if you (re-)assign one of your fixtures to an address up near the upper 512 limit, it may help slow the refresh rate to the point the Colorstrips can be fooled into functioning.
If they really require a specific millisecond interval in the DMX 'mark after break' packet, this may not work, but at the same time it may be worth a shot.