Strand GSX controlling LED color changer problem

[CMOakley]

My new Chauvet ColorSplash DMX color changers are responding erratically to my Strand GSX light board (version 1.2a with Communique and Kalidoscope)

 

Last month I was running the ColorSplash off the DMX output of a Levitron N7516 and they worked perfectly.

 

On the Strand, I set my 3 8 channel dimmer packs (levitron DDS 8600) as DMX channel 1, 9 and 17. The ColorSplash units take 6 channels, so I set them up as 25, 31, 37, and 43. I put a terminator at the end of the chain on the last ColorSplash.

 

I have the default patch set (1:1, 2:2, etc). The dimmer packs work perfect. The colorchangers are dark when their control channels are set to 0. When any of the colorchanger's control channels are set above 0, that individual color changer shows erratic behavior. With a steady channel level from the board, the light cycles through colors and flashes. Each Color changer responds to its correct DMX channel, but not in the desired way.

 

the DMX channel for the color changer are: 1: controls mode (should be always 0) 2: Red LED intensity; 3: Green LED intensity; 4: Blue LED intensity; 5: Strobe, 6: Overall Dimmer (0>100%, 255 0%)

 

I thought I might be having some noise problems, so I connected one of the color changer directly to the board with a 1 foot cable and the terminator, nothing else in the DMX chain, set the colorchange to DMX channel 1, and got the exact same erratic results.

 

Any ideas on how to either fix my DMX chain or to program the GSX so it behaves properly.

 

Thank you

chad

[obsoperator]

Last month I was running the ColorSplash off the DMX output of a Levitron N7516 and they worked perfectly.

Were the ColorSplashes powered from the same dimmer packs when they worked perfectly? You didn't mention how the "non-dim" power is provided to the units for operation. Is it possible that the dimmer (?) they're on with a non-dim profile(?) is sending them poor power? Can you try plugging the single test unit right into the wall during the test? Just a guess.

[CMOakley]

Thanks for the reply Tim, I willing to try anything at this point. In both cases the ColorSplash are not powered from a dimmer, they are powered from a regular 110 volt outlet. The DMX-512 control signal is from different boards. They work on the Levitron, but not on the Strand GSX. One person suggested that the ColorChangers may need to be patched differently on the GSX, something other than the default patch.

[Brian]

This thread might help you.

[spotblaster]

Try patching dimmer outputs you are not using above 125 to a channel. This will have no effect on your show but will send data in all 512 slots of the DMX frame which some equipment expects. This helps sometimes with the GSX - it certainly works on the MX. I was a beta site for the GSX in the nineties, there were a couple of DMX compatibility problems I was aware of with some well known manufacturers equipment which were all sorted by those manufacturers not Strand. I have a Zero 88 Linebacker that can modify DMX parameters and has helped me on some occasions to get a GSX to control things it wouldn't do otherwise.

 

 

Spotblaster

[CMOakley]

Thanks Spotblaster and Brian.

 

I'll try the idea of patching the higher channels.

 

An update on what I've tried: I replaced the Strand with an ETC board, similiar problem, but not as bad, but still not usable. then I borrowed the NSI board that worked perfectly (in another theater) and tried it in the theater where I am having the problems. I still had some erratic performance of the ColorSplash. This makes me think the problem is not in the board. I tried running a single ColorSplash on each board with a 1 foot DMX cable and I get the same results. This makes me think its not a cabling problem.

 

One local person suggested I might have a problem with grounding. All the boards and all the dimmers and ColorSplash are plugged into grounded outlets. (but I could have a bad ground in the building, or I may have several grounds at different potentials.) It has been suggested that I lift the ground on the ColorSplash and the boards and see what happens.

 

The ColorSplashes also have a ground connection in addition to the three prong 110v supply and the DMX in and out. Should I tie all of these connections together? and include the ground from the board?

 

Is it time to call in an electrician?

 

Thanks as always for help

[peternewman]

It has been suggested that I lift the ground on the ColorSplash and the boards and see what happens.

As with sound issues, NEVER lift the protective earth of the equipment, others will hopefully be along shortly to offer advice on whether disconnecting the DMX shield or ground is likely to be beneficial.

[Tomo]

Firstly, a repeat of peter's warning - NEVER lift protective earth.

 

It sounds to me like the ColorSplashes may use a poor receiver circuit, which is unfortunate.

Alternatively, your DMX cable may be bad - just not bad enough to make the dimmers go crazy, as LEDs can respond much faster than dimmers!

 

One thing to check for immediately - does the shell of the XLR on your DMX cable connect to anything at all?

DMX cable XLR shells must NEVER be connected, as they will often introduce ground loops.

 

If this is not the case, the most likely permanent solution would be to use a DMX splitter with a 'floating' PSU (something doubly-insulated with no earth connection) to drive the ColorSplashes.

 

To check if this will solve or not, try putting a battery-powered DMX tester in the line set to 'buffer' the incoming DMX.

(Ensure it's one that doesn't connect the shield lines straight through - IIRC the Lil'DMXster keeps them isolated)

 

Full-universe 1-bit flicker-finder will help eliminate cable faults as well.

 

It sounds like the Leviton uses a 'floating' power supply, which would explain why it 'mostly' works with one of those - this would hide shell-to-shield shorts as well.

[minister_of_sound]

just a quick one, u don't need a phase reverse between the GSX and LED's do you?