DMX issue

Do you have a proper terminator at the end? Make sure the resistor in your teminator is 120 ohm.

This doesn't sound like a cabel issue b/c you have properly functioning units at the end of the chain.

If it's not the terminator, then the best way I've found to troubleshoot probelms of this kind is to selectively remove devices from the link from the start to the end.

So go to your first unit and unlug the DMX lines and plug them in together. If no change, move on to the next.

This won't sort out a bad cable, but it should lead you to any device that may be corrupting the signal along the way.

Hope this helps. :)

Hi, just for notice,

I had the same problem a few weeks ago with 575 spot and 2 color power.
I did the same thing that marty explained. And wonder...... It was a bad cable after the second unit.

Hope this helps and good luck

Roman

[quote=Roman]And wonder...... It was a bad cable after the second unit.

Ahhh the paranormal mysteries of DMX.....

I also make it a general rule not to mix different fixture types on the same line if I can (budget permitting).

Opto-splitting is often the fix to many DMX oddities. It might mean a few more data home-runs, but I've found it to be worthwhile.

[quote=Marty Postma]Ahhh the paranormal mysteries of DMX.....

I also make it a general rule not to mix different fixture types on the same line if I can (budget permitting).

Opto-splitting is often the fix to many DMX oddities. It might mean a few more data home-runs, but I've found it to be worthwhile.

Amen brother, preach on!:notworthy:
Theres something about Cybers and Color powers, they just dont seem to play well with others.:poke: Then theres always 'OPL' (other peoples lighting) cough.. Made wherever by who ever with what ever as parts.

Start the search on the end and work your way back to control. It wont take long.

What console are you on? Are you sure it is a data problem?
Is it possible the fixtures have been PARKED, or UNPATCHED from the show?
Do the fixtures appear to have power?

Mitch

I am running two Whole Hog 3's for these instruments. A console for live shows, and then we switch to a rack mounted unit for the daily atmosphere lighting. They are not parked and they are still there in the patch.

All of the instruments are working and behaving fine when I go to teh instrument and use the manual controls, it is just not listening to either hog.

I havent yet been able to get up to the instruments to try and isolate any issues yet because of continued events happening directly under the instruments every day. (ah the life of a casino...)

I sure wish I had the budget to make individual runs for each instrument type. That would sure ease my mind for most of this room.

Back to pecking away..

-Scratch :trink26:

Ok, my situation confounds me even more...

So the colormerger units on the end of the line work fine. I started a the end and began taking instruments out of the line, just connecting the lines to bypass them... and the colormerger stopped working.

How is this happening? I tried multiple units with the same results. When they were out of the line, the Cm units would no longer work.

Dmx is a blessing and a curse.

Right now, I am leaning to the curse part.

-Scratch

Those symptoms sound more like bad cable. Bad as in the wrong type of cable. One that is not spec'd for 485 communications. Like microphone cable. I say this because you said you inherited this venue. Make s me think the cabling is existing runs in the house.

Possible things to do...

First,
Verify the cables from source to 1st fixture, 1st to 2nd fixture... and so on.
Their manufacturer and specs should be printed on them.
Here's a link to more info.

www.usitt.org/standards/DMX512_FAQ.html

Second,
The other problem may be a failing connection at one ond of a cable.

Third,
Or as Marty said, a fixture corrupting the DMX
Sounds like you started doing this.
You can go back again and start at the beginning adding fixtures to see when they go bad. Rememeber that as you pull the cable to the next fixture you'll need to terminate the output.

Also, can you get your hands on a good DMX tester?

Hope you figure it out. When you do tell us.

Cat

One bad solder joint can ruin your whole day.:aargh4: :aargh4: :aargh4: :aargh4:

Scratch,

Any updates?

Cat

What about a possible short circut at some point....... could have shorted some fixtures and left others without hurting them.

Kris.

Hey Chris,
I am assuming that is not the problem, as if there was a short, there is no way the last fixture would work..

My guess is a bad cable or fixture somewhere corrupting the data.
Joshua Wood

I was thinking more a temp short..........
i.e one thats not there anymore. could have damaged some DMX cards.

have you tried connecting each fixtures DMX straight from the desk.

Do the lights in question ever soom to work

Good point! Seen it happen.
Borrow a DMX'ter and check your lines. Make sure you are getting 512 length along with all the other specs.

Sorry, I fixed it right before Mardi gras and have just been forgetting to update.

or I should say I made it work....

We bypassed the hardwire in the walls and just jumped straight from our DP down to the lights and they work fine now.

We are going to go back and check the lines slowly when things slow down around here.