Colour Issue

[Paul Bennett 211]

18 minutes ago, Davidmk said:

If, as you claim, 5 & 6 have the same starting address, are both in 36ch mode and neither is faulty then this should not happen.

Bit of a long shot this but take the DMX line from your desk direct to fixture 5 and unplug 7 from 6. If you have a DMX terminator plug it into the DMX out of fixture 6.

We are looking for a bad DMX connection here. If there's no change take the feed from the desk to 6 and connect 5 to the DMX output on 6. Move the terminator to 5

(If you don't have a DMX terminator then get a couple, they are fairly cheap on ebay/amazon. Put them in your toolbox and always try them first if things don't behave as expected.)

I made a mistake. The dmx number on batten 6 was different don't know what I did there... 

Now 5 and 6 are the same it is treating it as the same light. All colours are fine..  I also checked all lights and they are in 36 channel mode.. 

On a different note. Why are the fixtures set to 36 channels but I only have 3 dmx address? Does that matter? 

 

So what can be my issue? Ruled out a faulty fixture..  

[Davidmk]

1 minute ago, Paul Bennett 211 said:

Why are the fixtures set to 36 channels but I only have 3 dmx address?

The address on the fixture is the first address that fixture uses. On the desk it has been patched as 12 fixtures of 3 channels each. This is perfectly OK. If you had an FLX S desk you'd be in trouble as those desks are limited to 24 or 48 fixtures but a full FLX desk has no restriction on number of fixtures only on DMX channels.

Glad you've got to the bottom of this. Hopefully you've learned some stuff about DMX now which will help when you run into your next patching issue.

[Paul Bennett 211]

1 minute ago, Davidmk said:

The address on the fixture is the first address that fixture uses. On the desk it has been patched as 12 fixtures of 3 channels each. This is perfectly OK. If you had an FLX S desk you'd be in trouble as those desks are limited to 24 or 48 fixtures but a full FLX desk has no restriction on number of fixtures only on DMX channels.

Glad you've got to the bottom of this. Hopefully you've learned some stuff about DMX now which will help when you run into your next patching issue.

OK that makes sense.  Nice one. 

I have not fixed the issue though. I have batten 5 and 6 working as 1 light. But still have the issue if I change the address back..  So where should I look now to resolve this. 

 

Thanks for the help with this 

[Davidmk]

10 minutes ago, Paul Bennett 211 said:

But still have the issue if I change the address back

Fair point. We've established that the fixture works correctly with one starting address so it should be OK with any starting address. So, set it to the correct address (making certain that it is in 36ch mode) and make sure that the address of the first cell in this group on the desk is the same and see if it is OK now - it should be if you've got addresses and modes correct.

Edited March 3, 2022 by Davidmk
Clarification

[Paul Bennett 211]

Just put the batten 5 back to its starting number of 288 and it works!!!!

 

Thank you all so much,  Must have just been a wrong number on one of the fixtures but without knowing what to look for its had to diagnose.  Learnt quite a bit over the last couple of days about DMX so will continue watching the videos.

 

thanks again. 

[Edward Z88]

Hi @Paul Bennett 211

1 hour ago, Paul Bennett 211 said:

Just put the batten 5 back to its starting number of 288 and it works!!!!

Really pleased to hear you got to the bottom of this.

@Davidmk - thanks very much for your support 🙂

Edward

[Davidmk]

Fixing an address issue is much harder than doing it right in the first place. Everything has to be right for it to work and it's easy to skip over things because you don't believe they can be wrong - especially if it used to work and now doesn't.

@Edward Z88 suggested, you can patch these fixtures as multicellular fixtures (as long as they are in the library). This might help avoid these problems and allow the desk to use the fixtures in the best way. Stick with what you've got for now though - until you are more confident.

Try and follow a logical sequence when diagnosing. For example...

If a fixture doesn't appear to respond to the desk, even it it is doing mad random things you are not telling it to then check the DMX connections. Start with a terminator plug at the end of the line, swap out cables one at a time in case they are faulty. Worth noting that a wiring fault will often - but not always - start part way down the line and affect all the fixtures further on.

Beware of cheap fixtures aimed at the DJ market. These often have a mode where the first one generates a colour/movement/strobing pattern and controls the fixtures further down the line. Sometimes this auto mode kicks in if there is no DMX signal owing to a missing/faulty DMX cable. Nothing against such fixtures, use them myself, but it is an extra headache.

If all the wiring seems good then addresses and/or modes of the fixtures not matching what you have patched is next. If there is some sort of overlap this shows up as the fixture doing something just not what you expect. This is the situation you were in. Easy to be sure of this in hindsight but it was what @Edward Z88 and I suspected because it matched the symptoms you described. If there's no overlap then the fixture just sits there and doesn't respond. No shortcuts to this one, you have to look at the fixture,check it's mode and address and then go back to the desk and make sure they agree, if they don't then change one or the other. The desk doesn't let you overlap fixtures or choose invalid addresses so it is more likely to have the right address than the fixture so you'd probably change the fixture. If the fixture has the mode you want then you might have to change the desk and (in extreme cases) you might have to re-address a load of fixtures to do this (if the mode you want uses more channels than the mode you've got).

Finally, there's the possibility of a faulty fixture. Setting it to the same address and mode as a known good fixture will tell you if it is working properly. There is a chance that it is some setting other than address and mode but a hardware fault is probable. You can also get situations where a fixture works fine but messes up the signal to the next and subsequent fixtures on the line so it could be the immediately prior fixture causing the issue.

Finally, a fixture plugged directly into the desk with a short length of cable may fail to work when it's out in the rig. This take you back to the first set of diagnostics but bear in mind that the signal degrades over distance and number of connections so the last few fixtures don't work as they should.

The official DMX standard specifies that a terminator is required. "Pro" (i.e. expensive) fixtures often have this built in but cheaper ones may not. If you don't have one then the signal reflects back off the end of the wire and confuses things.

Edited March 3, 2022 by Davidmk
Clarification

[Paul Bennett 211]

Thank you very much.  I am going to watch all the videos and teach myself this system.  Having started a new job they have the full FLX with additional faders so want to learn it.  Am sure ill have more questions!

[Davidmk]

We all have questions from time to time.

Build your knowledge - Zero 88 training is free and well worth doing, there's the videos and, of course, there's the manual.

When you run across something you can't solve then you may be able to find a previous post on the forum for the same or a similar problem that will give you the answer. If not then the forum is the best place to ask, there's a lot of very experienced people in addition to the experts from Zero 88. You'll usually get help pretty quickly and it seems that someone from Zero 88 is keeping an eye on new posts at least during office hours and often beyond. Try not to have problems during the Edinburgh Festival though - they are pretty busy then 😁.

I've been lighting stages for about 50 years (DMX and desks as we know them now weren't invented for the first couple of those decades) but I still have questions and still learn better ways of doing stuff so don't be embarrassed to ask. The only dumb questions are the ones that aren't asked.

Enjoy your journey 🙂