# DMX can bite me



## punktech (Oct 30, 2007)

i swear the recommendations and it in it self are so annoying, i got an error message on a CXI color mixer last night that the manual didn't even list...grr. anyone have an "endearing" DMX stories that i can commiserate with/laugh at. i need stories right now...


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## icewolf08 (Oct 30, 2007)

Sure, had a couple from the show I am working on. First couple issues I had was actually human error. One of my long time crew members decided that the Ellipscans (mirror head similar to i-cue) didn't actually need to get a data cable. Apparently you can now just give power and set the address... Huh, didn't get that memo. So that led to an un-needed break in tech while I had to go sort out the issue.

Now I have one Ellipscan who just doesn't want to play along. It seems to work OK right after power up, but then it kinda drifts off. It will move when we tell it to, but not to the right place, and if you reset the positions, it is wrong again after you reset the unit. Go figure. And this is on terminated DMX lines...

I also have one elipscan that just doesn't like being set to some addresses. It just won't work if you set it to a few particular addresses. This is very much a PITA, because every time it gets used, I seem to find an address it doesn't like. Maybe it just doesn't like the first address I give it for a particular show, who knows.


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## derekleffew (Oct 30, 2007)

Umm, exactly how is an error message on (I assume) the CXI power supply the fault of DMX-512A?

The only time I've been frustrated with DMX is when a fixture in a chain begins to function erratically, and the problem turns out to be a bad cable several units farther down the line (with or without proper termination). Plugging a Fleener DMXTSTR into every output of both fixtures and cables eventually determined the problem, but not so easy to do once the truss is flown 35' above the arena floor!

As to your Wybron problem, there's an article titled "Info Trace Enters _Spamalot_" in the October 2007 issue of _Lighting&Sound America_, you might want to peruse. In 1998 I used what I believe to be the forerunner (no pun intended) of Info Trace called "Watchdog," and found it invaluable in keeping track of scrollers located hundreds of feet away and out of sight of the control area.


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## len (Oct 30, 2007)

Are those HES color pro CXi? I had an issue with the FX version once. Tried everything. Finally ended up deleting all the cues I had for them (driving a fiber optic curtain) and starting over. 2 hours of troubleshooting. To this day I don't know why they wouldn't respond to the old cues. But the new cue list (with the same addresses) worked fine. And I never had an issue with them before or since.


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## Jervas (Oct 30, 2007)

punktech said:


> anyone have an "endearing" DMX stories that i can commiserate with/laugh at. i need stories right now...


Endearing? not at the time but funny now -Some years ago I was producing a large scale outdoor "picnic style" Shakespeare show in the grounds of a large manor house here.
As you may have discovered with these sorts of venues, they are reluctant to have you over long seasons and usually book other more profitable 'in their eyes' stuff in around you that you have to deal with.
Anyway, so i'm at home and I get a phone call at 7.30am on one of the Sunday's we have a show on from the guy we hired our gear from -par cans long DMX runs, racks, trees etc. He says "I think you need to get up here - we've got a problem"
So I take off asap and arrive at the venue about 20 mins later to find the hire guy sitting between two of the twelve Norfolk Pine trees we had slung our 100 metre (338 feet) DMX run through - At about 4 meters (13 feet) in the air.
He was holding one end and the other was streched out to buggery and flopping around against the tree trunk.
Huh? I hear you ask - seems the function load out on the Saturday night saw some idiot try to turn a truck around between the two trees in question - strech the DMX to the point of no retun and finally snap it!
And here's the really scarey bit - the driver wasn't going to say ANYTHING! He only did in the end because he is employed sometimes by the hire guy!! (small city is ours)
So - we made do with a lengh of suitably rewired audio lead until we could get a new length of DMX on the following Monday.
Oh, and testing showed that the streched lead was completely screwed!. Cutting off 1 metre (3 foot) lenghts and testing yeilded 100 or so short lenghts of CLOTHESLINE!!! (no signal ever again)
Like I said - funny story now - but then with 500+ booked in for the Sunday Show - Svinkter puckering material I can tell ya!


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## derekleffew (Oct 30, 2007)

Okay, I'm reminded of another DMX story. At a place I used to work the lighting dept. would regularly "borrow" 3pin XLR cable from the sound dept. for use as moving light data cable. <I know, I know.> The sound dept. head one time facetiously told us "Just keep the cables you stole. Once DMX runs though them I can't use them as mic cable anymore anyway." Upon over-hearing this, a newbie sound guy asked, in all seriousness, "What happens, does the DMX melt the connectors or something?"

This was the same Audio Dept. Head who always insisted on a totally separate power source for audio, yet once in a emergency when we plugged his audio distro into the output CAMs of a Sensor rack there was actually LESS 60Hz buzz in his audio system. He never lived that one down.

I would sometimes run DMX down his mic snake and he swore he could "hear" the DMX. Other times when he didn't know it was there he never said a word.


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## punktech (Oct 30, 2007)

well, my error message last night was one of those "what the...oh crap, what does that mean, why is it saying *alert*? hmm, maybe if i just unplug the DMX, and now put it back...YES!" situations. that wasn't the only fun though, just the one that stuck out best in my mind. i personally love our 100 foot, unterminated line, that comes in second in DMX-sucks-land (i really want RDM/ACN). i have to go into tomorrow and work on some more crap that is wonkying on us, so i may get more stories for my personal collection.

my all time favorite operator error happened last year, so my friend Zach, who was a senior at the time was handling the DMX, and we had 2 floor mounted S4 Revs upstage on either side. well he had them partially working at one point, and was doing some board jockeying to get them working fully. while he was in the booth the Revs had to be moved for some reason or another, and someone un plugged the power on it...well Zach goes to check it out after he finished messing about with the server, and he freaks becasue now it won't turn on... some one comes up to him and says, "well buddy, it might help to have the power plugged in.". he found the freshie that failed to re-plug the power and gave him a thorough verbal beating on break.


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## derekleffew (Oct 30, 2007)

Again, I'll ask, what does this have to do with DMX? Almost all the above examples relate to the equipment devices rather the data transmission protocol. If you think RDM/ACN is/are going to solve any of these problems, I fear you're mistaken. I for one would rather set a DMX address on a device than an IP address, and I can't imagine home running each moving light back to a hub/switch as opposed to daisy chaining. DMX-512A will be with us for at least the next 10-15 years (after all, another poster is planning on using a 45 year-old Ariel Davis board) so it's possible some of us will still be using DMX in 2031. 

Possibly I'm over-reacting, and the thread is just mis-named, but someone has to defend a technology that revolutionized our industry, and allowed computer control and moving lights available to just about everyone. Perhaps if you'd have experienced LMI's "magic boxes," demux cards, and Cinch-Jones connectors, you'd have a deeper appreciation.

Oh, and how was your 24-hour marathon call? Did you get everything done you needed to?


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## Logos (Oct 30, 2007)

I agree with Derek. The joy of being able to daisy chain a single data cable to run everything is unbelieveable. Every so-called DMX error I have come across has either been operator error (mis set addressess etc) or a cable fault. I have very few problems even if I run mic cable if I terminate properly. Sometimes a device misbehaves but that is not usually a DMX problem it's usually the device. Compared to what we used to have. Heaven.


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## Kelite (Oct 31, 2007)

<I for one would rather set a DMX address on a device than an IP address, and I can't imagine home running each moving light back to a hub/switch as opposed to daisy chaining. DMX-512A will be with us for at least the next 10-15 years (after all, another poster is planning on using a 45 year-old Ariel Davis board) so it's possible some of us will still be using DMX in 2031. >

My bet is that many hundred other lighting techs are in silent agreement with this line of thought. While not perfect, DMX does exactly what it's intended to do- as long as it's fed and watered properly.


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## gafftaper (Oct 31, 2007)

Kelite said:


> <I for one would rather set a DMX address on a device than an IP address, and I can't imagine home running each moving light back to a hub/switch as opposed to daisy chaining. DMX-512A will be with us for at least the next 10-15 years (after all, another poster is planning on using a 45 year-old Ariel Davis board) so it's possible some of us will still be using DMX in 2031. >
> My bet is that many hundred other lighting techs are in silent agreement with this line of thought. While not perfect, DMX does exactly what it's intended to do- as long as it's fed and watered properly.



Once again we are going to see a split in the industry. The new places and shows with budgets will go down the ACN/RDM path. While most of the community theater, educational theater, and church world will keep using their Altman 360's, Old Strands that they can't get parts for, and DMX if they managed to afford the upgrade to that. If they didn't have the money to upgrade to DMX they won't be jumping on the ACN bandwagon right away either. There's a lot of Cinch Jones still out there my friends.


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## Hughesie (Oct 31, 2007)

dmx is out dated but serves it purpose, once configured


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## icewolf08 (Oct 31, 2007)

Hughesie89 said:


> dmx is out dated but serves it purpose, once configured


curious as to why you think DMX is outdated. Sure, I like New technology, but when you look at it like Derek has, it means a lot more work for us to get the same job done. It will always take less time to set an address and daisy chain than to home run everything. Not to mention that home runs will require more and longer cables. DMX may not be perfect, but it works, and it gets the job done. Plus, with the shear number of DMX compliant gear that is in use worldwide, it is going to take a very long time for people to switch. No one is going to buy an ACN only controller when they have a huge inventory of DMX gear.

I wonder if we will even see a full switch to ACN any time soon. Maybe to talk to dimmers and nodes, but I think that we are going to see DMX nodes and drops around for a very long time. Our industry is always years behind the rest of the market in technology, mostly because no one has the money to upgrade as fast as the technology changes. I for one, am not holding my breath.


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## Charc (Oct 31, 2007)

Kelite said:


> <I for one would rather set a DMX address on a device than an IP address, and I can't imagine home running each moving light back to a hub/switch as opposed to daisy chaining. DMX-512A will be with us for at least the next 10-15 years (after all, another poster is planning on using a 45 year-old Ariel Davis board) so it's possible some of us will still be using DMX in 2031. >
> My bet is that many hundred other lighting techs are in silent agreement with this line of thought. While not perfect, DMX does exactly what it's intended to do- as long as it's fed and watered properly.



Eboy87!

I found your jar of peanut butter. Kelite took it to feed the DMX in the Apollo R&D labs.


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## punktech (Nov 1, 2007)

i would like to point out that i said i want RDM as well. that's wireless, no more cable is a nice idea, neater backstage areas are really a great concept. sure there will still be interference, different causes but still it won't be perfect.


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## soundlight (Nov 1, 2007)

RDM is not wireless, RDM stands for Remote Device Management. If your board and your fixtures are RDM capable, and you're using real 5-pin DMX cable, then you can remotely address your fixtures from the console or a seperate RDM programmer. Also, RDM if a DMX "add-on", and ACN is a completely new protocol. You really can't use both unless you run two protocols and have money pouring out your ears.


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## Eboy87 (Nov 1, 2007)

charcoaldabs said:


> Eboy87!
> I found your jar of peanut butter. Kelite took it to feed the DMX in the Apollo R&D labs.



That's where it went!!  Must not have been too hungry, the jar magically reappeared last night when I got home from the Halloween party.


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## jaredwooden921 (Dec 14, 2007)

Ha,

Reminds me of when our coller scrollers decided to 'Calibrate' in the middle of act II of our musical.

Good Times.


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## icewolf08 (Dec 14, 2007)

jaredwooden921 said:


> Ha,
> Reminds me of when our coller scrollers decided to 'Calibrate' in the middle of act II of our musical.
> Good Times.


I know this is a relatively old thread, but, once again, your scroller calibration issue most likely had nothing to do with DMX. Chances are you had too many scrollers or too much cable on one power supply and when you tried to change colors the voltage dropped low enough for the scrollers to think they had been powered off. When the voltage came back up they powered back on.


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## len (Dec 14, 2007)

derekleffew said:


> I would sometimes run DMX down his mic snake and he swore he could "hear" the DMX. Other times when he didn't know it was there he never said a word.



The other fun thing to do to squeakies is to tell them you already did run it, when you didn't. Then when something goes wrong, they complain it's the dmx. Let them ***** for several minutes before you tell them you never ran it thru their snake.


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## derekleffew (Dec 14, 2007)

len said:


> The other fun thing to do to squeakies is to tell them you already did run it, when you didn't. Then when something goes wrong, they complain it's the dmx. Let them ***** for several minutes before you tell them you never ran it thru their snake.


That's so evil! I love it!


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## avkid (Dec 14, 2007)

len said:


> The other fun thing to do to squeakies is to tell them you already did run it, when you didn't. Then when something goes wrong, they complain it's the dmx. Let them ***** for several minutes before you tell them you never ran it thru their snake.


Most of us aren't that dumb.


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## punktech (Feb 3, 2008)

avkid said:


> Most of us aren't that dumb.



oh but some of you are, and that is why it's fun to screw with sound guys...


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