Control/Dimming - Pearl and ETC rack communication problems

[willbb123]

I am set up for the show tonight and I'm having a problem I can't come up with an answer for.
I have a Avo Pearl Console, connected to an ETC Sensor (not plus) 24 dimmer rack on line 1, and some Mac 2ks on line 2. This morning I programmed all my lights with the console on stage (ran two 25' 5pin homeruns). After programming I moved my console to FOH. Data running through a 300' dmx snake. I know I tested the macs, and want to say I tested conventionals, but I am not sure.
Later in the day I connected my hazer (DF50) into the "A Through" on the ETC rack, and walk to FOH to test it out. No response from hazer, or any conventionals. ETC rack says "No data line A". After trouble shooting my cable, and data snake, I plug the line (at FOH) into a Leprecon 612 and the ETC rack works fine. Thinking its a bad output on my Pearl I re-softpatch to lines 3 and 4; nothing. I then tried sending it out of my know working line (Mac line 2). I even switched out the brain on the ETC rack.
Finally I activate the input B on the ETC rack, plug in DMX and the rack immediately comes alive.

What happened to make the ETC rack not respond to the Pearl on line A, but still respond to the Leprecon?







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[derekleffew]

I don't know, but once did experience a similar situation whereby the output of a Pearl would not pass through an ETC I5M opto-splitter, but worked fine with a different brand. Of course I blamed this on the Pearl and vowed never to touch one again, and I haven't.

Did you reboot both the Pearl and the CEM? Let us know if the problem doesn't correct itself on the A input. A DMXTSTR may or may not have helped in your troubleshooting, but is something everyone should keep in his bag o' tricks.

[TimMiller]

Were you using the 5pin Y cable? I have had issues with some equipment not liking data on pins 4 and 5. I always use the y cables even when I am only using a single universe. FYI for non avo users the pearls have 2 dmx outputs but 4 universes, the second universe is on pins 4 and 5. Dmx output 1 are universes 1 & 3, output 2 are universes 2 & 4. There is a y splitter that you use to separate the universes.

[techieman33]

Were you using the 5pin Y cable? I have had issues with some equipment not liking data on pins 4 and 5. I always use the y cables even when I am only using a single universe. FYI for non avo users the pearls have 2 dmx outputs but 4 universes, the second universe is on pins 4 and 5. Dmx output 1 are universes 1 & 3, output 2 are universes 2 & 4. There is a y splitter that you use to separate the universes.

Must be an older avo thing. Our 2010 expert has a port for each universe.

[DavidNorth]

Later in the day I connected my hazer (DF50) into the "A Through" on the ETC rack, and walk to FOH to test it out. No response from hazer, or any conventionals. ETC rack says "No data line A". After trouble shooting my cable, and data snake, I plug the line (at FOH) into a Leprecon 612 and the ETC rack works fine. Thinking its a bad output on my Pearl I re-softpatch to lines 3 and 4; nothing. I then tried sending it out of my know working line (Mac line 2). I even switched out the brain on the ETC rack.
Finally I activate the input B on the ETC rack, plug in DMX and the rack immediately comes alive.

What happened to make the ETC rack not respond to the Pearl on line A, but still respond to the Leprecon?

I would guess that it is one of several things. Could be a wounded DMX receiver chip for port A [75176], or damaged or incorrect wiring for port A in the rack. DMX can work correctly when Data- or Data+ is missing, depending on what receiver chip is being used and whether or not the console has grounded or floating DMX common. Then when you add other DMX gear on the same data line, how that gear references ground on DMX common can determine whether the DMX signal works or dies.

Only a guess at this point.

The easiest next step is to swap the two DMX chips in the CEM [75176] if you are comfortable doing this without bending pins. If the problem now shows up on port B, then you have a wounded DMX chip. Yes, it is possible to have a partially function DMX receiver chip.

If that doesn't get it, we should chat before any other changes are made as internal wiring is rarely a problem and other information may lead us to another solution.

David

[someguy98457]

Had a similar problem with a Sensor+ rack were it would sporadically say "No Data Port A", yet it still passed data to other packs. Reseating the control module fixed the problem.

[willbb123]

Thanks for all the responses.

I don't know, but once did experience a similar situation whereby the output of a Pearl would not pass through an ETC I5M opto-splitter, but worked fine with a different brand. Of course I blamed this on the Pearl and vowed never to touch one again, and I haven't.

Did you reboot both the Pearl and the CEM? Let us know if the problem doesn't correct itself on the A input. A DMXTSTR may or may not have helped in your troubleshooting, but is something everyone should keep in his bag o' tricks.

The pearl isn't my first choice, but is my only option. I did reboot the pearl and the CEM, also shutdown the rack and switched brains.
I will be getting a DMXTSTR, it would of saved alot of time testing cables.

Were you using the 5pin Y cable? I have had issues with some equipment not liking data on pins 4 and 5. I always use the y cables even when I am only using a single universe. FYI for non avo users the pearls have 2 dmx outputs but 4 universes, the second universe is on pins 4 and 5. Dmx output 1 are universes 1 & 3, output 2 are universes 2 & 4. There is a y splitter that you use to separate the universes.

The 2004 has outputs 1&3, 2&4, 3, 4. I was plugged into 1&3 for line 1, and 2&4 for line 2. I'll look into buying/making Y cables. Does the ETC rack even look for data on pins 4/5?

I would guess that it is one of several things. Could be a wounded DMX receiver chip for port A [75176], or damaged or incorrect wiring for port A in the rack. DMX can work correctly when Data- or Data+ is missing, depending on what receiver chip is being used and whether or not the console has grounded or floating DMX common. Then when you add other DMX gear on the same data line, how that gear references ground on DMX common can determine whether the DMX signal works or dies.

Only a guess at this point.

The easiest next step is to swap the two DMX chips in the CEM [75176] if you are comfortable doing this without bending pins. If the problem now shows up on port B, then you have a wounded DMX chip. Yes, it is possible to have a partially function DMX receiver chip.

If that doesn't get it, we should chat before any other changes are made as internal wiring is rarely a problem and other information may lead us to another solution.

David

I have a spare CEM that I switched on site, but that didn't solve the problem. I'm looking at the CEM now, and have no idea what I am looking for. Is there a manual, or can you give me a hint?

[DavidNorth]

The 2004 has outputs 1&3, 2&4, 3, 4. I was plugged into 1&3 for line 1, and 2&4 for line 2. I'll look into buying/making Y cables. Does the ETC rack even look for data on pins 4/5?

I have a spare CEM that I switched on site, but that didn't solve the problem. I'm looking at the CEM now, and have no idea what I am looking for. Is there a manual, or can you give me a hint?

The ETC rack does not look for anything on pins 4/5.

You want to swap the chips in locations U27 [Port A] and U28 [PortB].

See if that works for you.

David

[willbb123]

The ETC rack does not look for anything on pins 4/5.

You want to swap the chips in locations U27 [Port A] and U28 [PortB].

See if that works for you.

David

Thanks, I'll try that on Monday.

[willbb123]

Unfortunately my schedule has been way too busy to open the rack at the shop. I will try to do that before our next show on Friday. I had a concert on Sunday where I had a really strange problem, which is most likely related.

I was doing a 120k rock and roll show, which requires at least 60 dimmers. So I had our 48 channel ETC rack, and a 36 channel Leprecon rack (3x MX2400 in one rack). DMX came out of the borrowed ETC Element console, though 300' DMX snake, into ETC rack, then passthrough to the Leprecon rack. The ETC rack start address was 1 (through 48), the Leprecon rack started at 49.

We were getting ready to start focus, and started stepping through channels on the console. There were some obvious hard patch issues, which I expected because I patched the rack not able to see my upstage truss. After fixing those problems I was still having an issue that was clearly not a hard patch problem. Channel 41 would be brought up on the console, and dimmers 41 and 49 would come up. The ETC rack responded correctly and brought up 41, but the Leprecon would bring up 49 instead of doing noting.

Forgetting about my prior problems entirely, I start troubleshooting at square one. I make the board op confirm the console is 1:1. Run the DMX line though an iso splitter. And finally run dmx through the Leprecon first, then into the ETC.

Lesson learnt (again) the ETC rack does not like passing data. It was really odd looking at the Leprecon rack, "you start at 49, why are you coming on at 41?!?!"

[cbrandt]

Have you tried resetting your rack to defaults? I've had some strange problems with sensor racks when I used them after another show. Really hard to diagnose stuff, but a nice reset is always a good choice. If you can find someone with a dmx tester, that could help you a lot, as well. Something like a Gizmo or Lil Dmxter.