Automated Fixtures Can't switch off lamp: Clay Paky Stage Scan

[tjk]

Hi everyone,

we recently bought some used Clay Paky Stage Scans and are experiencing problems with dmx controlling the lamp.

One of the four fixtures immediately ignites the lamp as soon as the power switch is flipped and the lamp can not be shut down again. The other three scanners do not automatically ignite the lamp and usally allow for switching off the lamp remotely. But sometimes those fail too and can only be shut down by disconnecting power.

We took the one with the most serious problems back to the dealer just to see that everything worked perfectly. But back home the problem had returned. So it seems the problem is with our installation, but i have absolutely no idea where to start looking.

Has anyone perhaps experienced similar issues and can offer some advice?

Thanks,
Thorsten

 

[TheDonkey]

Try possibly re-patching them to a different set of channels on the console? It may be spewing bad information.

Is the DMX string terminated?

 

[tjk]

We even tried a completely different console with no effect.
The DMX Bus is terminated, but the lamp becomes ignited on power-up, even if dmx is not connected at all. Everything else, except lamp control, works fine.

 

[JD]

Well, usually there are two things that control a lamp strike. (Barring a true part failure.)

The first is usually on the menu on the fixture. It can be set to default strike at power on.

The second is the "lamp on" and "lamp off" on the DMX. The only trick on number two is that the board must hold a certain value for a number of seconds. (Usually 3 seconds.) If for some reason, the board is varying the DMX value, even if only by one or two, the light will not respond to the command.

If the unit worked fine at the dealers, then I would suspect something is causing the fixture to see a varying DMX number. Try using just the board, a short DMX cable, and a terminator. If the oversimplified layout fixes the problem, then you have a line noise or grounding problem.

 

[porkchop]

It should be controlled by one of the 8 dip switches on the back of the unit. The reason that they returned your unit to you and said it works fine is because it does, it's just setup with different options. Ours are setup to strike as soon as they receive data and cannot be reset from the board (not optimal but I'm not the one that made that decision). Check your dip switches and bench test it with and without data and tell me what happens.

 

[tjk]

The first is usually on the menu on the fixture. It can be set to default strike at power on.

There is no such thing as a menu, only a bunch of DIP switches. The two of them, that are lamp-related, are labeled:

Enable/Disable and 5-Min-Lamp-Off/Lamp-On-Off

I have them set to Enable and Lamp-On-Off. Those settings are the same for all 4 fixtures so i guess this is correct.

The second is the "lamp on" and "lamp off" on the DMX. The only trick on number two is that the board must hold a certain value for a number of seconds. (Usually 3 seconds.) If for some reason, the board is varying the DMX value, even if only by one or two, the light will not respond to the command.

Well, lamp control with the stage scans is really simple. There is a dedicated control channel with the simple logic of
value < 128 => Lamp Off
value >=128 => Lamp On
The dealer had shown me that everything is fine with some of those cheap "DMX Scene Setter" 24 Fader Controllers and it was pretty much like fader up, the lamp goes on fader down and off it goes. I really felt rather stupid when he did that

Try using just the board, a short DMX cable, and a terminator. If the oversimplified layout fixes the problem, then you have a line noise or grounding problem.

I will do so, the next time i get there. But i really don't think DMX is the issue here, as the lamp is even ignited with no dmx connected, something the other (identically configured) scanners don't do.

It should be controlled by one of the 8 dip switches on the back of the unit.

There are 16 dip switches. 10 for the address and additional 6 option switches

The manual states

Option 2 ON Lamp control and recalibration disable
Option 2 OFF Lamp control and recalibration enable
Option 3* ON Lamp control (channel 17) enable
Option 3* OFF Lamp off after 5mins blackout; channel 17 disable

*Option is enabled only with option 2 OFF.

So I set switch 2 OFF and switch 3 ON.

Check your dip switches and bench test it with and without data and tell me what happens.

Lamp is ignited as soon as i flip the power switch, even with no dmx connected at all. The 3 other fixtures do not ignite the lamp with no data.

Whew. Sorry for that long (and sometimes redundant) posting. And thank you very much for your help.

 

[PRGDistributionTechServ]

Hi Thorsten

Please confirm that you have the switches set with 2 off and 3 on for Lamp Strike control

I would toggle the switch on and off to confirm it is working. I have seen these switches become contaminated and look like they are set to a position but not respond so. Sometimes they are so bad they need to be replaced.

Option 2 is to enable (OFF) or disable (ON) the lamp control and the re-calibration
Option 3 is active only if option 2 is OFF.
If option 2 is ON, then the option 3 is inhibited (useless, does nothing), the lamp is continuously ON and the effects don't re-calibrate when all the channel levels are at 0%.

Reading your responses however it really sounds like this is a patch issue. Please confirm that the console patch exactly matches the fixture settings in both fixture mode (there are two libraries, one for lamp strike one without) and DMX address. Its not like a grenade and being close doesn't count. Actually being close causes the problems you are describing. You can confirm this by addressing the questionable unit the same as one that is responding correctly.

John A Maher\

PS These boards use the mains ground as a referance so make sure that is good too

 

[tjk]

Hi John

Please confirm that you have the switches set with 2 off and 3 on for Lamp Strike control

Well, I'm pretty sure they are set like you said, but i will check it again.

I would toggle the switch on and off to confirm it is working. I have seen these switches become contaminated and look like they are set to a position but not respond so.

At least mechanically they appeared to be fine when I tried every possible combination But to actually check they are switching anything might be worth trying. As far as i remeber the switches are only plugged into some kind of socket, so it should be easy to use a multimeter and test if they need to be replaced.

You can confirm this by addressing the questionable unit the same as one that is responding correctly.

That's something i will definitely try. Why dind't I come up with this by myself?

-Thorsten

 

[00AVD]

Just a thought - are they all the same firmware revision?

 

[tjk]

Just a thought - are they all the same firmware revision?

I actually got no idea at all, but i think it's likely there are different versions. But i will have a look at it the next time i get there.

 

[tjk]

Hello again...

Well it took some time, but i finally managed to test all the things you suggested. But I still had no luck getting things to work - instead now a second scanner shows the same deffect.

What I did first was to set the scanner to the same address as the one right next to it. The result is still the same: While one scanners lamp can be controlled without any difficulties, the second scanner immediately ignites the lamp on power on and can not switch it off again. So it seems not to be any patch related issue.

Next i tested the dip-switches with a multimeter and all the switches are working properly. I did not test if the connection to the circuit board is fine as i can't do this without disassemling the whole thing which would mean i had to get the scanner down on the ground...

I even borrowed some cheap 2 preset dmx controller and connected the offending scanner as the only device. But none of this worked.

I tried to find out the respective firmware versions of the scanners. The manual states the version, and some counters (lamp hrs, ignitions, etc) are displayed on power on. Well, my fixtures display the dmx-address and nothing else...

Any ideas?

-Thorsten

 

[porkchop]

Looking at our "road modified" lights that are 10+ years old I realized that most of the safety features (like temp and lamp cover sensors) have been over ridden. You might be seeing a similar situation. You might open up the back of a unit that works the way you want and the one in question and make sure the cable bus looks the same. If memory serves some of the cables to sensors and such are the exact length needed to bypass them. If you really want to dig you might be able to find a wiring diagram.

 

[porkchop]

You haven't come back so I assume you found the solution to the problem. But for a better answer than my last one, if you bypass the relay on the back of the strike card stage scans will strike as soon as are turned on and stay struck till they are turned off

 

[tjk]

Hi,

sorry for not answering that long. I just had no chance to get the scanner on the ground, yet. And as I don't feel that comfortable up on a ladder, i won't do any repairs this way. But I think friday i will finally manage to further look into this. (It's not my day job and i'm only there once a week, so everything takes a little longer)

I will most definitely have a look at the relay you mentioned, although I don't think a intentional modification is the cause. It worked like a charme when i returned it to the dealer to complain...