iDMX 1000 Connections

[Denny]

This will be my first year using DMX and I am trying to determine what hardware I need to make the connections to LOR. I will only be using a moving yolk this year but am not sure of the best way to connect it to the LOR system. I have the USB485B adapter, so is it better to have a longer run of Cat 5e from the adapter to the iDMX 1000 and a shorter DMX cable to the fixture or should I get a longer DMX cable and keep the iDMX 1000 closer to the USB485B? Since the USB485B has two ports in parallel, I assume that I can connect the iDMX 1000 to its own port on the adapter.

Just for my own knowledge, if I wanted to connect the iDMX 1000 to other LOR controllers, does it make any difference where it is connected in the chain, i.e., beginning, middle, end?

[Steven]

I haven't used DMX, but I know that both DMX and LOR use RS485. DMX is 250 kbit/s, while LOR has 3 possible speeds. Theoretically, if you used LOR at the lowest speed (which I believe is 19.2 kbit/s, please correct me if I'm wrong), you could run it further than DMX. In practice, it shouldn't make any difference.

It makes no difference in what order you place LOR devices on the LOR network, since the RJ45 jacks are simply wired in parallel.

[-klb-]

From a practical matter, Cat 5 cables for LOR are better matched to the RS-485 requirements than microphone cables are for DMX. Cat 5 is also great for DMX, but then you have to get the connections made.. So it may make more sense to keep the DMX side short, and let the Cat 5 LOR run take the length.

One restriction on Cat5 length to the iDMX is when the iDMX is being powered from a USB-485B or nearby LOR controller. In those cases, per the manual, the iDMX should be within 50 feet of the device providing power. This would not apply if an external DC power supply is used with the iDMX.

http://www.lightorama.com/Documents/iDMX-1000_Man_Web.pdf

I see nothing technical, nor in the iDMX documentation to prevent the iDMX from being anywhere in the LOR RS-485 chain of controllers. If you have suitable weather tight enclosures available, out near one of the normal LOR AC controllers would probably be ideal, as then the AC controller will power the iDMX..

- Kevin

[Denny]

Steven & Kevin,

Thank you for the input and advice. Since I place my LOR controllers throughout the display, I will just connect the iDMX to the nearest controller. Since I will be using a yolk out in the display and have to build a water tight enclosure for it, I will make it large enough to contain the iDMX also. This year, I will only have the one fixture, so that makes the most sense to me. Next year, well, that may be a different story.

[zman]

Denny,

I would not worry about the length of each. The iDMX is meant to be in series within your controller network, or, because the USB485B has 2 ports. you can run in parallel no problems either way. Be sure you terminate your yoke or last device. If not built into the yoke, you can buy or make one cheap. If you keep your DMX universe small, you may not have to worry about microphone vs. DMX cables. I am still trying to get a good feel, but what I have found, is that if it is over a few hundred feet, DMX and termination will help eliminate erratic behavior. Cheap preventative maintenance in my book.

Out of curiousity, what are you going to do to waterproof your yoke? Keeping the iDMX out of the weather is going to be a good idea along with your yoke.

Mark

[Denny]

zman wrote:

Out of curiousity, what are you going to do to waterproof your yoke? Keeping the iDMX out of the weather is going to be a good idea along with your yoke.

Mark

Last year, I saw an enclosure that someone made on PC. I think I will build a similar one. I can't remember who made it or find the thread at the moment (I am still having trouble learning the new forum on PC), but it was basically a cylinder of plexiglass with a fan in the top. I am also thinking of getting half of a plastic 55 gallon barrel from the feed store and cut an opening of sufficient size to project through. Then, place a thin piece of plexiglass over the front opening. I don't have anything on paper yet, just pondering different ways to do it at the moment. My wife did a very large toy soldier cut out last year (over 8 feet). I was thinking of building a guard house for him to stand in front of and then mounting the yolk and barrel to the back side of it.

I haven't been able to "play" with the yolk yet. First, I am waiting for the sale to get the iDMX 1000 and secondly, the yolk was damaged when it was delivered last week. A replacement is supposed to be on the way. I'll keep you posted on the waterproofing plans.

[zman]

Denny,

That was Mike Liquori's Nutcracker design. Great minds think alike. I too have the to-do to create 2 Nutcrackers for my 2 yokes as well. Instead of 55 gallon, I have acquired 30 gallon barrels. The plexiglas approach is the same. Send me a PM there is some other items you need to consider and I can outline.

If you need, I have a source for plastic or metal barrels.

Mark

[bhays]

Denny wrote:

Last year, I saw an enclosure that someone made on PC. I think I will build a similar one. I can't remember who made it or find the thread at the moment (I am still having trouble learning the new forum on PC), but it was basically a cylinder of plexiglass with a fan in the top.

That may have been my enclosures that you saw. I missed Mike Liquori's... does anyone have a link?

http://lightorama.mywowbb.com/view_topic.php?id=14577&forum_id=75&highlight=moving+head+enclosure

[Denny]

That's it, that's the link I was talking about. Thank you.

I think you modified the vents on the top with a sort of inverted "P" trap too. We don't get snow but a lot of blowing rain in December, so tht seems best for me too. Why mess with a proven technique. Thanks for posting it again.

[bhays]

Denny wrote:

That's it, that's the link I was talking about. Thank you.

I think you modified the vents on the top with a sort of inverted "P" trap too. We don't get snow but a lot of blowing rain in December, so tht seems best for me too. Why mess with a proven technique. Thanks for posting it again.

Yeah, I just used a floor flange and a trap...

[zman]

Yup, sorry Brett, I do remember your thread and have it bookmarked. I was also on PC talking about making Liquori nutcrackers as my housing. I confused the 2 thoughts. The tree method is the one the Mike Ziemkowski did in SoCal as well. I talked to him about that.

So you moved the fans to blow outward, that is interesting. Did you have to worry about condensation at all? How did the fixture hold up and react to the cold weather you have in Indiana? I have been talking about this to Wirekat. We were wondering what the effect of the moisture in the air would have on the yoke. I guess with air blowing out, that may have kept a lot of that from entering into the enclosure.

[bhays]

I didn't have any problems with condensation at all. Honestly, these enclosures worked out great... not much to change.

This year I am going to a truss setup and have to figure out a new approach, however.

[Denny]

Bret,

After you made the lexan cylinder, how did you attach it to the metal rings of the base and top, or do you just place the cylinder inside the base and drop the top onto it? I would assume that you used silicone to seal it to the base but just let the top rest on the top of the cylinder so that you can get to the yolk inside?

[bhays]

Actually, I didn't seal either end, just set the ring in the base then set the top on. Worked fine... It's not like a vacuum chamber, I think some breathing is a good thing.