DMX Universes and addressing

[icewolf08]

-) in the rest of the world, a channel is simply a control channel or the equivalent of 1 dmx address. a fixture is a number of channels/dmx addresses that the console groups together and maps to controls such as encoders. in the ETC world, a channel can be a dimmer or an entire moving light. in the wider world, most consoles have a way to assign a unique fixture or channel number to a device to ease data entry. it seems ETC has bypassed this step by calling everything a channel.

This isn't really true. Strand has been doing this at least since the release of the 500/300 series desks. Everything gets a channel. It makes way more sense than having CHANNELS for conventionals and FIXTURES for moving lights and devices. This allows you to patch every intensity in a logical order and not worry about what attributes are associated with that intensity, be it just a conventional on a dimmer, a unit with a scroller, or a full blown moving light. You don't have to call: "channels X, Y, and Z AND fixtures A, B, and C out" you can just call a range of channels, much simpler.

When Fred says he likes to start his channels a 1001 for movers, the console has to have more than 1000 channels to do so. yours only has 250, so it would be impossible on your console in any case. on a higher level console, one could make the unique fixture number anything, since it's different than the control channel. in that case, on a hog or grandMa for instance, one could easily start their movers in the 1000 range.

Again, not really true. You have 250 channels, but there is nothing that says that those channels have to be 1-250. You can use 1-50, 101-150, 201-250, 301-350, and 1001-1050 if you want, as long as you don't exceed 250 active channels.

 

[TimOlson]

Hey Alex! I re-read the manual concerning patching, and it didn't cover renaming channels at all. I know how the older express/expression line works, but I'm not so familiar with the newer stuff. so I called ETC tech support and spoke with Tracey. He didn't know the answer right off the bat, but was able to walk over to his Element console and give it a try. According to Tracey, it's not possible to re-number the channels on this desk. a 250 channel console will allow channels 1 through 250 and that's it.

as far as ease of use - there are so many different approaches for so many different uses that I was certain to rub someone the wrong way. I think we basically agree that it's better to avoid bouncing around between "channel" and "fixture" -- the way I do this is to either give everything a unique fixture number (hog) or to make everything a fixture (grandMa). that being said, if I find myself typing in any series of channels more than twice I simply make a group palette and choose things that way.

Tracey was also able to share with me some of the foundations of why things are the way they are in the ETC world: most of it comes from user feedback. Tracey also mentioned that everyone has an opinion that they believe to be the right one!

it is interesting to see how different products evolve; the ETC & Strand line of consoles has a much greater presence in Theatre than it does in the corporate events world that I live in, and the requirements are quite different.

peace,

Tim O

 

[derekleffew]

...
-) if you have more than 32 dmx devices you must use another universe. ...

Or an opto-splitter, as the 32 device-load limit is per data stream, not per universe. Theoretically, one could put 32 devices on each output of the splitter. As most splitters only have five or six outputs, one can also plug one splitter into the output of another to gain more.

...Channels on the Element correspond to one device, regardless of how many attributes it consumes. You might have a 30 address moving light, but it only takes up one channel. The Element has 250 (or 500) channels, but 1024 addresses (also known as attributes).

I'm not sure this is true. We had this confusion when discussing the Strand Basic Palette, which comes with 100 channels. That console would only be able to control three of your theoretical fixtures having a DMX footprint of 30 channels, not 100.

...If you have 4 movers that have 25 attributes each, then that will take up 100 channels. Every control parameter takes up a channel. Intensity, pan, tilt, color, gobo...etc. ...

I suspect the same is true of the Element 250. The number of outputs (1024) would seem to indicate it can control thirty-four 30-channel fixtures (34*30=1020), but I suspect it's limited by the channel count to eight (8*30=240). Anyone from ETC want to clarify?

 

[jmabray]

I suspect the same is true of the Element 250. The number of outputs (1024) would seem to indicate it can control thirty-four 30-channel fixtures (34*30=1020), but I suspect it's limited by the channel count to eight (8*30=240). Anyone from ETC want to clarify?

As far as I know that is not true. You should be able to control up to 34 thirty channel fixtures on an element. (At that point I start to wonder why your aren't buying an ION, but I digress...)

A channel is a channel. It can be a single conventional fixture, a conventional fixture with a moving mirror attached, a moving light, etc, etc....

An output (what used to be DMX addresses in ETC's world)or several is what makes up that channel, but you are only limited by output count, not by channel count.

 

[Corbettlight]

No, you're limited by both channel count and output (address - it's still an address on the new ETC consoles) count. The Element 250 had 1024 addresses and 250 channels. Both things limit you. You could have 250 conventionals (and the channels limit you, as you are only using 250/1024 addresses), or you could have 34 30-parameter moving lights (and the addresses limit you, as you are only using 34/250 channels).

 

[jmabray]

While channels are a limiting factor, they are not in the same way that they are on those Strand consoles that Derek was reffering to. That was where I was trying to draw the distinction.

Sorry for the confusion.

 

[fredthe]

When Fred says he likes to start his channels a 1001 for movers, the console has to have more than 1000 channels to do so. yours only has 250, so it would be impossible on your console in any case.

While this may be true for some specific consoles, it's definatly not true in the general case.

On many modern consoles, channel numbers don't have to be consecutive. So, if you only had 250 channels, 100 dimmers, and, say 10 movers, you could assign your dimmers to channels 1-100, and your movers on channels 1001-1010. You are still using less than 250 channels, as the numbering is arbitrary.

Edit: I just spent some time with the Element OLE... it looks like you are restricted to consecutive channel numbers so this wouldn't work for the Element. Do the EOS/ION have the same restriction for channel numbering?

-Fred