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What is going to be the new DMX?


musht

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Partly prompted by Dave Hallet`s quote in the switch thread;

 

"30,000 DMX channels pixelmapped over 79 streams of DMX on broadcast ArtNet"

 

Wondering what the emerging standards are for driving things like large arrays of pixels?

 

DMX seems to be running out of puff for this sort of application, only run 170 RGB channels per 512 channel universe.

 

Currently seem to be going to Artnet or E1.31, as far as understand streaming ACN will actually be E1.33 and isn`t finished yet(?).

 

Then from Artnet/E1.31 to DMX to pixel protocol.

 

Confused at the hop back to DMX?

 

Some sort of video to pixel protocol would seem to be a shorter hop.

 

Don`t think DMX is likely to disappear anytime soon but...

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I don't think DMX has a great future for controlling video directly - a HD video signal is 2,073,600 pixels, which would need 12197 DMX channels. This isn't sensible! However, using DMX to control a video server is a different thing altogether.

 

12197 Universes even ;)

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Art-net has pretty much won out as the "standard" for DMX over Ethernet - for low res LED being pixel-mapped using DMX, Art-Net is the current standard, and I cannot see that changing for a while - this is probably because Art-Net has very low overheads, you basically strip each pixel down to it's 8 bit RGB values and shove some header information on the top and send. Decoding on the other end is a matter of filtering out the packets you need (based on header info) and rendering out the raw values.

 

You generally will not go from DMX to Art-Net to DMX to control processors.

 

Most of the 79 streams mentioned in the article mentioned are almost certainly sent directly from a media server. 79 streams traveling down a single cat5 cable, no break-out and break-in boxes. Media server pixel maps the desired pixel space, renders out the values straight into an Art-net stream, sends it over cat5 to the control processor rack which maps the Art-net to the pixels.

 

sACN is an interesting one - more and more fixtures are coming out ACN ready, but I don't think we have seen an ACN ready console as yet. sACN was meant to be a bridging protocol - one which also fits nicely inside of ACN... It is very neat and tidy, but the industry will probably be more than happy to just skip sACN and jump to the big-boy when it is fully fleshed out. After all, all fixtures that I know of which are ACN ready can accept Art-net. If you have already made an investment into Art-net compatible devices, why would you change and why would you split your network up? After all, sACN does not offer any mind blowing features (ACN though... that's another story)

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Couple of corecctions to the OP.

 

ArtNet is not a published standard and does not have an ANSI designation.

It's a proprietary protocol that allows royalty-free usage, and did indeed become a defacto standard by virtue of being the only royalty-free one. (It's also a really bad one, as any network admin will tell you. It doesn't scale well either, as the ArtNet II document makes clear.)

 

ANSI - ESTA E1.31 is Streaming ACN, also known as Streaming DMX.

It is a published standard.

 

E1.33 doesn't exist (at present), and it's simply a way of doing RDM over Streaming ACN.

 

ACN (E1.17) and Streaming ACN are quite different protocols.

 

ACN is a protocol allowing Get and Set of arbitrary properties. At present, it's only being used for error reporting and configuration of devices. While it can easily be used to set values for Intensity, Pan, Tilt etc, this hasn't yet been done.

 

Streaming ACN is a pure DMX-over-Ethernet protocol.

It uses an ACN wrapper, and is logically a multicast 'Set' that applies to up to 513 attributes (start code plus 512 channels).

However, when implementing it none of that matters - the header is very simple and it's actually much easier to implement than ArtNet II.

 

(I've read both documents - sACN is *so* much easier than ArtNet II. I don't actually think that anyone has implemented ArtNet II, only the original ArtNet.)

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The Christmas light brigade have just discovered DMX as an alternative to their proprietary protocols, and they've jumped straight to E1.31, streaming DMX over Ethernet, and they're using lots of channels for pixel addressable stuff.

 

Expect Art-Net to be of historic interest only in a few years.

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I don't think we have seen an ACN ready console as yet.
Any console with a working ethernet port could be called 'ACN-ready'. Much like "HD-ready", the term is meaningless.

 

However, Eos, Ion, Element and Congo are all ACN (E1.17) consoles right now, and it's being used for error reporting and Timecode/MIDI/Serial/etc-over-ethernet.

At the moment there are precious few ACN devices though - I know of the ETC products Sensor+ and NET3/ACN Gateways, but precious little else.

 

As for E1.31 Streaming ACN, it's on the above (of course), plus the GrandMA II and WholeHog 3 consoles.

According to the marketing, it's also on the Strand Palette though I've not seen one working yet.

 

I'm unsure if it's on Chamsys MagicQ or the newer Avolites consoles yet, though I expect they're already working on it.

 

I would be very surprised if E1.31 wasn't on all 'in production' network-connected lighting consoles by the end of 2011.

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Currently seem to be going to Artnet or E1.31, as far as understand

streaming ACN will actually be E1.33 and isn`t finished yet(?).

 

E1.33(RDM Net) is now making good progress and will add momentum to E1.20 (RDM over DMX)protocol.

See PLASA CPWG Report

 

The ability to get feedback from fixtures as well as control them is the new DMX.

DMX is not best employed for Video streaming, especially with the introduction of RDM.

 

Always be aware that DMX over ethernet compliments DMX over 485, it does noty replace it!

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Always be aware that DMX over ethernet compliments DMX over 485, it does noty replace it!

 

Yes and no... It is theoretically possible to run extremely complex shows without ever going to an RS-485 network. Main issue is that a bus topology is such a nice way to run a data network for shows that it would be a bit silly to not DMX between fixtures (at the moment).

 

Many dimmers can now accept various ethernet protocols. Fixtures are now coming out which are capable of using ethernet protocols. If I had an aversion to XLR cables, it is entirely possible to plan a rig that does not need any.

 

A major stumbling block for ethernet protocols is the star based topology that current technology uses. You cannot just y-split an ethernet cable, you need to use either a switch or a hub. Some fixtures get around this by putting a 3 port hub in their fixtures... The problem with this is that when a fixture looses power, so does the hub - the rest of the chain will then have no network connectivity either. Each hub also adds a small bit of lag. 30+ fixtures and it starts to get a bit noticeable.

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Thanks for the replies.

 

Understand that Artnet and E1.31 are different protocols,found a brief run down on E1.31

 

http://www.plsn.com/index.php?option=com_content&task=view&id=4897&Itemid=54

 

Still slightly confused as to where ETCnet fits, is this a proprietary protocol or ETC`s range of hardware that supports E1.17 and E1.31?

 

Can see that topology has its part to play, daisy chain easier than star in a lot applications.

 

Need to see some heavier duty Cat5 cable and connectors appear , not sure ethercon is a great solution...

 

Converting video to huge amounts of DMX streams still seems a long way round though.

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ETC Net has gone through 3 generations - Net3 is an ACN implementation - primarily sACN with support for their MIDI/Timecode/... boxes via ACN. Net2 was a proprietary DMXoE/Processor expansion solution... The original Net, I have never experienced and know little about.
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Always be aware that DMX over ethernet compliments DMX over 485, it does not replace it!

 

That's not right. You can buy use E1.31 from PC to some lighting controllers (pixel interfaces, etc) right now. More Ethernet (E1.31) input devices (dimmers, etc) are coming to market this year.

 

I do think that DMX over RS485 connections will be around for a while yet though.

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