Ethernet

[joshread]

Hi All

 

I recently used a frog 2 lighting desk for a production and noticed and Ethernet port on the outputs section. I have also seen various references to Ethernet in various books/magazines and on this forum. I was just wondering what the difference between Ethernet and DMX was, and how it is used in lighting systems.

 

Thanks in advance

 

Josh

[gareth]

That's a huge question - requiring an answer that's probably too detailed to give in the form of a forum post (and anyway, the BR is a technical entertainment forum, not an IT/computing one). I suggest you start by reading this, and take it from there.

[jhaynes199]

Ethernet will become the industry standard give it a few years. Watch this space.

[tokm]

On the Hog2, it be for the Overdrive box (more DMX universes basically)

 

Hog3, its for more DMX universes & for linking to other hog kit (or so Ive been told)

 

And yes, must agree with jhaynes199's sentiments, its already being used for dimming, remote access panels, DMX around buildings, see; strand show-net and ETC's Ethernet stuff.

 

Its obvious why its going to get used, cheap to use (cables/connectors), the possible data rate is crazy (heard it could potentially handle tens if not hundreds of DMX universes) and as lights will do more things like video projection and talk back to desks, a new form of all in one data cable will be required. On the strand 500 desks, ive seen warnings come up when a dimmer module in a SLD90 rack is unplugged or trips AMAZING is all I can say..

 

Funny though, VL were already doing this years ago!

 

Tom

[dbuckley]

With the Hog3, your entire system is Ethernet based. Ideally, the boxes that convert Ethernet to DMX512 (the DMX processor, generates 4 univeres of DMX512) are placed near the lights themselves (ie on stage for the movers, or in the dimmer room or racks) and all ther wiring from desk(s) to rack units is Ethernet. Its completely different from runnng DMX512 out of the back of the desk. Also timecode comes into the Hog3 through a rackmount box connected to the Ethernet network.

 

In years to come, movers and dimmers will have ethernet sockets on them and that'll be the end of DMX512.

[Ben...]

In years to come, movers and dimmers will have ethernet sockets on them and that'll be the end of DMX512.

 

...just as soon as a common standard (de-facto or otherwise) emerges

[peter]

Hi Joshua

 

The Ethernet port on the Frog 2 is used to transmit Artnet which is just one of many ethernet based DMX standards. The Ethernet signal from the Frog 2 carries all 4 universes of DMX information down a single cable, enabling you to tap into a buildings existing ethernet network or run a single FOH 'multi'. You can then 'break out' the ethernet signal using one of many Artnet-DMX conversion boxes (we use the Net Lynx O/P by Artistic Licence). These Artnet-DMX boxes can convert several universes at once, so are ideal to be placed near the dimmers, near the fixtures, etc.

 

Artnet (and other ethernet standards) can also be used for connecting a console to a visualiser, which saves you having expensive DMX input boxes connected to your pc.

 

If you want to know more about Artnet, take a read of the spec, which is very detailed :D

 

Other Ethernet systems include Strand Shownet, Pathport and ETCNet2. Artnet is by far the most popular system, primarily due to its open-source nature which means that anyone can implement it into their products without licence fees or copyright issues.

 

I hope this is the sort of information you were after. Please feel free to get in touch if you've got any further questions or queries on the Frog 2 or any Zero88 products.

[dbuckley]

...just as soon as a common standard (de-facto or otherwise) emerges

 

Sure, but we got past that hurdle to get DMX512, and I'm sure we'll get past it again for Ethernet.

 

But, even if we dont, it doesnt matter, 'cos we can have several different incompatible standards on one network (ie one cable) all at the same time (as long as the protocol is not brain-dead at birth, like the first version of ArtNet was), so the chances are that Artistic Licence will build the mother of all protocol converters...

[gareth]

On the Hog2, it be for the Overdrive box (more DMX universes basically)

Wrong, I'm afraid. Hog2 overdrive boxes have nothing to do with ethernet - overdrive is simply a way of piggy-backing one DMX stream on top of another (available on three out of the four DMX outputs on a Hog2), with the overdrive box being the means of deciding the extra stream.

[Andrew C]

...just as soon as a common standard (de-facto or otherwise) emerges

Just how badly could M****n screw this one up? RJ11 connectors with 7pins, all in a different order depending whether the device is in send or receive mode... And that's just the hardware!

[joshread]

Thanks guys for all your reply's.

 

I am beggining to understand it a bit more now.

So basically if it became standard it could cut out the need to run 4 DMX cables from the desk to the dimmers/movers etc? so cutting down on the cabling. that would be really useful!!

 

Thanks Peter for your reply about the frog 2 it will settle a few arguements I had with my school technician!!!!!!!

 

So if you could link it up to a network system in a building does that mean in theory you could control your console remotley from any room in the building?

 

Thanks again

 

Josh

[dbuckley]

So basically if it became standard it could cut out the need to run 4 DMX cables from the desk to the dimmers/movers etc?

 

Yup. For those with the big bucks thats available today.

 

So if you could link it up to a network system in a building does that mean in theory you could control your console remotley from any room in the building?

 

Thats a slightly different question. The previous answer relates to (I'm fudging this a bit) replacing one or many DMX512 cables with a single ethernet cable.

 

Taking the Hog3 as an example, the DMX processors actually have all the control smarts in them, and the Hog3 desk just downloads the show elements to the DMX processors, and then sends control information to the processors. Thus the Hog3 console isn't actually working out (say) 200 universes worth of DMX data 44 times a second, 50 boxes are each doing 4 universes worth of calculations and updates.

 

Once you've got one Hog3 in command, you can then have more Hog3s in on the party; they all can share the same show, and you can drive your show from anywhere.

 

I should say at this point that firstly, neither of thee concepts are unique to the Hog3, and secondly the Hog3 system costs a shedload of money, but in a few years, when the Ethernet dust settles, everyone's console will have an Ethernet port on the back, and this type of flexibility will trickle down. Around then it's likely we'll see some new manufacturers appear. As everyone knows, all this stuff is done in software, and manufacturers place products in the marketplace by product set they are willing to deliver for a price, which has little to do with what they could do. The new players will shake this up a bit, just like (for example) Zero88 did a few years back, prior to them being part of the "old guard" :D

 

As an example, have a look at the LanBox, which is a really competent and very low cost lighting controller complete with an Ethernet port, with some less good software that likes to run on a mac. What LanBox lacks is a desk control surface. However, if such a thing were to appear then using that to control a veritable fleet of LanBox units would provide a low cost, powerful, distributed control system, all Ethernet based. Its not as complete, complex or as big as a Hog3, but it may well be enough to displace other consoles...

 

We live in interesting times...

[musht]

Wayne Howells of Artistic Licence has written a book on use of ethernet in entertainment:

 

http://images-eu.amazon.com/images/P/1904031293.02.MZZZZZZZ.jpg

http://www.amazon.co.uk/gp/product/1904031...39&v=glance

 

Moderation:Book link changed to Blue Room Associate one.

[andy_s]

I'd just like to say, without going into the technicalities of the system, we decided to save a significant amount of money on our new building by cutting the building-wide DMX tielines, which had originally been specced alongside the cat 6 network.(which we wanted in order to "futureproof" the installation. As we were going to tender, it became apparent that the price of DMX nodes which convert the data from the ethernet to DMX had come down in price substantially, so we replaced the whole DMX network with 4 of these and save alot of money. So far (we've only been open since december 05) we have not had any problems with controlling DMX devices like MACs, smoke machines, etc etc. the only small issue is the dimmers still go looking for a DMX signal, and show a fault when they don't find one, even though they are functioning perfectly well without it.

 

Financially speaking it made sense for us as we were reducing the size of the overall installation. if it was a straight choice of either DMX or ethernet, I'd probably try to find budget for nodes and go for ethernet, as this would in the long run be cheaper than installing DMX then retro-fitting the ethernet.

 

regarding temporary installations, I'd assumed that DMX was preferred for being more robust, but other posters elsewhere have testified to the suitability of ethernet for temporary set-ups.

[dbuckley]

Wayne Howells of Artistic Licence has written a book on use of ethernet in entertainment:

 

Without having read the book, I'd not recommend it on the basis it comes from the (generally excellent and highly recommendable) Artistic Licence, who came up with ArtNet. The original implementation of ArtNet used a method of addressing that anyone who knew anything about Ethernet networking would know was unacceptable, based on the learnings of history. Another one-time very popular Ethernet protocol, DECNet, used the same type of scheme some decades earlier, and it was a right royal pain in the you-know-where, causing strife to network engineers around the globe. Given that association, I find a stretch that the book will be full of good advice.

 

Current ArtNet has dropped this evil address association (but not by default, you have to select it), but its such a heinous thing to have done that the otherwise wonderful Artistic Licence are not forgivable on this issue.

 

The bigger problem is that as ArtNet was out there early and generally works, it got traction, so it'll be around for a good few years yet.

 

[/rant]