Lessons learnt DMX over IP.. Part(1) there is standards / there is no standards

[mrpackethead]

I have not. But you've got me curious now, and it shouldn't be hard to test.

It will be interesting to see where the go no go point is.. Just to make it a useful test, can you specify the frame rate to be 40fps

I have to admit that the E16 family of products starts having issues at 43 universes of E1.31 under vs 3.1 code.... With vs 4.x code an IGMP it should scale to 1000's.. Its making me think though that i might be able to do a bit more trickery up the front end, and use some multicast hash filters.. though i think there are only 4, so that limits the number of universes...

[nomis52]

This thread is quite frustrating to read...

If a receiver does not support IGMP it does not support E1.31. Period. You can't support half a standard and expect things to work.

As a customer I'd take the devices back to the manufacturer and tell them you either want a patch fix or your money back. Otherwise it's like buying a car with only one gear and expecting it to perform well at all speeds.

Simon
(PLASA Standards Member)

[caretaker]

MrPackethead thanks for starting this post, although I have a limited knowledge of networking and electronic design topics such as these deeply interest me as they spur me on to learn a little more and maybe look at something in a new way.

[mrpackethead]

This thread is quite frustrating to read...

If a receiver does not support IGMP it does not support E1.31. Period. You can't support half a standard and expect things to work.

Well yes, but as you well know the difference between "standards" and "reality" is somewhat different, and this is what the entire thread is all about. And i for one, as a manufacturer, am working very hard to bridge the gap between the reality and the standard, and 'better' support of the standard is coming in the next major code release ( its under testing now )..

As a customer I'd take the devices back to the manufacturer and tell them you either want a patch fix or your money back. Otherwise it's like buying a car with only one gear and expecting it to perform well at all speeds.

Fortunately our customers are much more interested in "does it work" than does it comply to a standard. If it works and does the job that they need it to, is it a problem that it does not comply? This is the trade-off often made.

How many devices out there, that are 'DMX' are actually really 'DMX'? Sometimes good enough is good enough.



Simon
(PLASA Standards Member)[/QUOTE]

[mrpackethead]

One could also argue ( and theres been some pretty big arguments ) that the e1.31 standard was pretty poor. The biggest thing that annoys our clients is that they have to be able to configure "complex" networks. i put complex in quotes because these guys are lighting guys, not networks guys..

[Zeph]

In a do it yourself hobby niche, it's not surprising if some of the projects are "based on a true story" as the movies say, with a bit of license. I'm OK with that.

I like that the sharp eyes here do often point out safety issues (like power traces too close to logic in proposed circuit boards); compliance to some standards and norms is more important than others.

However, it would seem to be a good thing if these devices were clearly labeled in regard to how much of a standard they follow - whether DMX512A or e1.31 or RDM or whatever. And maybe they should be clear up front that they implement PART of the standard, rather than even accidentally implying they have done it all (correctly). I don't think however that use of "DMX" or "sACN" should be prohibited, because it's very useful and meaningful to know that the Pixad8 or e680 take something resembling e1.31 as their input protocol. There just need to be some disclaimers.

I suspect this is one reason one of the designers in our little niche labels all their products as being prohibited from commercial use. If his DMX product is not exactly correct, well you have been warned; meanwhile there are a lot of satisified users.

But, alas, even in the professional and commercial part of an industry, it's common to fail to fully implement a standard. Not just in lighting, either. When it really matters, an industry tends to have formal testing and certification, but those raise costs. Not just the cost and bureaucracy of doing the testing, also the hidden cost of reducing the competition. Sometimes certified and uncertified products co-exist and the customer can decide which to use depending on need.

Good can-o-worms to bring to light, MPH.

[mrpackethead]

Yeah Zeph, i agree with you. Though, on this one, we've dropped the ball, so we gotta fix it. As simon says, if its not speaking IGMP then its not standards compliant.

[zman]

Thanks guys, this thread was a a bit over my head, but I think with the way things are going in this hobby or ours, it is going to get important for us all to have some working knowledge of the limits, and how possibly to address them.

[mrpackethead]

zman.. the only question that is dumb, is the one you don't' ask.. So if you don't understand, really happy to try to help..

[Papa-lf]

zman.. the only question that is dumb, is the one you don't' ask.. So if you don't understand, really happy to try to help..

Mark, I think you made a friend - hopefully me too...

(700 new pixels sitting in the box from Ray - just itching to fire em up)...... LOL