Recent content by jfitzpat

I think this sums up nicely what I was trying to say before. Safety generally involves a multi-part system with some redundancy. A communication protocol is just one part and, in of itself, may or may not matter. -jjf

Ship, I'm not going to go through your two long posts point by point, but the materials in the light source are statistically insignificant when compared to the amounts of mercury, HCs, and NO being released in the production of the power. Remember, in CA we not only burn a ton of coal, a...

The most likely form of error is a line bit error. Without a checksum or CRC, how does the receiver know to discard the command instead of executing a corrupt one? Read my post above, most the approaches that I am aware of do not use DMX this way. Much as MSC uses a SYSEX message to embed...

I think that they are really two different things. Tons of big fireworks shows are pre-programmed to tape each year. In the highest tech ones, the very precise firing control is even required. The pre-programming gives a very tight, well coordinated firing - but it does not negate the need...

I would readily agree with the comment above that rigging/flying involves serious safety concerns and should not be undertaken lightly. I would also agree with the statements that DMX is a terrible native format for safety related control. Frankly, I've always thought that the complete lack...

I thought they had given up on that. I remember hearing about a screaming match at a meeting a year or so ago. But I grumble about paying a bloated fee for a copy of a standard, so you can imagine how I would feel about a protocol license fee... ;) -jjf

Wow, lot's of good comments, etc. Forgive me if I miss some: jmabray: Here to stay? Almost certainly, as is DMX-512A, but a successful protocol? Remains to be seen. Understand, I've been involved with standards bodies many times over many years. Some amazing effort went into some USB...

Yes, but at slower rates. The old coax Ts and terminators would not really work for 100mbit or 1G ether. Also, remember why 10BaseT became popular in the first place. A coax multidrop for ethernet had pretty much the same cost and connectivity problems as DMX-512. Synchronous networks run...

FWIW, Artistic License placed ArtNet in the public domain without restriction or royalty. There is a downside that the protocol document is maintained by a private entity, but that could be rectified. It is actually getting pretty widely adopted. We'll output it, and a lot of visualizers...

Makes sense, balanced shield to earth ground on both ends - but by strapping 1 inside the equipment. The mic cables I pulled out of the milk crate here had body<>body conductivity, but who knows how old they are or where they came from. My one note would be, don't be fooled by plastic XLR...

Forgive my ignorance. I thought that current AES best practices was to use a balanced shield connected to earth ground, not audio ground, at both ends. -jjf

If I didn't make it clear above, the standards are two very different things. RDM (Remote Device Management) is an attempt to standardize something that High End has already demonstrated. Namely, using the bi-directional capability of RS-485 to remotely obtain information about a DMX and...

RDM seems like a sensible, incremental improvement that fits reasonably well in existing wiring and infrastructure. ACN seems like a huge, rather vague, pipedream that seeks to solve a problem that I am not 100% sure even exists (I haven't lost much sleep over, say, multi-controller, multi...

JD is correct, shielding does not resolve several noise sources. Ideally, you want twisted pair (so noise is distributed evenly) and shielding braid and foil. However, in this case there is a bigger problem still - A lot of existing DMX devices bind chassis to earth ground, so with a mic...

Exactly! However, Len's point also applies - weight, both hanging and trucking, and power are never in endless supply. -jjf