Comment by blhack | Hacker News Reader

Comment by blhack | Hacker News Reader

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Really cool. It's always interesting to see how this stuff works on the back end.

An interesting thing on the tech side, is that almost all of the lighting and effects in that building are probably controlled via a relatively-ancient protocol called either: DMX or Artnet

https://en.wikipedia.org/wiki/Art-Net

https://en.wikipedia.org/wiki/DMX512

Come from a software/networking background, this was really interesting to me because the address-space is so small! 512 channels per "universe", and most control boards supper only a few "universes".

Part of my life (when I'm not writing computer software) involves shooting fire effects at music festivals, so I have [luckily] gotten really interesting exposure to a small part of the tech that makes stage/theater productions happen.

Modern consoles can control a lot of universes these days. A grandMA2 full-size can run 256 universes corresponding to 65k parameters in one session, a Whole Hog 4 is basically unlimited.

When you're running that many fixtures (big events like Olympics ceremonies, Eurovision et c) you're usually bumping up against the limits of the operator and tend to run multiple sessions with multiple operators so they can program scenese in parallell.

Wow, really cool! Grand Ma is definitely beyond the realm of what we're doing (we use chamsys for lighting control).

I wonder what it would take networking-gear wise to deliver the same sort of data to the same number of hosts. My naive answer is "not much".

DMX512 runs at 250 kbit/s, so yeah, "not a lot". I've usually seen standard rackmount gigabit switches in installations, when I was involved in touring audio it was usually fanless consumer switches (think 8-port netgears), but these weren't for ethernet snakes.

In terms of data, audio multicores over ethernet and video content distribution/playout massively dwarfs the bandwidth that lighting uses. But when it goes down, everyone notices.

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