Re: [LCtalk] buffer delay ?

[Fokko van Duin]

At 17:46 +0000 09-02-2005, Gideon Kiers wrote:
> Hi there,
>
> When i send a dmx value from the lighting desk through the lanbox 
> into max, there seems to be a very constant delay of a couple of 
> miliseconds.
> Sending various dmx values after each other come in well timed and 
> in order, but everything just a bit later.
> Is this delay something that is presettable on the lanbox ?

No, this delay is due to the way how DMX works. DMX (Digital 
MultipleXing) packs up to 512 bytes (channels) in one packet, and 
sends it out with a speed of 250K bits/sec over the cable. It means 
it takes at least 23mS before it's complete received (when the 
desk/controller has fast DMX, see also 
<http://www.lanbox.com/support/dmx-timing-v203.html>).

But this not all, as the LanBox processes all data every 50mS, it 
delays the packet an average of 25mS. And lastly there is Ethernet 
which adds another several (5-10) milliseconds.


--
Fokko van Duin,                     Creators of the LanBox-LC
CDS advanced technology bv,         DMX lighting controller.
http://www.cds.nl/                  http://www.lanbox.com/

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