Re: DMX Branch Lines

On Apr 26, 2:46=A0pm, Torrance Bell
<starlite...@[EMAIL PROTECTED]
> wrote:
> > RS485 is unlikely to go 4000' for Baud rates higher than 19200. DMX is
> > 250kBaud and both ends of a DMX line should be terminated. This
> > prevents reflections from the unterminated end interfering with the
> > outgoing data. It is not generally recognised that the source end
> > should be terminated, but this is im****tant and should be internal to
> > the master device. Measuring with a meter across the signal pins of
the
> > source when the source is unpowered will tell you if it is correctly
> > terminated.
>
> > For all the information you never thought you'ld need about RS485
> > networks go here:
>
> >http://www.bb-elec.com/technical_library.asp
>
> > and download the first paper "Rs-422/485 Application Note".
>
> Heh, I never would expect it to go that far anyways.
>
> Torrance- Hide quoted text -
>
> - Show quoted text -

In case you hadn't noticed DMX is not "just" RS485.

Consult www.esta.org for the DMX specs. Many variations work, but only
under limited conditions.

RickR