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[rtl] Newbie Stuff
Hi everyone,
Just started looking into RT systems for our new interferometric
telescope array on Mount Wilson, the CHARA Array. This consists of
five one meter telescopes in a Y shaped array, connected optically
(like an optical VLA). There are many RT systems involved. Besides
the telescopes themselves there will be delay line carts, fringe
tracking systems, tip/tilt systems and so on. All of these need to be
synced together.
I looked at commercial systems (VxWorks etc) but as we are a
University project the budget is tight, besides the whole Linux thing
appeals to me. We've been using Linux for some years now and I have
been playing with RT-Linux under the 2.0.33 kernel. After only a
short time, I'm very impressed with the simplicity and ease of use.
My problem is, we will have many independent CPUs running various RT
processes, and they all need to be synced together somehow. Using the
simple scheduler that comes with RT-Linux is no good as it does not
use an external clock signal. My plan right now is to use some
simple electronics and the printer ports on the the machines to get
an external interrupt into all the machines, based of course on the
same clock signal. Rather than write my own scheduler is it stupid to
think I can modify the standard one to use an external interrupt
instead of the internal clock? Is there a more obvious way of doing
this?
If people are interested I'd be happy to let them know how the
project developes, we've only just started out on the mountain and it
will be some years in the making. Our web site is
http://www.chara.gsu.edu
for those who would like to know more.
Theo ten Brummelaar
--- [rtl] ---
For more information on Real-Time Linux see:
http://rtlinux.cs.nmt.edu/