Hi all,
This topic comes up every now and then – sorry if this has been answered
before.
Has anybody had any experience (good or bad) with real-time “extensions” to
NT? A while back, our company had investigated products such as
HyperKernel, but ended up not using them because the scope of the projects
we were involved with did not truly require “real-time” performance. We
currently stuff National Instruments’ data acquisition & control cards in a
PC, and write custom software to interface to them. Not exactly
“real-time” in any sense of the word, but adequate up to now beacuse the
control requirements were not stringent.
Now the question of “real-time” has come up again here (more stringent PID
control requirements), and although I’m a firm believer that “real-time” is
not possible under NT (or W2K, or any other general-purpose OS), I’m
charged with re-investigating the possibility of using such extensions (or
finding other solutions) “Other people do real-time control in Windows” I
hear from higher ups here – but I’m not buying it – not yet anyway.
All the information I’ve read suggests that interrupt latency is not
predictable, and built-in timer performance is not predictable. So without
a predictable stable time-base, stable control (in my opinion) cannot be
assured. I must admit that I’m biased toward using devices that have their
own microcontrollers (and dedicated software/firmware) on them, but
nonetheless, I’d like to hear from anyone who’s had any experience with the
NT “extensions” or similar solutions.
Thanks in advance for any thoughts or suggestions.
-bill
Bill Christie
Link Engineering Company
www.linkeng.com