Re: stepper pulse rate idea

["alex" <telecomt-at-tht.net>]

----- Original Message -----
From: Jon Elson <elson-at-pico-systems.com>
To: Multiple recipients of list <emc-at-nist.gov>
Sent: Friday, March 14, 2003 12:56 PM
Subject: Re: stepper pulse rate idea


>
>
>
> alex wrote:
>
> >I think that the best way around it is to network EMC postprocessor to
> >DOS module which would work in real time, with encoder feedback.
> >If loop length limit for RT LINUX is 1ms, for DOS it can be easy .1 ms,
> >or less. Heck, it can be done in assembler even!
> >Technically it is quite easy to do as well - just requires recompiling
some
> >modules for DOS.
> >
> >
> Stepper timing in software on EMC is already done at somewhere between
> 50 uS and
> 16 uS, faster if your CPU can handle the interrupts.  So, there is NO
> advantage if
> adding another CPU and CPU-CPU communications overhead to get faster
> interrupts.
>
> 1 mS is adequate for servo motion control systems, there's no NEED to go
> faster in
> most systems.  That's why we get excellent performance on 100 MHz
> Pentium classic
> CPUs.
Yet in one of the previous posts you mentioned that commercial system
can work at 10 - 60 khz sampling rates. I presume that the higher the rate,
the better performance of the machine.
DOS can do it.
Alex.
>
> Jon
>
>