Re: New project...PCI based servo control board

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

Ok, got an idea!
Thank you, Jon,  for a great explanation.
Regards, Alex
----- Original Message -----
From: Jon Elson <elson-at-pico-systems.com>
To: Multiple recipients of list <emc-at-nist.gov>
Sent: Tuesday, April 01, 2003 1:21 PM
Subject: Re: New project...PCI based servo control board


>
>
>
> alex wrote:
>
> >Folks!
> >I know nothing of FPGA.
> >But why , if we are talking of ISA bus, not to use a standart C to write
and
> >compile an application?
> >
> The whole problem, at the beginning, is that software generated step
pulses
> are not regular enough, or can not be ramped up and down in rate smoothly
> enough, for some stepper motor applications.  Replacing a x00 MHz Pentium
> with a PIC is not going to solve this problem.  For instance, I have a
> product that
> produces step pulses up to 300,000 per second, per axis, with a timing
> resolution
> of 100 nS.  So, even at 300K steps/sec, the granularity to the next
> faster or slower
> speed is only 3.3%.  (The FPGA is loafing at this rate, if you needed
> more, the
> clock could be turned up.)
>
> Depending on the algorithm, software generated step pulses may have
> granularity
> of 25% or so at these rates.
>
> It can get worse if you want to have encoder feedback of actual
> position, too.
>
> Jon
>
> >
> >
> >
>
>