Re: Signal gen Interface

Jeff / Ron,

I am on the same page you two are. I have been looking at something
like a PC104 single board computer which has both serial and parallel
ports. Do the g-code stuff, trajectory planning and what ever else on
the PC, when gets to the point of being ready to make a move, send a
simple move command to the SBC which would calculate the number of
steps, create the pulses and maybe even monitor encoders for position
feedback. If you were thinking about EMC, that would be like putting
the emcio and emcmot functions on the SBC and keeping the remainder of
the functions on the PC.

In my opinion EMC is still way two complicated for the average HSM to
set up and make use of. EMC is a nice product that does a lot, maybe
two much for the average home shop, but it requires a great deal ok
knowledge that I am not sure most HSM's posses.

Using something like a small single board computer should allow rather
easy development of an open architecture pulse generator that could
work with both steppers and servos, function in either open or closed
loop environments and overcome many of the current limitations seen
with Windows and real time applicatons. I had plans to write a CNC
program for the SimpleStep controllers, but I feel that is to
limiting. I plan on starting to explore the above described solution
very soon. I might be a little nieve here, but I don't see any reason
why this type of solution can't work. Sure, the cost will be more
than $20.00 per axis for the "pulse generator" but then if it wil work
with a single board computer for the pulse generator, then it would
also work with an old PC for the pulse generator. I think the key is
making sure that the processor only has a very limited number of
things it must do. You should be able to get a reasonable pulse
stream out of almost any processor if the only thing it has to do is
generate the pulses and maybe monitor the encoders for position.

John Guenther

--- In CAD_CAM_EDM_DRO@egroups.com, Jeff Barlow <jeff@b...> wrote:
> Ron,
>
> I'm not sure any two of us are on the same page here! I think you
and I
> have at roughly similar ideas, though.
>
> With this many ideas flying around we're bound to stumble over a few
> good ones.
>
> Jeff
>
>
> On Thu, 07 Dec 2000 22:58:49 -0500, you wrote:
>
> >I am not sure we are all talking about the same kind of box here.
In my
> >view there are no interrupts between the box and the PC. My view is
like
> >the command set of the Simple Step or Pic Servo, or even
INDEXER.LPT.
> >
> >The PC would calculate the next coordinate, and the box would
handle all
> >the timing, sending back some kind of ACK when that move had
occurred,
> >and ready for the next move. The moves can all be in just step
units,
> >let the PC figure out how many steps to move and do the inches or
MM
> >stuff.
> >
> >This discussion of frequency generators and interrupts is still in
the
> >domain of someting that requires a device driver. I think a
parrallel
> >port or serial- or even a USB would be fine. I know USB has some
timing
> >issues, but remember Im thinking that the commnads to the box will
be
> >for entire moves not for single steps.
> >
> >Are we all on the same page here?
> >
> >ron ginger