Re: [CAD_CAM_EDM_DRO] Re: Re: Windows Real-time

Ballendo:

Yeah, I know, I though the same thing at first. But when you think about
it, the pulse only has to be a microsecond long, so when I set the pulse, I
just wait a microsecond to turn it off again. Now say I want 6000hz,
well, lets just set the time to next pulse to 166.6667uS after the pulse I
just made. So on the next interrupt 122uS
has passed, since I know that the next interrupt will be after the 166uS I'm
set for, I just hang on to the interrupt for anoth 42.6667uS and then turn
on the pulse and then turn it off again a microsecond later, then release
the interrupt. I won't need it again for another 166uS. or a repeat of the
above proceedure. This is very accurate
so that I can actually pulse from 1hz to 8192 on my 500mhz computer. The
pulse with can be accurate to the nanosecond for the most part. 122uS
granularity only sounds like a problem, it really isn't one at all.
My stepper motors have never sounded as smooth,
and have doubled in speed capacity. As long as a higher
interrupt does not occur, its better than the emc spec's I've read. And the
higher interrupts do not occur unless you start to do some pretty heavy
stuff. I know its not
a perfect solution, but it does seem to work quite well.

Art

----- Original Message -----
From: <ballendo@...>
To: <CAD_CAM_EDM_DRO@egroups.com>
Sent: Tuesday, November 28, 2000 2:53 PM
Subject: [CAD_CAM_EDM_DRO] Re: Re: Windows Real-time


> Art wrote:
> <snip>If the pulse should occur within the 122 us granularity I wait
> until then to pulse the port. All masking, pulsing,status checks and
> control outputs are done at the same time,<s>
>
> Art,
>
> What happens when the "ideal" pulse output occurs outside of your
> 122us granularity? Yes, I think you already answered this above; I
> just want clarification.
>
> So is it "every 8196th of a second, I either "DO" or "DO NOT" pulse a
> given axis(set/clear the port pin) or are you using the sub-timing of
> the rdtsc to output pulses at a "more exact" time?
>
> Since a pulse involves BOTH a set AND a clear, is the pulse rate
> max'd at 4048hz? Else how do you clear the bit?
>
> Thank you in advance.
>
> Ballendo
>
>
>
>
>
> Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
discussion of shop built systems, for CAD, CAM, EDM, and DRO.
>
> Addresses:
> Post message: CAD_CAM_EDM_DRO@egroups.com
> Subscribe: CAD_CAM_EDM_DRO-subscribe@egroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@egroups.com
> List owner: CAD_CAM_EDM_DRO-owner@egroups.com, wanliker@...
> Moderator: jmelson@... [Moderator]
> URL to this page: http://www.egroups.com/group/CAD_CAM_EDM_DRO
> FAQ: http://www.ktmarketing.com/faq.html
> bill,
> List Manager
>