Can the XP Operating System be used as a real-time controller?



Jeff A
07-10-2005, 12:56 AM
I would like to continue building the CNC (Computer Numerical Control)
software - but would love to run it on Windows XP. Everything I read about
CNC says that DOS is a better platform because it runs no background services
and therefore doesn't interrupt the sequence of events.

Is there a way from a programmer's perspective to turn off certain services
on XP and emulate a more real-time environment?

I appreciate all feedback on this question...

Bob I
07-10-2005, 12:56 AM
That IS a scary thought! Real time control here is by using PLC's and
then use the Windows box to update parameters on them. The Windows box
is the GUI for the PLC doing the actual control.

Jeff A wrote:

> I would like to continue building the CNC (Computer Numerical Control)
> software - but would love to run it on Windows XP. Everything I read about
> CNC says that DOS is a better platform because it runs no background services
> and therefore doesn't interrupt the sequence of events.
>
> Is there a way from a programmer's perspective to turn off certain services
> on XP and emulate a more real-time environment?
>
> I appreciate all feedback on this question...
>

DanS
07-10-2005, 12:56 AM
=?Utf-8?B?SmVmZiBB?= <Jeff A@discussions.microsoft.com> wrote in
news:B555D412-CA7F-4633-B55B-9372EBABB7D0@microsoft.com:

> I would like to continue building the CNC (Computer Numerical Control)
> software - but would love to run it on Windows XP. Everything I read
> about CNC says that DOS is a better platform because it runs no
> background services and therefore doesn't interrupt the sequence of
> events.
>
> Is there a way from a programmer's perspective to turn off certain
> services on XP and emulate a more real-time environment?
>
> I appreciate all feedback on this question...
>

XP would really NOT be the platform to do this kind of thing on. Of course
this also depends on what you are controlling. A powerful, large CNC
machining center would REALLY not be a good idea.

If you really insisted on doing the actual machine control with a Windows
box, I would most likely use Win98, which has a LOT less overhead. Even
start out with something like this, http://www.etek.chalmers.se/
~e8gus/nano98/ , which is a SUPER small install of Win98. Of course, it
couldn't be that slim as more of the Windows system DLL's would probably be
needed.

It would also require, IMO, the use of several threads, with the ones doing
the control set to be high priority, but maybe not realtime. In a testing
utility I wrote, in order to get better performance, I had a button for
'Set Realtime Thread Priority'.....mistake, after pressing that, even the
mouse wouldn't move.

If you want to play around anyway with XP, take a look at this,
http://www.nliteos.com/nlite.html , nLite is similar to 98Lite.

Regards,

DanS

Anando [MS-MVP]
07-10-2005, 12:57 AM
Hi Jeff,

I dont have much of an idea about CNCs, but you can change the way windows allocates resources to
backgound processes and running programs. This can be done by going to the advanced system
properties (Windows key+Break), flip to the advanced tab and click on performance. Once again flip
to the advanced tab and here you can select your options. Hope this helps.

--

Anando
Microsoft MVP- Windows Shell/User
http://www.microsoft.com/mvp
http://www.mvps.org

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"Jeff A" <Jeff A@discussions.microsoft.com> wrote in message
news:B555D412-CA7F-4633-B55B-9372EBABB7D0@microsoft.com...
>I would like to continue building the CNC (Computer Numerical Control)
> software - but would love to run it on Windows XP. Everything I read about
> CNC says that DOS is a better platform because it runs no background services
> and therefore doesn't interrupt the sequence of events.
>
> Is there a way from a programmer's perspective to turn off certain services
> on XP and emulate a more real-time environment?
>
> I appreciate all feedback on this question...
>

John
07-10-2005, 12:57 AM
Jeff A wrote:
> I would like to continue building the CNC (Computer Numerical Control)
> software - but would love to run it on Windows XP. Everything I read about
> CNC says that DOS is a better platform because it runs no background services
> and therefore doesn't interrupt the sequence of events.
>
> Is there a way from a programmer's perspective to turn off certain services
> on XP and emulate a more real-time environment?
>
> I appreciate all feedback on this question...
>

If you are talking about the machine tool controller's software then
you must be joking. When XP takes a hissy fit and wrecks your $500K+
machine tool who you gonna blame - Micros~1 ??

If you are talking about creating CAM software then DOS would be my
last choice. I wrote CAM software in the late 80's & early 90's that ran
under DOS. It was quite capable then and could still be used today. But
if you expect to sell your work in today's market go with XP or a UNIX
flavor, DOS is a dead end.

If on the other hand you are talking about DNC (direct numerical
control) then its really just a communications network and in the vast
majority of machine shops any OS will do. There are DNC packages
currently on the market that run in XP and can trickle feed a really old
machine or do decorative X,Y,Z work, no canned cycles, no circle
interpolation. You know the type - where the program is too large to fit
into the machine tool's controller. I can tell you from experience that
it works running under XP and computer response time is not a problem.

John


Can the XP Operating System be used as a real-time controller?