On Thu, 31 May 2001 11:07:13 +0200, Roland <rv@ronetech.com> wrote:
> Yes
> 
> Actually with DOSX we run at 40000 hardware interrups per seconds.
> 
> I think i will never go as fast on Windows.
> 

Depends on what the PC-Spec is and what else you are running.

I avoid Windows for real-time applications if at all possible, but my main reason is uptime of the OS :>

> So i need to make some harware (buffer) to help Windows.
> 
> But how much ?

Not knowing exactly how your hardware and software works limits suggestions that can be made.

I would not suggest buffering the interrupts, but dealing with the interrupts
on the external controller. Passing only high level commands to and from the external
controller.

Does the PC control the stepper moters of the CNC machine directly or is there a controller in the CNC already? or do you have an ISA/PCI card sitting in the PC?

A small external 16bit processor board would probably cost between £20 to £100
(pounds) depending on how complex the board is (not taking into acount
development cost of the board and associated software). But this is a big guess as I
don't know enough about your setup.

If you already have a ISA/PCI card then it may be more sensible to enhance this card rather then add an additional external controller.

> 
> The faster i can go on Windows, the cheaper and simpler is the hardware associated with it.
> 

Yes. However you may find adding an external controller is cheaper then trying to get your windows program to run fast enough.

As you probably already know if your control program is not fast enough you will probably lose cutting accuracy.

Hopefully my suggestions have helped you, but as you can see there is a limit to what I can suggest based on the information you have posted.

Regards
Damian

> Thanks
> 
> Roland
> 
> Damian Dixon a écrit :
> 
> > I would suggest looking at spliting up your system so that the realtime element of the CNC controller runs on a small embedded board.
> >
> > You will then only need to write a simple windows program to send commands to the
> > CNC controller to instruct it how to cut (start position, stop position, speed, depth
> > and path). You could probably get away with using RS232 or the printer port for
> > the comm's.
> >
> > Regards,
> > Damian
> >
> > On Mon, 28 May 2001 22:15:28 GMT, Mark Evans <mevans@zyvex.com> wrote:
> > >
> > > My advice is the following.  If you want true real-time performance with Windows compatibility, then you need a Windows API emulator that runs on a real-time kernel.  On-time sells exactly
> > > that.
> > >
> > >               http://www.on-time.com/
> > >
> > > Personally I would never bother with Windows for hard real-time requirements.
> > >
> > > You might also consider the WINE project with Real-Time Linux, but I am told that RT Linux is much less mature (more buggy) than Linux per se.
> > >
> > > I'm no expert on DOSX but presumably if it runs under DOSX then it will run under Windows emulation.
> > >
> > > Mark
> > >
> > >
> > >
> > > On Sat, 26 May 2001 01:48:30 +0200, NancyEtRoland <nancyetroland@free.fr> wrote:
> > > > first i esitate to expose my problem here as it is not specificaly DM C++.
> > > >
> > > > but i would like it to have a DM C++ based solution..
> > > >
> > > > More informations:
> > > >
> > > > a PC based little cnc machine:
> > > >
> > > > - must run a real time softwear,
> > > > - must run a "'evoluted" OS because it is plugged on a LAN with other pc's,
> > > > a web cam is plugged on it, it is plugged on Internet  for remote mantenance
> > > > (Symantec pcAnywhere), etc..
> > > >
> > > > well i don't feel like making all those drivers on MS-DOS..
> > > >
> > > > The actual solution is:
> > > >
> > > > A windows CAD/CAM program on the cnc and on the pc networked with it,
> > > > a DOSX program only on the cnc, for driving the cnc itself on real time mode
> > > > on pure dos.
> > > >
> > >
> > >
>