Re: FPGA for PCI based servo control board

["ERIC KELLER" <eekeller-at-psu.edu>]

Using a standard nic for real time communication has been done a number of times
now.  Look at RTnet:
http://www.rts.uni-hannover.de/rtnet/

I don't know where you are going to get a cheaper embedded computer than a VIA
elan board

http://www.newegg.com/app/Showimage.asp?image=13-180-025-04.JPG/13-180-025-03.JPG/13-180-025-01.JPG/13-180-025-02.JPG

Eric

 
> >  If the Linux
> >drivers are indeed not accessible to real-time tasks,
> >then any ethernet solution will require writing a
> >real-time compatible NIC driver for every brand of
> >NIC.  On the other hand, if real-time tasks can
> >use the existing Linux NIC drivers with a clean
> >raw packet interface, ethernet looks very good!
> >
> No way.  It might be possible to extract a common section of the
> protocol stack, and use that as the basis for the RT code.  But, it would
> almost always require hand massaging, I'm afraid.  Once you go
> outside the RT code for anything, you are, BY DEFINITION, no
> longer real-time.  That code could lose control due to a higher priority
> task, and the message would not get there in time.
> 
> Jon
> 
> 
> 
>