Re: FPGA for PCI based servo control board

[Robin Szemeti <robin-at-rszemeti.demon.co.uk>]

On Friday 04 April 2003 15:19, ERIC KELLER wrote:
> 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

err ... almost any cheap motherboard? ...  the micro-itx/atx format boards 
are more expensive than a 'standard' motherboard ... plus cases are more 
expensive than standard cases etc etc ...  it would be a good choice IFF 
space was a problem ... even in my rather cramped shed I could find the room 
for a standard PC case, which will work out cheaper.

The elan is just a PC motherboard, except it only has one PCI slot, and its 
more expensive than it need be. if you really intend to go down this route, 
could I suggest www.openbrick.org have already done the hard work for you.

Personaly for that sort of money I'll buy a 'real' PC,  more performance for 
your money, until the space in the shed is really tight.

Don't get me wrong, if someone can produce a PCI card that does handle the 
realtime stuff for reasonable money, I'll be very interested.  the idea of 
the hard sums being done by hardware, passed out on ethernet to a breakout 
board, where a few registers convert raw ethernet packets into pulses and 
control logic sounds an interesting one,  without an IP stack to worry about 
it shouldn;t be too hard.  If you have an ehernet port on the 'PCI control 
card' and use that to link the 'expansion IO' board that sounds quite a cute 
idea. No ethernet drivers to wroory about as it is talked to directly by the 
PCI card hardware ...

I'll watch with interest ...

-- 
Robin Szemeti