Re: FPGA for PCI based servo control board

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

On Thursday 03 April 2003 19:15, alex wrote:
> Why not to use a SBC/cheap computer, networked to main EMC machine?
> It already comes with ISA bus. FPGA board can be plugged in into it.
> Then all the real time functionallity from Linux can be unloaded into it as
> well,

Thats a good idea! ... and offload all the 'hard realtime' stuff to that 
outboard box .. hmmm that has a lot of very positive benefits. I'd suggest 
that the 'cheap computer' is a far better way to go than the 'SBC' as a 2nd 
user PC can be picked up for a few dollars, yet even a basic industrial SBC 
is lots more ... the PC would also be already in an enclosure, with a 
powersupply etc, so overall that would seem to be the best choice.

I guess it would be easiest if we ran a linux kernel on it rather than 
anything else, network it to the main EMC machine and just send motion 
commands to it.  It would probably have to run a realtime linux though ... 

Another thought I had while thinking about this is that PC's are getting 
faster and faster ,, there might even be enough processor power in the PC to 
provide some signals for stepper motors *without* the need for a custom PCI 
or ISA card, sure would make it simpler for the hobby users who don;t need 
blistering step rates.

I don't know what you'd call such a thing though .. Extended Machine 
Controller ... that runs nicely .. EMC hmmm ...  I'm sure I've heard that 
name before somewhere .... 

must go ... I'm involved in a working party to produce a design for providing 
a simple form of motion assistance for heavy loads .. we're at a crucial 
stage now .. one of the team has had a breakthrough and discovered that a 
large circular shaped object can be persuaded to roll very easily ...  next 
up we're going to try a circular flat disc to see if that works just as well 
.. 

-- 
Robin Szemeti