Re: regarding future plans for EMC

[John Sheahan <jrsheahan-at-optushome.com.au>]

On Tue, Feb 05, 2002 at 05:15:14PM -0500, Fred Herenius wrote:

just a couple of points that touched my fancy
> Pete Cook> ideas.
> If this is indeed the case, is there any planned date for a feature-freeze?

is a lot gained by the magic transition to 1.0 ?


> 
> Homebrew hardware:
> Another reason for going the above route of doing it module-wise is as
> a proof that the modularity is actually working. And if the modularity
> is actually working you can start thinking about moving modules (in whole
> or in part) to a platform different than your main pc/alpha/whatever.

I'm not sure I agree here. 
I don't run emc on my main machines, but on a junky old pile of scrap 
in the workshop.   which is heaps cheaper than the alternatives you 
suggest.  even new pc's tend to be very cost competitive with
dedicated embedded controller boards.   economies of scale..

obviously realtime response can be a killer however.
> 
> For example, you could make a board to control the rotational speed
> of your favorite spindle. Instead of using the PC to generate the pulses,
> you could use a lowly microcontroller to do that for you, and to accept
> high-level commands from the PC through a (serial) bus of your
> preferred flavour. At home I use I2C for this, but in an industrial
> environment you could use something else.
> 
> If that concept works for EMCIO, then why not for EMCMOT?

makes sense. but not serially please. look at the current 'standard
platform' documents. ethernet or usb seems the only reasonable choice 
here, (if serial means rs232)

> 
> And on the subject of homebrew hardware, how about trying to get a
> repository with plans for homebrew controllers. Schematics for those who
> like to wirewrap/breadboard/etc. Postscript or other plot-files for those
> who like to etch their own. I know there are a plenty of schematics on the
> net, but for the beginning EMC enthusiast it might be much easier if there is
> a clearly defined list of homebrew designs to choose from that are know to
> work with EMC, complete with description on how to get it up and running.
> 

I can provide a web page for this and contribute some stuff if there
is general interest.

> 
> > Might there be more involvement if the OS were something other than Linux? I
> > am thinking more of a DOS or FreeDos environment.
> Install Yoda style "DOS -> anger -> hate -> suffering" quote here.
> Why would you want to do that? 

exactly. been threr done that, not again please.  
and a dedicated computer is cheap compared to the stuff its
controlling.

> 
> > Another approach would to move EMC off the main CPU and onto a PCI or ISA
> > type card - yes this would require the design of special hardware, but it
> > would make the OS of less importance. 
> As said, I'm all for that. Well, at least for EMCMOT and EMCIO. The GUI and
> EMCTASK are just fine on the PC. Oh one other thing, I wouldn't make a
> PCI or ISA card. I'd just make a standalone board and let it accept high-level
> commands from EMCTASK (on the PC) over a serial link. As a bonus you have less
> chance of blowing up your slots while developing the boards ;-)
> 

ISA has reached the end of its life and should be quietly buried.
Sure its easy to design an isa card. but pci is not a lot harder.
A remote box , say with ethernet and a socket interface makes sense.
Rabbits and other things can support ethernet with just a couple of
chips.

> - Just thought I'd ask, anyone else on this list into hobbying with
>   FPGAs, CPLDs, DSPs, that sort of thing?

not dsp.  
john

> - Are you still reading this?