Re: Automatic tool changing ?

[JohnDRoc-at-aol.com]

I spoke to Fred Proctor about this when I went up to NIST to visit - I think 
he also spoke to Ray Henry about it as well.  We discussed the possibility of 
using a Soft-PLC with a separate I/O board to handle the non-realtime I/O.  
This would allow for additional and more flexible I/O.  One could probably 
devise a memory share between the PLC and Task, similar to the one between 
Emcmot and Task (I think).  Right now I'm working on the retro-fit of a 
Milltronics PartnerVII, with a defunct Centurion IV control and a 20 tool 
changer.  Originally they used an Acroloop 1000 servo-I/O board and Omron PLC 
to run the Tool Change functions.  I don't know much about the tool change 
(I'm still trying to get 1 axis - any axis - to work), but that Acroloop may 
hold some potential.  I looked it up online, and it's either ISA or 
standalone, and it has some PLC functionality built in.  I don't know how 
much it costs, but if it isn't too bad (which is relative, I know) I would 
think that it would be a matter of programming a standard tool change that 
would be split by Task, which would in turn send a Pause to Emcmot and a Tool 
change to the Acroloop, then when it's completed, it would send a Continue 
back to Task.  I haven't been able to find much in the way of a Soft PLC.  
There is a relatively new project called "Puffin" at www.linuxplc.org, but it 
is still in the early stages of development (they have a mail list, too).  I 
would enjoy hearing other suggestions, or if anyone knows about the ACR1000 
board.

-John