Re: Help

[Fred Proctor <frederick.proctor-at-nist.gov>]

Dimuthu Seneviratne wrote:

> I have undertaken to retrofit an old 2 axis CNC lathe. We have got down a
> Servo To Go Model 2 card to be used as the controller and want to use EMC
> software. There are few things that I want to clarify from you.
> 
> 1. Is EMC software compatible with Servo To Go Model 2 ? If it is
> compatible can I use the software as it is - without any    modifications?

Yes. The motion controller for this is "stg2mod.o".

> 2. In addition to the digital outputs provided by EMC, I want to have
> several more outputs to control things like spindle gear box
>   (4 relays), tool changer, chuck open/close etc. Is this possible?

Yes. I'd do this using the parallel port. "Possible" in this case means
you need to write your own IO controller. The one that ships with the
EMC is set up for Bridgeport knee mill I/O, which doesn't have a spindle
gear box, tool changer, chuck open/close, etc. There are several ways to
write an I/O controller. You can do this in C++ or Tcl/Tk, using the
examples in the emc/src/emcio directory. I would do this using Tcl/Tk
since it's probably the fastest. Look at the tkio.tcl example in this
directory.

> 3. This machine has a hydraulically operated tool changer, which is
> controlled using a single relay. It can carry six tools and with    each
> activation of the relay moves to the next position. It can       travel only
> in one direction  - so for example if it needs to    change from tool 2 to
> tool 1, it has to make a full circle. Can I
>    incorporate this sort of functionality in to EMC?

Same answer as for (2), since spindle, coolant, tool changer, etc. all
go through the same communication channel. If you can't use the parallel
port (too few bits, etc.) you can use any I/O card you want. The Tcl/Tk
script calls inb/outb to write to the PC I/O address space, so if you
know the I/O address map for your board, you can just put these into
your script.

--Fred