Re: Commercial software

> From: "Jon Pritchard" <jpritchard@...>
>
> To Matt and List: I'm new here....guilty as charged!

First, let me apologize for the flip attitude I took with you in responding
to your initial post. Its just that we've been having a pretty long
discussion here regarding various control programs and the EMC software
sometimes to the tune of 10+ posts/day and your question seemed hilarious to
me at 1am when I read it. I'm really not like that at all ...

> 1. Can a machine control "soft" PLC be incorporated with EMC to run
> other machine control such as auto toolchangers etc? Or does EMC have
> this built in?

One of the first EMC installations was on a K&T mill that had a tool changer
and a multispeed gearbox. See

http://isd.cme.nist.gov/projects/emc/testbeds.html

far a picture of this. This project was a few years ago before the software
was ported to Linux. The PLC portion of the EMC code has the facilities to do
this type of control, but there isn't an easy to use "ladder logic" type
programming front end that can be used to set it up. The short answer to your
question is that the capability is built in, but some custom programming will
be required to implement a solution specific to your machine. There is
another fellow in Kentucky who has a similar project in mind. I'd like to see
more details of how the electrical/mechanical interface works on your machine
to determine the number of I/o points needed, whether the tool changer's
operation requires tight tolerances in the timing of its operation, etc. This
is really a question for Fred Proctor at NIST and I'll ask him about this
next time I talk to him, probably today.

> 2. Is it possible to put together some of the pretty screens for
> talking to EMC sort of like one sees on commercial CNC? Whats the
> programming language that would typically be used to do this?

Pretty screens we've got! See Jon Elson's EMC page

http://ascc.artsci.wustl.edu/~jmelson/EMC.html

for a nice screenshot of the XEMC user interface. This program runs (as you
might guess) under X Windows which comes with Linux. There is also a Java
based interface to the EMC. It caused a lot of problems in the beginning, but
is now said to be fixed. I haven't tried to use the official version since
then, but I did write a prototype Java user interface that you can see at:

http://www.erols.com/mshaver/emcgui.htm

There's no documentation, but go there with either Netscape or IE with Java
enabled. After it comes up press the Power button, then the Reset button.
After that, highlight the four axis position display blocks, one at a time,
on the left hand side of the screen and press the Home button near the top
right for each one to home each axis. After that you can change the jog
increment from High to any of the incremental values in the drop down menu
and use the + and - keys on either side of the home button to jog the
highlighted axis. Play around with the rest of it and tell me what you think
(especially note the background color change when you press Run and Pause).
This is only a "dummy" program for simulation, and hasn't been integrated
into the EMC, although there is an existing class that would allow it to be.
I did this a while back before there was an X interface as a way to show
people what I thought a cnc user interface should look like. It's also my
very first (and perhaps at this point, my last) Java program!

Some links for you to check out:

http://isd.cme.nist.gov/projects/emc/

http://ascc.artsci.wustl.edu/~jmelson/machining.html

http://www.ktmarketing.com/CNC.html

http://www.erols.com/mshaver/index.htm

Root through these and get back to us with your comments and questions!

Thanks,

Matt Shaver
mshaver@...
(410) 521-3715