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To Matt and List: I'm new here....guilty as charged!
My experience with Bestsoft has been the same as what you have shown
from others. I kind of made the assumption that I was the only person
Mr Bestsoft didn't want to deal with...usually the lack of interest in
support becomes obvious AFTER one purchases something. Thank you
very much for taking the time to pull together those posts.

Guess its time to start learning Linux and EMC...

Two questions regarding the above (apologies in advance if they're
silly questions!)

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?
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?

Thanks,
Jon Pritchard



-

Date: Wed, 9 Jun 1999 01:23:56 -0400
From: "Matt Shaver" <mshaver@...>
Subject: Re: Commercial software

From: "Jon Pritchard" <jpritchard@...>

I've been looking for "cheap end" software that I can

retrofit<SNIP>

So, uh, you're new here right?

I tripped over a website with a good looking software package:

I've been trying to get ahold of someone at Bestsoft for several

days,

both leaving messages and email. A couple emails over the past

several

months have gone unanswered. Is this outfit for real? Is this

indicative

of the level of service customers can expect? Did they go fishing

and

forget to change the message on their machine?

-----
I think you should send Bestsoft some e-mail and request a brochure.

Let us

know how you make out!

Matt Shaver
mshaver@...

Jon Pritchard wrote:

Guess its time to start learning Linux and EMC...

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?

Yes, I'm very sure it could be integrated at several different levels
of complexity. You could just program it in C, and add it as another
task. or, you could write a simple language to handle the functions
you need. This is apparently in the works, but not front burner.

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?

I'm not sure what you are asking for, here. Do you mean 'graphical
programming', where it draws the part as you specify the moves,
bolt circles, etc.?

Jon

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



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



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:



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:









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

Thanks,

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

About EMC, writing PLC programs for things like tool changers, and
custom GUIs, Jon Pritchard wrote:

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?

Matt Shaver gave a good synopsis of this. The current EMC has a PLC-like
controller, generically called "emcio" in the documentation, with
executables "shvio", "mmio", and others. These are Linux processes
(don't run real-time), cycling at a configurable rate that can run at
about 20 milliseconds per cycle at their fastest without resorting to
CPU soaking or hacking the Linux kernel (both which I've done). The
difference between shvio ("Shaver IO") and mmio ("Minimill IO") is that
shvio talks to the parallel port for digital control of spindle on/off,
speed increase/decrease, and direction, and for coolant, lube, and estop
handling; while mmio doesn't have any coolant or lube and uses an analog
control of the spindle.

These are coded in C++, using some templates that we at NIST use on many
of our projects. These templates follow our Real-time Control Systems
(RCS) methodology, with which us NIST people are familiar. Writing a new
PLC-like controller from scratch this way is a pain in the neck for most
people.

Any programming language can be used to build a PLC that works with EMC,
with the following constraints:

1. It has to run with Linux. Linux supports most languages, e.g., C,
C++, Perl, Tcl/Tk, Java, Python, FORTRAN, etc. but these are not PLC
languages. Does anyone know of a ladder logic programming environment
that runs in Linux? University code? Alternatively if a ladder or
IEC-1131 programming environment can generate C code as an output, this
could be copied to a Linux box, edited where necessary, compiled, and
run. Something like Wizdom's Paradym-31 could work like this.

2. It has to include some way to read commands and write status, using
any of the Unix interprocess communication methods, or sockets, or
something like that. If it's C/C++/Tcl/Tk/Java/Python code then no
problem. If it's a standalone PLC then it must have some way to send it
commands. If it uses a serial port then that would work also.

Ideally there would be a Linux version of a PLC programming environment
with a software interface for commands and status. Ideally also means
free, like some university project.

Also, question 2:

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?
<

The EMC has an X Windows GUI with menus, buttons, etc. I wrote this in C
using the X Toolkit library. I modify this all the time but it's not
drag-and-drop GUI building, to say the least. We also have a Jave GUI,
and Matt Shaver has done some Java work too. This is a better way to go
than the X Toolkit. We had some problems with Java 1.1.X earlier, but
Java 1.2 is out and the problems seem to be solved.

One alternative that some have mentioned is Tcl/Tk, the scripting
language for building GUIs. Any Tcl/Tk programmers out there? There's
also the QT library from Troll Tech that can be used to build GUIs that
can be ported between Unix and Windows machines. The KDE desktop
environment that runs on Linux uses this.

--Fred