Re: New EMC Release

[Jon Elson <jmelson-at-artsci.wustl.edu>]

Fred Proctor wrote:

> I posted a new release of the EMC software on the FTP site. This fixes
> Jon's problem with the G92 axis offsets getting clobbered when the
> program ends. According to the RS-274-NGC spec this is what is supposed
> to happen, but since these offsets are not stored anywhere and can't be
> recovered, I decided to hell with the spec.

Very interesting!  I will have to look it up.  But, I can say with absolute

certainty that the Allen-Bradley 7320 does NOT clear the G92 offset when
a program ends.  In fact, I think the only way to clear it is to turn the
controller off (or have something else happen that causes a position lost
condition.)  Thanks,  Fred!

> I also fixed a problem that occurred when switching from MDI to manual
> mode, while a move was executing, that put you into auto mode instead.
> Jon did this to set the feed override for an MDI move, since the 0-9
> keys no longer function as feed override accelerators in MDI mode. Note
> that switching into manual mode aborts any motion, since the motion
> system can't handle simultaneous free axis and coordinated axis motion.

Ahh, I suppose that makes sense, although I seem to remember that
keystick allws you to do this.  (But, it may fake it.)

> To change the feed override in MDI mode, you must use the mouse. I
> propose getting rid of the use of the 0-9 keys for feed override, and
> replacing them with Alt-0-9 or Ctrl-0-9. This would work in MDI mode.
> Comments?

Yes, something that would be available all the time would be useful.  On
the
other hand, when you need to slow things down right away, having to
hold a modifier key would be cumbersome.  But, maybe that is the best
we can do with a keyboard.

Thanks,

Jon