Re: EMC following errors

[Ray <rehenry-at-up.net>]

On Thu, 20 Jul 2000, Bill wrote:
> RAY
> 
> Thanks for the ini file, I'll look it over and do some more testing.
> the rest of the replies are in the message.
> 
> Ray wrote:
> > 
> > On Wed, 19 Jul 2000, Bill wrote:
> > > A couple of questions about EMC
> > >
> > I've had a problem of late with steppermod on my 2.2.14 kernel.  I loose
> > several of the values in the ini file whenever I get an error message
> > from the motion stuff and EMC attempts to write its current values to the
> > ini file.  It does the same when I shut EMC down.
> > 
> 
> I noticed the same thing, I thought I was cracking up. Has emc allways
> written to the ini file, or is this new?
 
This has been around for a while.  My guess is that this is a first step
toward auto tuning.  There were several posts on how it is done a few
months back.
 
> > You can check this with your system by setting values for p i d in the ini
> > file and starting EMC.  Under the settings menu press calibration and see
> > if your pid settings are shown there.
> 
> they're not
> 
> > 
> > If they are not, we need to fix steppermod.  I've been using freqmod
> > instead for a couple of releases now.

Your's is the second confirmation that all is not quite well with the
calibration part of steppermod in the recent 2.2.13 releases. 
  
> I would like to use freqmod and tkEmc but they seem to use a more
> processing 
> power than steppermod and xemc. I can get more speed out of it with xemc
> and
> steppermod. The mouse pointer gets real jerky with them running and high
> max
> velocities in the ini file. I guess a faster computer is in order.

I'd also use steppermod because it works well with my light loads but
can't with this problem.  
 
> > > A positive movement works great at that speed and I can go
> > the full > length
> > > of travel on either the X or Y axis. When I try to go back I get a
> > > following
> > > error before the axis even moves (or within a couple steps). What is the
> > > difference
> > > between the two moves? Fixes?
> > 
> > The only thing I can think here is min and max output aren't set to the
> > same values.  These variables are in each of the axis definitions.
> > 
> 
> I have a 2.0.36 and a 2.2.13 version on seperate drives. I've noticed
> this 
> problem with both setups. I'll check the ini file tomorrow and see what
> I
> can figure out.

There was another effect of the steppermod calibration problem on my
setup and that was that I got other stuff (MIN_FERROR) set to 0.000 and
couldn't get any motion without error.  Part of the problem is that I have
gotten into the habit of copying my run and ini files from one setup to
the next.  I just didn't study that file enough to see the problems.

Ray