Experimental Physics and
Industrial Control System

Maren Purves <[email protected]> · Tue, 02 Sep 2014 10:59:44 -1000

On 09/01/14 03:55, Mark Rivers wrote:

Hi Peter,

I think the problem is that the motor record should ignore both soft
limits and hard limits during a homing sequence.  Soft limit
violations are expected because the controller does not yet know
where the motor is, and hard limits are also to be expected because
sometimes the homing operation involves hitting the limit switch, as
in your case.

I have had problems with the motor record stopping a motor when a
soft limit is exceeding during a homing operation too, but I believe
that has been fixed in a recent release.

Hi Mark,

I have one problem here: in my book the term "hard limit" means that
you can't physically move past that point without breaking something,
it is a physical end stop. (I have heard of that happening. That
particular telescope was out of commission for several weeks)
Datum switches should be a reasonable distance away from soft limits,
and hard limits should be further away from the datum switches than
that.
Obviously, circular mechanisms may or may not have these limitations,
but linear ones always do.

??

Maren

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System