Guide Probe Stage Motion Failure

Tuesday, June 13, 2017 12:32 PM

Problem(s) Encountered:

The guider stage became unresponsive several times during the night and did not actually move when sending moves from JSkyCalc.  I tried sending the probe back to the origin, but each time it refused to go back in one axis.

The solution was to reboot the MIS controller.  I had to do this three times, losing ~10 minutes each time.  I noticed that when it froze, there was a warning message on the XMIS2 GUI:

WARNING: Not at Y CCW Limit

I think the freezing problem has happened with both the x and y axes.


I ran some tests in hopes of seeing what happens when the guide stage fails.

Demanded movement through the xmis2 GUI, first in x-, then in y-, then in both at the same time.  No issues.  I then went out to the dome and watched the guide probe while moving it around.  Nothing seemed amiss.  Next, I pointed to various positions in JSkyCalc and demanded the probe to go to those positions.  Again no issue.  Did this throughout much of the day between other tasks and never had any issues.  I’ll move it some more as the day proceeds, but not sure what else to try as for now.  

Also popped the top of the MIS and the MLynx units all look good with a solid green LED each.

Subsequently, I believe Ryan reported two more failures over the remainder of his time on the 2.4m.  So far, to my knowledge, John has not seen this issue during his program.