MDM Trouble Report for 2016 Jul 01

Telescope: 2.4m
Observer(s): Edmund Hodges-Kluck (Michigan)
Instrument: OSMOS

Problem(s) Encountered:
The guide probe/MIS had a problem in which sometimes either the
X or the Y coordinate could be increased but not decreased. At
the same time, the guide probe *could* be successfully moved to
the origin, and the guide probe was successfully moved from the
origin to a variety of guide stars at different positions. However,
in these cases the xmis2 panel warned  Y not at CCW limit 
(with an analogous message for X). 

The problem was initially with the Y axis, but resetting or
re-initializing the xmis2 panel led to the same issue in either
X, Y, or both X and Y, and I couldn't discern a pattern in the
failure. Then, I power cycled the MIS from the control room and
restarted it, but had the same problem. 

The increase-but-not-decrease problem affected both the dx/dy
and absolute X/Y inputs, but the probe did not get lost -- it
found stars from JSkyCalc. I thought that it might run into 
problems with stars close to the edge, but the probe position
did not seem to affect the problem. 

Finally, after my target had moved to an airmass that was too
high I moved to a different target. The problem remained, but
after cycling the MIS power one more time everything worked
and remained thus for the rest of the night.

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Submitted on 2016 Jul 2 [5:30:53]