MDM Trouble Report for 2006 Mar 4

Telescope: 2.4m
Observer(s): Peeples, Molly (Ohio State)
Instrument: 8k

Problem(s) Encountered:
Guider:

This is the guider with the 8k camera...  For the first observations
of the night, I was guiding with the  South  camera and it was working
fine.  For the next observation, I needed to use the  North  camera
(in order to fix the pointing as it was at an earlier epoch) and... it
didn't work.  The first four or five seconds would be fine, and then
the telescope would start systematically moving away (usually the star
would move up and to the right on the tv screen).  There isn't much
troubleshooting information that I could find in the manual, so I
tried such things as turning off and then on auto guider, changing the
box size, changing the guide rates and guide times, but nothing
worked.  Doekkun (who was observing at the 1.3-m) came up and figured
out that the guider focus box/paddle/thing doesn't work; we couldn't
get the guider to react to anythin from the baddle at all.
Coincidentally, the guider focus and the telescope focus were offset
slightly, making the stars look elliptical.  This, however, only
seemed to be for the North camera, as the stars were nice and circular
with the South camera.  After an hour and a half, we gave up, and I
observed the rest of the night just on the fields for which I had
guide stars in from the South camera.


Oh, and I'm not sure if this has to do with the guider or not, but
several times during the night, the telescope wouldn't slew to the
sent coordinates.  It would stop about an arcminute in RA before it
got there, sometimes complaining that the RA and/or DEC encoders were
lost.  Usually sending it to the nearest bright star and then back to
the initial coordinates would fix this, though.  The message about the
lost RA and/or DEC encoders would also sometimes show up during a
guided exposure.


8k:

So at some point immediately after doing a  go 3  I realized that I
hadn't changed the filter.  With saint-like levels of patience, I
typed  quit,  and then  abort,  and then probably  abort  again.  I
might have tried typing in the filter change as well, and even
pressing enter after it, as usually the DetCom seems to be able to
handle caching advanced commands, but... instead it crashed.  Just
disappeared from the screen.  The manual, from what I could tell even
after extensive reading, never really says how to load the DetCom, but
eventually I figured it out.  And then it couldn't find the
instrument.  After pressing  enter  at the DetCom prompt it would give
a yellow warning message saying something to the effect of,  There is
no instrument to test data link.   So Doekkun came up again.  We never
found anything in the manual that had this particular error message;
most were either said to be in red, and/or referring specifically to
MASTER and SLAVE.  At some point when we had restarted the DetCom,
hiltner just froze and we had to reboot it.  That was fun.  Due to a
lack of other options, we chose to follow the instructions for the
case of failing exposures.  The first suggestion is to power off the
detectors manually, wait a bit, and then turn them back on.  Oh, and
DetCom didn't believe that  pon  and  pof  were real commands at this
point.  Also, the black power switches/buttons were really hard to
find... at first we turned off some white box sitting on top of SLAVE.
We're not sure what that box does, and we hope that turning it off and
then turning it back on didn't hurt anything.  (We turned it back on
after turning MASTER and SLAVE back on the first time, once we'd found
the real switches.)  Long story short, that didn't work, and we went
through all four contingency plans.  Step 4, by the way, didn't make
any sense, so we just logged obs24m out of vesuvius, did a cold
reboot, and followed the rest of the instructions.  Lo and behold that
did the trick, and DetCom began to believe that the 8k detector did in
fact exist.  All in all, it took two hours to fix that.

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Submitted on 2006 Mar 5 [7:19:02]