Date: Tue, 26 Feb 2008 10:40:09 -0700
From: Dan Long
Subject: Re: 2.5m obslog 20080225 (MJD 54522)
>                        APACHE POINT OBSERVATORY SDSS 2.5M
>
>                                  OBSERVING LOG
>                             Monday February 25, 2008
>
>                                   (MJD 54522)
>
>---=== OBSERVING TEAM ===---
>
>         Audrey Simmons
>         Steph Snedden
>
>         Jon Brinkmann (support)
>
>---=== OBSERVING PLAN ===---
>	Science!
>---=== OBSERVING SUMMARY ===---
>
>Science with moon and crummy seeing. Useful signal obtained on three
>plates, but no plates finished.
>
>---=== OBSERVING LOG ===---
>
>Afternoon:
>----------
>On the first bias of the afternoon, we got an error message about an ongoing
>exposure on sp1. Sure enough, when we went to check the mechanicals status at
>the telescope, both sp1 and sp2 said they were doing a 1200s exposure. That is
>the exposure time of the last exposure we took last night, which we aborted
>because of clouds and high wind. Apparently, the abort did not complete
>properly. A power-cycle of the mechanicals for both spectrographs fixed the
>problem.
    Looking back at 54521's murmur log, there was a pauseStare issued
at 07:52:14Z which completed successfully.  There were two more
pauseStare commands issued a short time later (07:52:25Z, and
07:52:52Z) which failed, because the exposure had already been paused
(3 of the same command; maybe an indication that all was not well
with sopGUI?).
    There is no evidence in the murmur log of an endStare -abort.  So
the spectrographs waited patiently for about 15 hours with the
shutter closed, the hartmann doors open, and 1169 seconds on the
exposure counter, before complaining about an ongoing exposure when a
bias was attempted the next day.  Assuming an endStare was issued, it
looks like another instance of a communication failure between sopGUI
and the rest of the world, as no endStare was seen in the murmur log.
    Fortunately this was not a recurrence of the sp1 mechanicals
weirdness seen 10 days ago.  Also, as was mentioned in the summary of
that event, if you see an "ongoing exposure" on a spectrograph
(especially if it is only on one) that you don't think should be
there or you want to get rid of without going through the DA, a
"mechSend S" command should clear it.
				Cheers,
				  Dan