Date: Thu, 7 Dec 2000 09:18:02 -0700 (MST)
From: Craig Loomis
Subject: Re: 3.5m Night Log 20001206
  There is no such thing as magic, only hardware problems and software bugs.
This was a software bug: the instrument is fine and never needed to be
power-cycled. Recent changes to support Grim polarimetry were not thoroughly
tested, and certain FITS cards were left "blank". In particular, BSCALE was set
to 0, so IRAF showed all pixels as 0. So it looked like the instrument was
misbehaving.
  The silver lining is that after being power-cycled, the instrument
is now reporting correct temperatures again.
 - craig
>  18:30. I had problems with the GRIM taking images (Russet came online
>  about the time I was examining the test images).  We worked on power
>  cycling GRIM to no avail for about 30-40 mins and then called Craig.
>  Craig worked his magic (Had me power cycling computer/instruments/fibre
>  boxes as well as him doing some magic, it seemed to be a FITS header
>  problem) and we had GRIM back online by 20:55 for science.