Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/ops/swat/safing/08254/wfpc2_update.txt Дата изменения: Thu Sep 11 13:57:08 2008 Дата индексирования: Sun Mar 2 02:54:11 2014 Кодировка: Поисковые слова: m 8

Date: Wed, 10 Sep 2008 21:46:55 -0400
From: Chris
Subject: WFPC-2 Recovery

OPM,

Following the earlier error(s) WFPC-2 was left between modes. It has
been placed into Safe mode using real-time commanding. The problem(s)
appear to be understood.

The first error was the AFM turn on temperature. The NSSC-1 requires
the AFM electronics to be sufficiently warm prior to turning them on.
The CARD used to require >10C but that has been lowered to >2C as an
outcome of lowering WFPC-2 operating temperatures to compensate for
detector bias degradation. Apparently the request was not made to
update the PDB for this value so stored commanding generated an error
when the actual temperature was below the old value of 10C when AFM
electronic turn on was attempted.

A second problem has been identified due to the WFPC2 code physically
being shifted in memory for this FSW installation. There is a section
on code that looks at a specific memory location for a checksum = 55.
That particular memory location is now owned by WFC3 so the value is
currently zero.

At last word it sounded like solutions to both problems have been
identified. There will be a conference call at 8:30AM.



Chris