This software is called in the subroutine lr_break when a command load is to be interrupted. This first collects the previous directory information from the current ACIS-History.txt file. This information is stored in a string. Then it uses the history files from the previous directory to find the state of the spacecraft at the time before the interrupt. If the -h option is set, the software will place HRC at the focal plane regardless of the history file position. This reflects what has actually happened on the spacecraft. The new history file is placed in the current load directory with the name ACIS-History_edit.txt and is to be used in acis-backstop.pl.
In addition to the history file, there is a ACIS-Perigee.txt file that is modifed in a similar manner. The ACIS-Perigee.txt file records the radmon disable time, the last detector housing heater off time (no longer used), the last detector housing heater on time (no longer used), the time the detector housing heater was on (no longer used) and if the radzone triplet was recorded. The last item is used mostly when the command loads end during a radzone passage and we need to know if the instrument was properly set before the passage. If this file is edited, it will be ACIS-Perigee_edit.txt.
Author:
Nancy RA Wolk.