In order to easily assess the fast shutter during operations, I added code to the DIAG_MAIN guardian that is watching for orm power drops, and if it finds one, it writes out a text file that can be ingested by the lockloss tool.

The medm button that calls up the plot is on ISC_GUARDIANS.adl for now.

Related files In /opt/rtcds/userapps/release/sys/h1/scripts:
===================================================
fastsutterlockloss  : wrapper file that launches lockloss
channels_to_look_at_FastShutter.txt : lockloss channel file for the fast shutter
FASTSHUTTERTIMES.txt  FASTSHUTTERTIMES_1.txt  FASTSHUTTERTIMES_2.txt  FASTSHUTTERTIMES_3.txt : files containing the timing information for the last four arm power drops.

Related code in DIAG_MAIN:
==========================
# this check finds an arm power drop, and creates a text file for plotting the fast shutter performance
fastshutterMemory = {
        'LOCKED'   : 0,
        'ARM_ON'   : 1000,
        'ARM_OFF'  : 800,
        'TIME_LAST': 0}
@SYSDIAG.register_test
def HAM6FASTSHUTTER():
    armon =fastshutterMemory['ARM_ON']
    armoff=fastshutterMemory['ARM_OFF']
    lockedpast=fastshutterMemory['LOCKED']
    timelast=fastshutterMemory['TIME_LAST']
    arm=ezca['LSC-TR_X_NORM_INMON']
    timestr=gpstime.tconvert()

    if arm > armon:
        locked=1
    elif arm < armoff:
        locked=0
    else:
        locked=lockedpast

    # upon dropping arm power: record time window for plotting
    if locked==0 and lockedpast==1:
        dur=int(float(timestr)-float(timelast)+1)
        filefs='/opt/rtcds/userapps/release/sys/h1/scripts/FASTSHUTTERTIMES.txt'
        filefs1='/opt/rtcds/userapps/release/sys/h1/scripts/FASTSHUTTERTIMES_1.txt'
        filefs2='/opt/rtcds/userapps/release/sys/h1/scripts/FASTSHUTTERTIMES_2.txt'
        filefs3='/opt/rtcds/userapps/release/sys/h1/scripts/FASTSHUTTERTIMES_3.txt'

        os.system('mv '+filefs2+' '+filefs3)
        os.system('mv '+filefs1+' '+filefs2)
        os.system('mv '+filefs+' '+filefs1)
        f = open(filefs, 'w')
        f.write('plot -w ['+str(-dur)+',1] '+timestr+' ')
        f.close()
        yield "New Fast Shutter plot availabe!"

    fastshutterMemory['LOCKED']   =locked
    fastshutterMemory['TIME_LAST']=timestr