Sheila, Ed

Summary:  I've moved the gain decrease for INP1P to the LOWNOISE ASC state, so that we have more gain for this loop while powering up, and in DRMI I added checks on the DC centering loops before engaging ASC in DRMI or PRMI.  I think that the change to INP1 wil help aviod some of the locklosses from INCREASE POWER, but haven't done anything to address the other locklosses.  

DRMI centering: Ed had one lockloss where the DRMI ASC came on even though the AS centering loops were saturating.  I added check for the DC centering loops in both PREP_PRMI_ASC and PREP_DRMI_ASC, so that now the guardian should not move on if the OMs are saturating.  If this happens, operators will have to clear the saturations before the guardian will move on. 

ASC locklosses:

Last night Corey had several locklosses that seemed to be ASC related, in ENGAGE_ASC, ENGAGE_SOFTLOOPS, or INCREASE POWER.  Several of these seem to be similar to the plot attached to 51868

I made a few unsucsesful attempts to increase the gain of INP1P durring ENGAGE_ASC.  Even with no low passes engaged, INP1 P will ring up an instability around 1 Hz (0.8-1.1 Hz) with just a 6 dB increase in gain, with the gain settings that it has at ENGAGEASC (-30dB, low pass, integrator in suspension).  So we haven't made any changes to ENGAGE_ASC for now. 

engage soft loops:  One of Corey's locklosses happened right as the ETM dither loops came on, CHARD Y error signal drifted away from 0.  Another happened when the SRC2 gains are ramped down after the integrator.  There is also 5Hz oscillation in DHARD P which seems to happen as we move the spots towards their final position, for about 20 seconds, and causes saturations of the OMs and OMC.  I didn't see that cause any locklosses, although we might be able to move through this faster by increasing the gains of the ADS loops before we move the spots. (currently they are increased after the spots are moved).  

We did all the steps in ENGAGE_ASC and SOFT LOOPS manually, leaving the gain of INP1 P high (it is normally reduced by 20dB at the end of the soft loops.  When doing this manually I also had the low passes off for INP1.  The first attached screenshot is one of Corey's locklosses from yesterday during increase power 1252146916 where the INP1 P error signal was far from its lock point, and the second screenshot shows our power incease today with higher gain in INP1P.  I've changed the guardian to use this higher INP1 P gain during the power increase.