Sheila, Georgia,Craig

We had some difficulties earlier tonight probably because it was windy and now things have quieted down.  

We did a few things to get locked:

• We noticed that in the PRMI to DRMI transition, the SRCL feedback is applied before the suspension has even been aligned.  This is because we were waiting for the suspension guardian to "arrive" before asking DRMI to lock.  Now I've added a check for the supension guardian (ALIGN_IFO) to be done before making the request of ISC_DRMI, and this has prevented us from sending a signal to SRCL before the suspension is aligned.  It looks like there is an instability in PRMI between 100 and 150 Hz when we start to align SRM, so if we want to investigate this further we should try turning the PRCL gain down before we align SRM. 
• The DRMI locking has been slow, we noticed that the limit is on for the beam splitter but the low pass is not.  We have changed this back and forth a couple of times in the last few weeks, but I think that these two things should come as a pair (both on or both off). (I think the low pass is intended to mitigate some of the high frequency junk we get by enforcing the limit).  Old alog about the limiter: 16522
• We had two locklosses while engaging the soft loops tonight, which were due to CSOFT P.  The problem was that in PREP_ASC_FOR_FULL LOCK the filters are set fo the new configuration, they are reset in ENGAGE_SOFT_LOOPS, but the filters have 2 second ramps and we weren't waiting 2 seconds before turning the loop on.  We also added an offset in CSOFT P, of 0.07
• We tested our changes to ANALOG_CARM from last night, 44272 they are fine. We had one lockloss while powering up to 15W, which we think is due to the gain stepping in the common mode board.  Craig did a test by moving 6dB of gain upstream, but don't see a change in the size of the glitches as we change the analog gain. 

Working on powering up:

• We powered up to 15W once, and turned both CO2 lasers to 0W to see if this would improve the snowman mode we are seeing on the AS camera.  We lost lock after about 15 minutes.  
  • We would like to finish setting up the AS port OSA to tune the differential CO2.  We also can see that we need to retune the soft offsets after powering up.