Jenne Driggers, Ryan Short, Sheila Dwyer, Jim Warner

In several of the locklosses that TJ and Ryan had early this morning, the PRG would drop before we started to engage ASC, and we would loose lock while the ASC loops came on.  By pausing and going line by line through the guardian we identified that turning on the DARM offset was causing the drop in PRG.  We were able to engage the ASC without issue when the DARM offset was off.  At this point we did a series of OMC scans, attached screenshot, but everything seems normal here.

Our hypothesis is that the DARM offset was too large when the alignment was off (and perhaps some microseism makes things a little less stable), but that things are fine once the ASC is on. 

For this locking attempt I've moved the DARM offset state to after ENGAGE_ASC.  We had initially moved it to before ASC a long time ago to save time by locking the OMC while the ASC was being engaged.  But, if this causes locklosses while we are engaging the ASC this isn't worthwhile, and we can let the OMC lock while we are waiting for the soft loops.  I had a look at the lockloss tool to see how often we've been loosing lock from this state, it say we lost lock from ENGAGE_ASC (429) 8 times since March, but this only includes one lockloss from last night.

I'll leave this guardian change in for now.

While we were looking into this, Jim made changes to sensor correction and CPS DIFF.  This might have been helpful, based on the locking progress it's hard to say because his changes happened as we were understanding that the DARM offset was the issue.