Naoki, (Nutsinee remotely), Vicky

We've had issues transitioning the filter cavity IR locking this week, and we've so far tracked it down to the combination of this week's computer restarts, the addition of FC beam spot control last week (LHO:69374), and LVEA temperature drifts. Our computer issues this week seem to be because we were not monitoring our ZM+FC P/Y slider offsets in SDF, especially we were not monitoring most of these in safe.snap. We are now monitoring all ZM{1,2,3,4,5,6} and FC{1,2} P/Y slider offsets in safe.snap and in OBSERVE.snap, see attached screenshots of accepted SDF's.

Longer story of what we think happened: Computer restarts caused SQZ+FC alignments to come back online quite misaligned, with both SQZ-->IFO and SQZ-->FC misaligned, and so our SQZ LO OMC locking was unreliable, which causes the FC-IR lock handoff to fail. SQZ-ASC (on AS42) would try to realign squeezer to IFO, but at the same time FC ASC would engage, and further confused all the FC+IFO SQZ ASC. Nutsinee finding the LO struggle to lock on OMC helped find the SQZ-ASC as a problematic thing, which helped track down the ZM restart issues. Overall, this resulted in each FC-IR locking attempts aligning the whole system slightly more every time it tried to engage ASC, but quickly the FC-IR lock transition would fail in seconds as all the alignment moved, which would bring the squeezer down, and then the whole thing would start over. So, after many re-locking attempts, the incremental alignment improvements each time eventually allowed the whole squeezer alignment to converge after tens of minutes (ie, the squeezer eventually managed to re-align and re-lock itself to the IFO after tens of minutes of trying and making a little progress each time).