0:55 H1 Bumped OUT of Observing.
This was found to be due to an "unlocked TCS_ITMy_CO2 laser". Looking at NDScope (see attached screenshot), the laser power took a jump up from ~50.16W and the TCS_ITMY_CO2 guardian node spent a few minutes at the FIND_LOCK_POINT adjusting an offset (see attached pdf of log file). Eventually the guardian returned to its nominal state, of LASER_UP (at 1:01utc). It had a "new pzt setpoint of 50.536W".
At this point, it looked like everything was good to go to Observing, so at 1:06utc, I returned H1 to Observing.
Summary: TCS ITMy CO2 laser was unlocked for a few minutes & Guardian restored laser. However, laser power changed from 50.16W to 50.536W. I have not seen this before.
This is normal. When the CO2 laser goes to reacquire lock, it will scan with its PZT to find a point where it has good buildup. This point changes from lock to lock due to a variety of reasons, so it's possible to have slightly different powers from the laser itself. [[abs(50.16 - 50.54)/50.16 = 0.76% change]]
Not too big of a deal since we control the power down stream anyway.