Sheila, Kiwamu, Alexa, Evan, Nergis
After locking the x-arm in green (alog) and testing for the x-arm losses (alog), we repeated our usual initial alignment procedure. Some comments:
We were able to lock ALS COMM very easily; however, we had difficulties locking DIFF. At first we thought we had found our culprit: LSC-DARM had FM10 engaged, which should not have been; the LSC-DARM filters should be FM5, FM7, FM8 with FM3 turned on later. Even after we noticed this, we still could not lock DIFF. As soon as the DIFF engages (even with gain's of 1, relative to the nominal 400), we would immediatly lose lock. We ensured that the ETMX ESD was working by sending in an excitation to the bottom stage in both pitch and yaw; this was successful and we did not see any large Y2P or P2Y coupling. We did not take L1, L3 crossovers, which we should do tomorrow. We also had trouble getting the DIFF PLL in range -- the old guardian tidal scripts the Nick wrote have been decommissioned, and we were not yet ready to implent Daniel's new tidal feedback, so we were left to using an ezcaservo in the test offset. This did not work very well, and limited us from figuring out what was wrong with DIFF. It's possible that there are still some more inccorect filter/gains setting.