This is a late alog from yesterday when the alog was down.
Sheila, Elli, Dave O, Alexa, Evan, Daniel
This morning when we arrived all the control room computers were off, the
PSL was down, and the alog was down. Over the phone Dave walked us
through restarting cdsfs0. The PSL watchdog had apparently tripped, although
Elli and Dave O trended the power out of the diodes (H1:PSL-NPRO_D1PWR and
H1:PSL-NPRO_D2PWR) and they didn't seem to be dropping before the watchdog
tripped.
We also had to adjust the Y arm fiber polarization.
We installed the common mode summing junction which Filiberto repaired 2
weeks ago. Channel B seems to be busted, the output is railed with a small input. Evan and I pulled the
board and put it in Fil's office, we asked Richard and Fil for a spare so
we can try locking tomorrow.
We also switched the order of the filters in ETMX L1 so that both boosts
are before the control filter. We are hopping that this will help relieve
the intermittent problem that DIFF loses lock while engaging the boosts.
We added a new MEDM screen, which has an overview of the ISC guardians used for full locking attempts.
There is a small and large version, they are both linked from the guardian overview screen.