jenne.driggers@LIGO.ORG - posted 13:50, Tuesday 03 January 2017 - last comment - 19:03, Wednesday 04 January 2017(32923)
Dark offsets set
I reset the dark offsets for all LSC and ASC PDs. The ASC diodes already had scripts in ..../userapps/asc/common/scripts/dark_offset/, so I copied the style of those into an LSC script that now lives in ..../userapps/isc/common/scripts/dark_offset/.
I also created a bash script that will call each of those scripts in succession - it's natively in the isc folder, but linked in the asc folder: all_offsets_LSCandASC.
For last lock, and the one that Ed just got, we've had SDF diffs due to not rounding in one of the pre-existing dark offset scripts (the one that does the end station QPDs). The diffs were of the order 1e-16, so were just accepted so that we can Observe. I have modified (although not run, since we just locked) the script such that we have rounding. This should prevent the problem in the future. Next time we lose lock and I'm around, I'll try to remember to hand-round those values so that we don't keep getting non-useful SDF diffs.
Also, Ed might write about this in his shift summary, but it seems like the ASAIR_LF offset was set a little wrong. Sheila and Ed took the IMC to offline and hand-set that offset, and we were able to get through the PRX_Locked state of initial alignment. (The wrong dark offset was causing the output to not meet the guardian's threshold of whether the cavity was locked or not, even though it was locked).