Locked about 5 hours into day shift - a continuation from owl shift.
LLO down and commissioners arrive, so went to commissioning mode.
Excitation broke the lock.
IFO relocked with only a tweak to the BS alignment for DRMI.
Commissioning continues, but this lock does not have an extra stage of whitening on the OMC - see note below.
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OMC_Lock has a new stage ADD_WHITENING
This is added after the IFO reaches Nominal_Low_Noise, BUT
H1:OMC-DCPD_A_IN1 and H1:OMC-DCPD_B_IN1 need to be less than 3000 counts peak to peak, or adding the extra whitening will saturate... and bad will happen like lock loss or increased noise
There was a DMT glitch around 2015-08-22 21:00:00 Z. Our previous range channel disappeared, and the seismic FOMs dropped out for 10 minutes or so.
As Cheryl says, in order to turn on an extra stage of whitening, OMC-DCPD_A_IN1 and OMC-DCPD_B_IN1 must each have an ac peak-to-peak less than 3000 ct. Otherwise, turning on more whitening will saturate the ADCs. If the peak-to-peak is more than 3000 ct, probably it is due to some violin mode(s), which must first be damped.
Probably it is a good idea to wait until nominal low noise to activate extra whitening.