travis.sadecki@LIGO.ORG - posted 18:46, Sunday 09 July 2017 - last comment - 20:11, Sunday 09 July 2017(37399)
OMC DCPD saturation alarms
VerbalAlarms has been announcing "OMC DCPD saturation" every few seconds for ~10 minutes. I have never received this notification without a lockloss following. This is not the case today. Not sure what to do about this.
Since around the time the OMC DCPD saturations began, our range began a steady decline. Possible contributing factors could be increasing wind (at ~30 mph now) and an EQ that showed up on the BLRMS ~30 minutes after the saturation alarms began. The EQ is rather small (0.2 um/s at 0.03-0.1 Hz), so I wouldn't expect this to be an issue, but not helping either. We finally lost lock at 2:48 UTC as the range was approaching 15 MPc. The fundamental violin modes did not appear to be ringing up during this epoch and the higher order modes also appeared to remain about where they had been. Maybe H1 just needs a reboot, hopefully.
While relocking at DRMI_ASC_OFFLOAD, the HAM 6 ISI and OMC WDs tripped.