TITLE: 11/03 [EVE Shift]: 00:00-08:00 UTC (16:00-00:00 PDT), all times posted in UTC STATE Of H1: Lock acquisition OUTGOING OPERATOR: Jeff QUICK SUMMARY: Lights appear off in the LVEA, PSL enclosure, end X, end Y and mid X. I can not tell from the camera if they are off at mid Y. Winds are less than 10 mph. Appear to be increasing. ISI blends are at Quite_90. Earthquake seismic band is between 0.01 and 0.02 um/s. Microseism is between 0.1 and 0.3 um/s. Jeff has been having trouble with ITMY bounce and roll modes. Has been stopping at REDUCE_CARM_OFFSET_MORE to allow Jenne and Evan to investigate.
The roll modes have been conquered. When they were too high, the DHARD loops become unstable and we lose lock. We stopped at REDUCE_CARM_OFFSET_MORE, which was the highest state that we could sit at without losing the lock.
ITMY's roll mode was the worst offender according to the monitor screen, so we only worked on damping that mode. We used the usual filter settings (which are always left in the correct state) and the usual negative sign for the gain. The usual gain that guardian leaves the ITMY roll mode damping is -40, but I was using larger gains to get the mode to go down faster. Once the roll modes were all around the "okay" level on the monitor screen, we let guardian continue the locking sequence.
We were concerned at one point that guardian had frozen on us, but it turns out that we were just being fooled. It looked like guardian was not finishing the DC_READOUT.main state, and not even starting the DC_READOUT.run state. However, it was all fine. I think I have been fooled by this before, but as a reminder (to myself especially), if an EPICS value is not going to change, guardian will not log that it tried to write the value. So, the last few steps of the main sequence were to write some gain values that were not going to change, which is why it looked like it was just stuck. Also, there was nothing in the run part of the state that was going to cause any log messages, so it didn't look like anything had happened, even though we were already getting the "return true" at the end of the state. In the end, we just requested a higher state, and guardian moved on as usual.