Fil and I went to EX to look inside the BRSX enclosure in prep for the work next month. While we were there I touched up the centering of the BRS. While we had the box open, we must have disturbed the cable into the interface box inside, because when we got back to the corner station the BRS wasn't damping down. I went back down to look at it and it took a little to realize there is not retention on the ethercat cable into the interface box, so it's really easy to knock loose. It immediately started damping down when I pushed the ethernet cable into the interface chassis.
The BRS is still calming down, so we shouldn't use it for a little while yet. The operator should watch the the BRS health ndscope and wait for the BRSX RY OUT to look more like the BRSY RX OUT signal, i.e. the blue trace on the middle timeseries looks like the yellow(?) trace on that same plot.
Opened FRS Ticket 13570 to track that H1 BRS EX ethernet connector at interface box needs to be repaired.
Is it safe to transition from WINDY NO BRSX back to regular WINDY while in NOMINAL LOW NOISE? (Or do we have to wait until we are not locked to make this transition?)
The transition is handled by the SEI_CONF guardian, and is very similar to making the transition to the earthquake state, and does not affect the observation bit. If anything, putting the BRSX back into the loop should make the IFO quieter, assuming the BRS has calmed down.
Looking at minute trends of the sensor correction outputs for EX and EY for the last day, we could have transitioned back about 5pm local last night, first plot.
This is inspite of the fact that the BRSX was still not totally settled, the DC position is still slowly settling down, second plot.
And, the BRSX RY out still had something like a 5000 nrad offset (third image), it was moving slowly enough to not affect the sensor correction signal.
Ah, My Bad.
Could this be the source of my woes with locking after the h1boot1 recovery?