[Daniel, Jenne]
At 17:06 local, so 00:06 on 27 Mar 2019 UTC, we turned off by hand the corner station ALS VCOs (COMM VCO, COMM FDD, DIFF VCO, DIFF FDD), using the new relays mentioned in alogs 47894 and 47893.
I have also added turning them on and off to the main ISC_LOCK guardian. When we get to PARK_ALS_VCOs (no longer using ALS for any lock) the VCOs and FDDs will now be turned off. The PREP_FOR_LOCKING state will turn them back on. Note that the channels are "disable" switches rather than our more usual "enable" switches, so to turn off the VCO, you must set the bit to 1. The MEDM screens just say on/off, so it's clear, but the guardian uses the numerical values, which is why I make note of it.
DetChar: It would be helpful if you could have a look at tonight's lock and see if the whistle situation is improved. Hopefully it will be!
Thanks for looking at this. We'll do a slow sweep of the IMC VCO frequency over a longer range to hopefully find a good place.
While looking at the history of the situation, I see that the reboots due to the new on/off switches that happened on Tuesday seem to have removed the offset of the setpoint that we'd been using since Daniel set it on March 12th (alog 47470).