When LLO had the RTD problem, they saw that their excess noise went away when the grounded all ESD cables at the end station with the bad RTD.  We wanted to check if we could have a similar electronics noise coupling that involved the ESD cables, so a few weeks ago we locked with the ITM cables grounded.  Today I locked with the ETMY ESD grounded, and saw no change in the noise.

Details:

In order to ground the end station ESDs, we needed to be able to transition DARM to the ITM during the acquisition sequence so that we could swap the one energized ETM ESD to the low noise mode. 

Attached is a script that was (mostly) used instead of the LOWNOISE_ESD_ETMY guardian state.  While this was run a few lines at a time for debugging this time, I think it should be ready to be used again if needed.

We were locked in low noise starting around 22:24:30 UTC Sept 2nd.  The lock only lasted about 20 minutes because we use the ETMY ESD to damp two PIs which ring up with it grounded.