Reports until 13:24, Friday 17 January 2020
H1 SUS
cheryl.vorvick@LIGO.ORG - posted 13:24, Friday 17 January 2020 - last comment - 08:26, Saturday 18 January 2020(54560)
ETMY mode 20 positive gain is ringing the mode up every relock, setting gain to zero in guardian

I noticed that at every relock since ETMY mode 20 range up on Tuesday, the positive gain of 0.5 has been ringing up this mode.  Plot attached shows the mode being rung up by the positive gain on the last 3 relocks.  No idea, yet, why this mode needs a gain that is oposite of what was working before.

I talked to Rahul and Sheila, and since we're out of Obesrve, I'm going to change the guardian to set to gain to zero, and reload the violin guadian only, before returning to Observe, so that when we relock, this mode will not be damped.  Not damping mode 20 has worked to prevent it from ringing up more, since Tuesday.

lscparams updated for ETMY mode 20, gain set to 0, checked in, waiting for commissioning to complete to load.

- Cheryl, Rahul

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cheryl.vorvick@LIGO.ORG - 13:54, Friday 17 January 2020 (54561)

Tested ETMY mode 20 damping at a of -0.5, which damped but effected mode13, tested gain at -0.2, which works, effects mode 18, but not by much, gain is set back to zero.  Guardian code loaded.