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Reports until 21:15, Friday 31 January 2020
H1 SQZ
patrick.thomas@LIGO.ORG - posted 21:15, Friday 31 January 2020 - last comment - 14:07, Monday 03 February 2020(54838)
Unexpected SDF difference after squeezer takes us out of observing
05:00 UTC Squeezer takes us out of observing.

The SQZ_MANAGER node seems to say it is stalled.

I hit INIT on the SQZ_MANAGER node.

The SQZ_MANAGER guardian state makes it back to SQUEEZING.

There is an SDF difference (attached). I accepted it.

05:04 UTC Back to observing.
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patrick.thomas@LIGO.ORG - 22:01, Friday 31 January 2020 (54839)
Happened again, but no SDF difference this time. See attached screenshot.
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sheila.dwyer@LIGO.ORG - 14:07, Monday 03 February 2020 (54872)

Keita, Sheila

The reason the SQZ_MANAGER was stalled, and didn't relock the squeezer, is left over from a mistake I made on Thursday.  

I commented out the line @unstall_nodes decorator in ISC_LOCK Nominal_low_noise, which is a work around for a problem with the new lose management.  If I don't comment out this line, even while the SQZ_MANAGER is in auto mode, ISC_LOCK will take control of it and re-inject squeezing into the IFO, messing up whatever measurements are going on.  Part of this that I don't understand is that it takes several minutes for this to happen.  I usually take this linke out and put it back into the guardian when I'm done with the test, but forgot this time.  We've talked about the problem with Jamie, he says that there is some kind of solution coming, perhaps making the loose management optional so that we can turn it off. 

The SDF diff that Patrick accepted here is that the CLF ISS is on, which it should always be.  It has been off since the observing stretch which we had without squeezing on Thursday.  This is also my mistake, we accepted many SDFs to go to observing without squeezing on Thursday, and this one I didn't undo correctly.  

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