jenne.driggers@LIGO.ORG - posted 15:51, Tuesday 17 July 2018 - last comment - 16:01, Tuesday 17 July 2018(42942)
L2, L3 stages of quads not actuating after reboots today
I am finding that I am unable to actuate the L2 or L3 stages of ITMX or ETMX. I have not yet checked the Yarm quads as others are using them right now. But, all 4 quad models were rebooted today as a fix for ticket https://services.ligo-la.caltech.edu/FRS/show_bug.cgi?id=11066. The BIO settings look fine. Putting an offset in one of the coil output filter banks sends signal through the MASTER_OUT channel to the DAC, and from the IOP CDS screen, it looks like the DAC is in fact sending the signal out. But, the current monitors don't see a response, and the optic doesn't actually move. I can actuate on the upper 2 stages of the quads just fine.
This has been filed as FRS 11099. DaveB isn't sure what could cause this, so JeffK is currently in the CER to see if there is anything obviously wrong with the ITM coil drivers.
Just kidding. After looking at it again with Jeff, there isn't a problem. The current monitor responses are just really a lot smaller than I had thought I remembered, and 21Hz is too high a frequency to see in the optical levers, even if I drive near max range on the lowest stage of the ETM.
Anyhow, not a fault.