Vicky, Sheila, Camilla
While in HAM6, Sheila noticed they;d lost their SQZ beam. Vicky found that the SQZ_OPO_LR guardian had unlocked but not realized it as the variable lockloss threshold was too high. When Vicky relocked it, the beam came back fine. Plot attached showing H1:SQZ-SHUTTER_I_TRIGGER_OUT_DQ increasing but not getting over the incorrect lockoss threshold of 2800.
We edited SQZ_OPO_LR LOCKING_SEED_DITHER state to wait 15 seconds after the boosts are turned on for the OPO to be fully locked before moving to LOCKED_SEED_DITHER and calculating the lockloss threshold (p.round(cdu.avg(1,'H1:SQZ-SHUTTER_I_TRIGGER_OUT_DQ')*1.025)), rather than taking the average while the seed is still finishing locking. If the seed dither unlocks, SQZ_MANGER will relock it.
Strangely the HAM6 QPDs (e.g. OMC_A) NSUM went negative (rather than 0) when this happened, making Tony and the CDS team check there was no issues. Unsure why it did.
OPO was still not locking correctly in SEED_DITHER this morning. Sometimes incorrectly thinking it was locked and other times taking over 30 seconds to be locked and thus setting it's lockloss threshold incorrectly.
We should troubleshoot this when we are next in laser hazard.