We were locked last night at 50 W for ~2.5 hours and lost lock from an ITMX 15522 Hz PI. This is a known PI seen months ago; I had purposefully left damping settings off to see if it rang up. See first attachment showing lockloss. 

This afternoon we were locked at 50 W for ~2 hours and I let the mode ring up so I could demonstrate successful damping. See second attachment showing damping. 

All PIs that were previously observed have now been seen and damped post OMC vent. We have 5 PIs at 50 W  (at least up to ~3 hour locks): ITMX 15520 Hz; ETMX 15541 Hz; ETMY 15542 Hz, 15009 Hz, 18041 Hz (aliased from 47495 Hz).  All are successfully damped via the guardian and have had their damping phase and gain optimized.