We wanted to check if the value of the H1:LSC-IFO_TRIG_INMON lower threshold was possibly too low. If once the detector lost lock the IFO_TRIG_INMON channel took too long to reach its minimum trigger value (325), the violin damping gains would stay on too long and could be the cause of the violins ringing up so high, which started happening after the June 27 maintainance (71063).

(Uploads 1+2) I took the channel H1:ASC-AS_A_DC_NSUM_OUT16 to pinpoint when the detector lost lock, and plotted it alongside H1:LSC-IFO_TRIG_INMON. When the H1:LSC-IFO_TRIG_INMON channel value drops below 325, the damping for L2 and L3 should turn off. Comparing a lock loss before June 27 to after, both of which were from long lock stretches, it looks like for both times (and for the other lock losses I looked at), the time between the lock loss occuring and the damping turning off was about the same, between 1-1.5 seconds.

(Upload 3) There is also a clear difference pre- and post- June 27th in the amount of gain used to damp the violins.