As Elenna says in 65718 we've seen a 3.3Hz ring up when we sit at higher power without reducing the CSOFT bandwidth.  Marie emailed us to remind us that LLO solved a 3.3Hz instability they saw was related to ASC as they powered up by implementing a new damping path from L2 pit to R0 P +R (FRS 11730)

We already had the path in place in the simulink model, which routes L2 PIT to R0 P + R.  I checked this morning that the LLO filters that we had in the userapps repo were up to date with what is being run at LLO, and simply copied the gains.  I attempted to recreate the measurement Anamaria posts in the second attachment to 49395, driving a pit exctiation on L2 and measuring the response in L2 P, L1 P, R0 P and R0 R.  The attached plot shows that with the damping on, the excitation shows up more in R0 P, similar in R0 roll and larger in L1 P with the damping on.  In L2 P witness the excitation shows up slightly smaller. This doesn't seem as convinving that the damping is working as Anamaria's plot, I would like to repeat the measurement with a higher excitation.  

I've only turned this on for the ITMs, since that is how LLO does that.  I'm not sure if we will need this path engaged on the ETMs.