The ITMX Yaw oplev damping is now working, with feedback to the PUM only. 

I am using a verry similar loop to the one for ETMX, but this time I had to add a low pass at 5 Hz to avoid saturating the DAC at high frequencies.  I am using a gain of 1 and the first three filter modules in ITMX_L2_OLDAMP.  The open loop gain measurement and spectra showing the performance are attached. 

With these three opLev damping (ETMX PIT, YAW and ITMX YAW) loops engaged the cavity lock is stable. 

We need a sign flip in the COMM slow path to lock, this must be because of the sign flip in MC2 on tuesday morning. 

COMM was locking stably for a while.  I tried to make a comparison of the noise with OpLev damping on and off, but the measurement is not verry repeatable, so it was hard to make any conclusions. 

I am going to leave COMM handed off over night, with the three opLev damping loops running, so there should be IR in the arm cavity for part of the night.