The green slow and tidal servos have been engaged. This is done through the arm guardian which in turn select a corresponding state from the ALS auto-locker. These states are "End Locked", "Slow Engaged", "Transition" and "Red Locked". With "End Locked" neither the slow nor tidal servo are engaged. With "Slow Engaged" they are both on, tidal feedback only in "Transition" and tidal and common mode feedback in "Red Locked". These three new feedback paths use the new integrator filter module. When the green PDH is not locked, the integrators are bled off.
The feedback topology is as follows:
The "Red Locked" state triggeres on the transmitted red power. Once in this state, it no longer matters whether green is locked. It can only transition back, when the red lock is lost.
Here is a 1.33 hour trend plot. Both the arm and tidal error signals stay within a few µm of zero, whereas the HEPI drive slow ramps upwards to 8 µm. With the WFS enagaged the arm power is solid. (The jump towards the end is due to some stray light from the x arm.)
Here is a 21h trend plot of both green arms. WFS & tidal get a thumbs up.