Trying to understand what is going in these last days, I noticed that many signals from F0 of IB show a very high increase of motion, on some DOF more than others, with respect to two days ago. The change of regime looks relatively fast; the bad weather can have an impact but it looks unlikely (to me at least) that all of this can be attributed to wind and useism.
The problem on IB IP control is really huge, with huge side effect on INJ alignment and beam stability in the ITF. In this conditions, enormous red flags should appear in the DMS, at least for three different subsystem. Probably we have been confused by the bad weather.
The problem could come from IB accelerometer, but to say it for sure some check is needed.
Now the situation is relatively quiet and the ITF can stay locked, but the problem has not totally disappeared. Normally it will be back and it is better to do something tomorrow.
The problem was some extra noise on ACC_H1, it was back after a relatively quiet period and it was correctly patched by Fabio, moving the IB_IP control from Inertial Damping to Position Control.
Today, in the early afternoon, some test have been done by experts on ACC control configuration. At that time, ACC_H1 was quite noisy. At the end of the test the standard configuration was restored, but the noise was not there anymore. After three hours of good data, I decided to re-activate the inertial damping.
