I was reported that the SR2 trips due to the oplev control.
And I found that it was because the oplev signal is at the edge of the linear range without any DC control.
The control failure occurs because of drastic change of the behavior of the sensor when the oplev beam comes into the linear range.

Therefore, I adjust the initial IM orientation using the picomotor. Now the suspension can come to the ALIGNED state with the guardian.

But we should have some semi-auto alignment system using the picomotors...