First, I implemented OMMT2T centering loop to OMMT1, which is reported in klog23728.
Then, We tested ADSs of OMMT2 and OSTM for fine alignment to OMC.
Since the OMC QPD loop is currently stable (it was not stable during O3 due to glitch problems), we feedback ADS signals to the setpoint of QPD loops.
Followings are the detail of setting of ADSs:
Dither frequency: 15 Hz, 16 Hz, 17 Hz, and 18 Hz for OMMT2P, OMMT2Y, OSTMY, and OSTMP, respectively.
Dither amplitude: 200 cnts for pitch and 600 cnts for yaw.
INF filter: FM1 (BandPass filter)
OUTF filter: FM1 (LP1), FM2 (comb15), FM3 (comb1), FM9 (integrator)
Figure 1 shows the time series of ADS feedback and OMC output.
Transmission power increases from 34 to 50, and ADSs seem working well.
I implemnted the ADSs in INITIAL_ALIGNMENT guardian but maybe it is better to move it some other guardian like OMC_ASC.
During the work, OMC_ASC guardian moved OMMT1 and kicked the suspension because it was used for OMMT2T QPD centering.
Since OMMT1 doesn't use OMC alignment, I removed the request to OMMT1 from OMC_ASC guardian not to conflict the alignment control.
Also, we faced some bugs of OMC_ASC guardian.
Figure 2 shows the log around the bug.
It seems new thread is called withouut killing the existing thread, so it needs to be fixed.