[Stefan, Kiwamu]

  Today Stefan reminded me that the WFS RTS library parts for its DC signal was updated in July 30th (see LLO alog 8061) and we haven't applied it at all in LHO. This update was for fixing the numbering of the four DC segments to match with that of the RF segments. Before appplying this updates, we wanted to make sure that this is the right thing to do. So for the reason we did a brief check on the existing WFSs, namely IMC WFSs on ITO2L. We intentionally misaligned the IMC REFL such that it hits only one of the four segments and did a block-and-unblock power modulation by hand to identify which segment responds. We went through all four segments on both WFS_A and WFS_B. Indeed the DC segments were in a wrong order of {4,3,2,1} while it is {1,2,3,4} in the RF segments. Indeed we need to correct it in the IMC realitme model although we haven't corrected it yet.

 Looking at the l1asc model which uses the updated WFS library, we noticed that the labels of the tags associated with the DC library parts were incorrect. We probably need to talk to poeple in LLO to make sure that the update was done in a proper way.