Previously (90441), Tom, Ibrahim, and I had found out that the QOSEM coil drivers were wired opposite as compared to other OSEMs. To compensate for this at the time (since we were attempting to use damping), we had swapped the signs of the damping gains. But we had only swapped those gains, meaning that other actuation coming through the TEST or OPTICALIGN filter banks was still pushing the coil drivers the opposite way from expected. Today we finally decided to fix it to reduce confusion wrt the direction the BS was moving when offsets were put in (offsets were moving the BS in the opposite direction than expected).
To do this all I did was put the M1 DAMP filter gains back (before, after) to being negative and then swapped the signs of the gains in M1 COILOUTF (before, after). To put the beamsplitter back with the OPTICALIGN offsets that it had before, I then swapped the sign of each offset.
I will update the SUS Sign Conventions document to mention that the QOSEMs require the opposite COILOUTF signs from nominal.
So now EVERY BBSS OPTICALIGN slider offset from before 2026/06/24 00:50 UTC requires the opposite sign to be recreated.
Following this sign change, we verified the following conventions for the M1 actuation :
Positive offset on the coil ouptut filterbanks corresponds to positive qosem signal on M1(figure 1)
Positive offset on the cartesian basis (test filterbanks) corresponds to positive cartesian signal on M1 (figure 3)
Figure 2 and Figure 4 show the dc cross couplings for the local and cartesian basis drive, as as reference for the on-going xcoupling investigation.
The two scripts to make those plots were saved in the svn under /opt/rtcds/userapps/trunk/sus/h1/scripts
push_pull_bs.py
push_pull_bs_cartesian.py
