WP 6235:
We added a feedforward path from the DBB QPDs to the LSC DARM or LSC REFL_DC_BIAS. There are new filters name H1:PSL-DBB_FF_QPD1X, 2X, 1Y and 2Y, followed by a matrix H1:PSL-DBB_FF_QPDMAT. Then the signal is sent to the LSC model, where there is a filter module H1:LSC-JITTERFF followed by an output matrix H1:LSC-JITTERFF_MAT. The signal is then added to either the DARM error point, or sent to the REFL_DC_BIAS output.
In the LSC model the temporary third loop ISS which is now defunct was deleted and the EXTRA_AO_3 path restored. The hardware was also disconnected.
We also noticed that the REFL_DC_ERR and COMM_A_RF_ERR paths were swapped. The same was true for REFL_A_RF9_ERR and REFLAIR_A_RF9_ERR. They should be correct now. The REFL_DC_BIAS output is directly connected to the REF_DC_ERR input. If we need dewhitening we should switch this to the excitation input.
WP 6239:
The model part for the second loop ISS QPD was changed to one which supports the whitening filter switching.