J. Kissel
I've increased the actuation delay before the sum of the the RESIDUAL (sensing) and CTRL (actuation) paths in the CAL-CS reproduction of H1:CAL-CS_DARM_DELTAL_EXTERNAL from four 16 [kHz] clock cycles (244 [us]) to seven 16 [kHz] clock cycles (427 [us]). This is done by changing the H1:CAL-CS_DARM_CTRL_DELAY_CYCLES EPICs record. The change is motived in LHO aLOG 21746. Recall this only affects the reproduction of the DARM displacement signal H1:CAL-CS_DARM_DELTAL_EXTERNAL (and therefore its ASD projected on the wall). I attach screenshots of the before and after. Note that the ASDs were taken ~30 minutes apart, so I don't expect the detailed structure to be the same. However, the change in phase at the sensing / actuation cross over causes overall shap change in the bucket. Also note that the transfer function used to remove the systematics from the DELTAL EXTERNAL channel will now have to be updated (documented in LHO aLOG 20481), to avoid double counting the high frequency affects. In the attached ASD, those corrections have *not* been changed, so we are likely double counting the corrections. More on that after I reconcile what Kiwamu had done and what Peter suggests.
I've captured the updated setting in both the OBSERVE.snap and SAFE.snap SDF files, and committed each to the repository.