J. Kissel After measuring charge today, I've flipped the BIAS sign on both ETMX and ETMY. In addition, I've changed the compensation scheme downstream of the BIAS flip such that signs are flipped in each quadrant's ESDOUTF bank GAIN instead of being convoluted in the the DRIVEALIGN matrix elements. This separates the functionality, compensates any angular control as well as longitudinal (though we don't send any angular control to the test mass stage at the moment), and minimizes the possibility for losing the fine-tuned DRIVEALIGN gains. Finally, I've modified the ISC guardian in such a way that it monitors the BIAS, and takes care of flipping all of the additional settings necessary to compensate for the bias change in the DOWN state. It had formerly had the DRIVEALIGN gain values hard coded, which was already bad news. Now the ESDOUTF gains (which have not been tuned / balanced as of yet) are flipped between -1 and +1; much easier to maintain. Also, I've added changing the CAL-CS settings to match as well, so the change in calibration will be taken care of as well. I would post the latest results from today's change measurements, but I've been stuck trying to get 1 second of EPICS data from NDS2 for about 4 hours now. Details ------------------ Before Flipping (to preserve my sanity, and minimize minus signs): - Moved DRIVEALIGN negative signs into the ESDOUTF bank: ETMX ETMY OLD NEW OLD NEW L2L -1 +1 -30 30 L2P -0.021 +0.021 0 0 L2Y -0.007 +0.007 0 0 and the ESDOUTF GAINs had all been positive unity, were flipped to negative unity so as to not yet actually flip the compensating sign. Then, I changed the ETMX bias sign: - Changed H1:SUS-ETMX_L3_LOCK_INBIAS from +9.5 to -9.5 [V_DAC] - (unlike before) The ISC_LOCK guardian (now) takes care of checking the sign of H1:SUS-ETMX_L3_LOCK_INBIAS, and adjusting the sign of - H1:SUS-ETMX_L3_ESDOUTF_[UL,LL,UR,LR]_GAIN from -1.000 to +1.000 (fixes the ESD stage longitudinal loop gain to match the bias sign change) - H1:SUS-ETMX_L3_ESDOUTF_LIN_FORCE_COEFF from +124518.4 to -124518.4 (fixes the linearization force coefficient to match the new bias sign) accordingly. - (like before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmx_down.snap - h1susetmx_observe.snap - h1susetmx_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. - (like before) There's no need to make any further changes in the CAL-CS epics settings, because ETMX is not used in any capacity for calibration. Followed by the ETMY bias sign: - Changed H1:SUS-ETMY_L3_LOCK_INBIAS from -9.5 to +9.5 [V_DAC] - (unlike before) The ISC_LOCK guardian (now) takes care of checking the sign of H1:SUS-ETMX_L3_LOCK_INBIAS, and adjusting the sign of - H1:SUS-ETMY_L3_ESDOUTF_[UL,LL,UR,LR]_GAIN from -1.000 to +1.000 (fixes the ESD stage longitudinal loop gain to match the bias sign change) - H1:SUS-ETMY_L3_ESDOUTF_LIN_FORCE_COEFF from -124518.4 to +124518.4 (fixes the linearization force coefficient to match the new bias sign) accordingly. - (like before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmy_down.snap - h1susetmy_observe.snap - h1susetmy_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. (This also involved *creating* a copy of the down.snap in the userapps repo, and changing the file in the target/h1susetmy/h1susetmyepics/burt/ directory to a soft link, as was already the case for the OBSERVE.snap and safe.snap) [Making sure Calibration is unaffected] - (like before) We must make sure that the CAL-CS replica of the ETMY actuation matches the SUS ETMY digital signal chain. However, because the CAL-CS model had not been restarted, and its SDF system had been kept up-to-date it did not lose the appropriate settings, so the settings for - H1:CAL-CS_DARM_FE_ETMY_L3_DRIVEALIGN_L2L_GAIN to +30.0 - H1:CAL-CS_DARM_FE_ETMY_L3_ESDOUTF_UL_GAIN to +1 - H1:CAL-CS_DARM_ANALOG_ETMY_L3_GAIN stays +1.0 - (unlike before) Again, to be consistent, I've changed the sign of the linearization force coefficient, - H1:CAL-CS_DARM_FE_ETMY_L3_ESDOUTF_LIN_FORCE_COEFF from +124518.4 to -124518.4 - (unlike before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmx_observe.snap - h1susetmx_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. (Since there is no change between the "down" and "observation" state, a "down" .snap doesn't and need not exist.)
Something is wrong with ALS DIFF, is seems to saturate constantly. Is something wrong after the bias flip?
Looks like the Linearization Force Coefficient some how got flipped back to +124518.4. We fixed the sign there, and made sure it was coded correctly in the ISC_LOCK guardian and moved on. To 50+ W no less!