camilla.compton@LIGO.ORG - posted 09:11, Thursday 16 September 2021 - last comment - 10:59, Friday 17 September 2021(59930)
HAM7 SQZ VOPO Status- Cabling Complete
All cables are now routed over the VOPO, see alog 59929 for deatails and photos. We plan to re-balance the OPOS today (don't need laser hazard) and if all goes well install the fibers tomorrow. These fibers are extremely delicate so after they are installed, extra care will need to be taken while working in HAM7.
Something is wrong with OPOS OSEMs as of now, though we can actuate and read them.
If you give a big offset to COILOUTF filter one by one, corresponding OSEMINF goes in the opposite sign for all OSEMs except for H3 (1st attachment).
Sign of Euler based TF (e.g. H1:SUS-OPO_M1_TEST_T_EXC to H1:SUS-OPO_M1_DAMP_T_IN1_DQ) is flipped from the past measurements for all DOFs except T (2nd attachment shows T, 3rd shows Y as an example). Dtt templates are saved in /ligo/svncommon/SusSVN/sus/trunk/OPOS/H1/OPO/SAGM1/Data as
2021-09-16_2129_H1SUSOPO_M1_WhiteNoise_L_0p2to50Hz.xml
2021-09-16_2129_H1SUSOPO_M1_WhiteNoise_P_0p2to50Hz.xml
2021-09-16_2129_H1SUSOPO_M1_WhiteNoise_R_0p2to50Hz.xml
2021-09-16_2129_H1SUSOPO_M1_WhiteNoise_T_0p2to50Hz.xml
2021-09-16_2129_H1SUSOPO_M1_WhiteNoise_V_0p2to50Hz.xml
2021-09-16_2129_H1SUSOPO_M1_WhiteNoise_Y_0p2to50Hz.xml
but don't get seroius about these, probably there are problem in hardware or some gains or filters.
Also, we haven't centered OSEMs yet, that needs to be done tomorrow (but centering OSEMs don't change the sign of OSEM-based response shown in the 1st attachment).
The problem that Ketia notes above seems just like the one that Jeff describes in 2018: 41256
There Jeff says he flipped the sign on H3 COILOUTF. Trending these channels, the sign on all the other COILOUTF was -1 until a period of missing data from August 17th to 25th, which was probably the model change. Since the WD is tripped right now I flipped the sign on the other 5 coiloutF and accepted this in SDF. Since we apparently lost settings and SDF stuff in the model change we may encounter other similar problems.