J. Betzwieser, B. Bland, J. Kissel

While trying to turn on H2SUSFMY, post-cartridge install, we noticed two problems with the sensor signals coming in from the OSEMs.
(1) On the input side, the raw ADC channels (H2:SUS-FMY_M1_OSEMINF_*_IN1_DQ) were very small, and oscillating around zero (say, 0 +/- 5 cts).
(2) Just after the compensation filters, the signals (H2:SUS-FMY_M1_OSEMINF_*_OUT_DQ) were large (say, 120000 +/- 5 cts).

The first problem turned out to be that the H2SUSFMY Rack electronics were not powered on. Once turned on, we found a different problem: signals were all 100 +/- 2000 cts, where these channels should never go negative. If centered and the suspension is free the signals should be +15000 +/- 1000. This is still under investigation, stay tuned for further results.

The second problem turned out to be a bug in the OSEMINF deWhite, sat amp compensation filters (installed in FM1 of the H2:SUS-FMY_M1_OSEMINF_* filter banks). These filters were installed with the matlab easyquack/automatic compensation filter generator software suite called using,
${SusSVN}/sus/trunk/Common/MatlabTools/prepare.m
some time ago to test out the program (last time I was at LHO, between Nov 13 and Nov 20, 2011; I didn't aLOG it ). Since, we've discovered a bug in the generator that adds a factor ~6 DC gain to these filters, when they should have a DC gain of 1.

Joe is aware of the bug, and currently fixing it, but in the mean time, in the interest of expediency I've just fixed the bug "by hand," editing the filter text file in foton. These fixed filters have been loaded, and the OSEMINF_*_OUT signals appear as expected (baring in mind the first problem is still there).

Once Joe fixes prepare, we'll try running it again (and I'll aLOG it this time!).