J. Kissel
FRS Ticket 5058

After Betsy and Travis replaced the physical OSEM itself yesterday, I tried using the OSEM to drive the suspension. Still no dice. 

See attachments for proof.
(1) An actuation range test (similar to that from LHO aLOG 13256), where the COILOUTF bank OFFSETs are used to drive the complete DAC range (~100k cts) and the response is monitored in the corresponding OSEMs. While LL, UR, and LR show plenty of signs of life -- still nothing from UL.
(2) An awggui, 1.45 Hz, sine-wave excitation into the UL and LL COILOUTF banks, where again, the response is monitored by the corresponding OSEM. While UL excitation shows nothing, an LL excitation shows up in both the UL and LL sensors.
(3) "Traditional" health check of an M2 to M2 suite of transfer functions (hoping for similar confirmation of weird stuff in LHO aLOG 13262). Not nearly as obvious that things are weird from the individual OSEM traces, but one can clearly see L and P resonances coupling in the Y transfer function, when one definitely should not -- especially since the SUS has been confirmed to be free via M1-to-M1 transfer functions (see LHO aLOG 39265).

Notes: 
- I restored the EUL2OSEM matrix to it's nominal, fully, functional HSTS values (the L2UL and L2LR elements had been zeroed, and the L2LL and L2UR elements had been doubled, so as to avoid using UL in a longitudinal excitation, but to still get an excitation.)
- For these measurements, I changed the coil driver configuration from its lowest noise configuration (state 3) to its highest range configuration (state 2).