After Peter King brought back the laser, we relocked the interferometer.
We had to increase the OMC scan range ( omcparams.scan_vramp ) from 40 to 60 for the guardian to find both sidebands.
Then we again lost it twice during the COIL_DRIVER swtiching because of a 2Hz CSOFT signal (pitch and yaw) ringing up. Lockloss plots of both locks are attached.
Next we switched back to ther old COILD_DRIVER_SLOW switching. Interesting, we still had problems once we stated switching test masses (ETMY - the first one tried). All the corner optics switched without problems (Actually, SRM and SR2 had 0 seconds matrix ramp time, and still were fine. I set it to 1 sec for now - we should speed that switching up. )
In a second attempt I tried only switching ETMY by itself - with all top mass relief loops off (because the high BW offloading was one of the things we changed). still no luck - same 2Hz instability.
Still something changed with the test masses - it is not just the switching script.
A large earthquake spopped further work. I left the slow COIL_DRIVER_SLOW state as a parallel path in the Guardian for debugging. Also It currently only switches PRM, PR2, SRM, SR2, BS.
Kiwamu will try to do some ISS work with the IMC during the quake.
Is the coil driver switching still trying to go from state 2 (highest range) to state 3 (lowest range)? If so, you might try going from state 2 to state 1 (ACQ off, LP off), in case the lock loss problems come from lack of range.