J. Kissel, B. Weaver

While down in the weeds of FSS oscillations and ALS issues, Betsy and I quickly looked at all of the Binary IO states of suspension which are toggled in the LOWNOISE_COIL_DRIVERS ISC_LOCK state -- i.e. the high-level acquisition state at which Corey reports regularly losing lock last night (see LHO aLOG 51288). We looked at the read-backs (e.g. H1:SUS-ITMX_BIO_L2_MON), and also toggled the state from its regular acquisition state to its low noise state, which are the following:
in LOWNOISE_COIL_DRIVERS:
            optics   = ['PRM', 'PR2', 'SRM', 'SR2', 'BS', 'ETMY', 'ETMX', 'ITMY', 'ITMX']
            stage    = ['M3',  'M3',  'M3',  'M3',  'M2', 'L2',   'L2',   'L2',   'L2']
            newState = [ 3,     3,     3,     3,     3,    1,      1,      1,      1]

At times in the past, we've seen that either
    - passively, the readbacks don't match the requested state for one or two of the coil drivers
    - actively, when switched, the readbacks don't respond, or don't respond as expected.
(see e.g. LHO aLOGs 40517, 39880, 39539)

We see neither of these things -- all readbacks and switching behave as expected.