Georgia, Koji, Jeff K, Sheila

We made a couple of small updates to the OMC_LOCK guardian and omcparams:

TUNE_OFFSETS state

We had a lockloss straight after transitioning to DC readout. Looking back at the guardian log (first attachment) we see that in the TUNE_OFFSETS state, where the guardian measures RF DARM to OMC transfer function and sets some gains to match them, the transfer function failed and some channels are set to nan. I'm not sure yet what IFO conditions created this condition, but we added an error flag to the TUNE_OFFSETS state to prevent the OMC from proceeding to READY_FOR_HANDOFF if the TF fails.

FIND_CARRIER

The OMC guardian has been having trouble finding the carrier on its own in the last ~week. In FIND_CARRIER it sweeps PZT2 and looks at the DCPD's, first finding the two 45 MHz sidebands and then searching for the carrier halfway between them. The current offset on PZT2 for the carrier resonance is ~77V, and the scan sweeps from 20-80V, it looks like in our current sweep range we only see one 45 MHz sideband and the carrier. The second attached photo shows the data for two sweeps, third is zoomed into one sweep. I will reduce the starting PZT offset in omcparams so that we  sweep through both 45 MHz sidebands on the lower (~28V) carrier resonance, given past issues with 9MHz higher order modes resonant at large PZT offsets.