Guardian returned True in the middle of main state?
From LHO control room chat: https://chat.ligo.org/ligo/pl/84zwqfdd83r4dfki4qwtz8bj3w
Sheila: @Jameson Rollins @Thomas Shaffer Here is a screenshot of the OMC gaurdian, when it gets a redirect request while in the OMC_LSC_ON state. It does some but not all of the steps in OMC_LSC_ON, but then returns the next state, OMC_LOCKED before completing main.
1:09 PM
So the IFO transitioned to DC readout even though the OMC wasn't locked. We only noticed this because by luck the OMC was staying close enough to on resonance to keep the IFO locked.
Jenne: One thing I wonder (haven't figured out yet) is if ISC_LOCK was requesting the OMC_LOCK to DOWN, but then OMC_LOCK was able to jump from halfway through the main state it was in to the next in sequence, rather than to DOWN.
Sheila: yeah, I think there's no situation where it should have returned true halfway through main. And it has to return true to move onto the next state in the graph. But there might be a bug in the way the redirect is handled that allows this to happen?