[Jenne, Daniel, Ed, JeffB]
While recovering the IFO, Jeff and I could not engage the WFS centering for the AS WFS which needs to happen for us to engage the DRMI ASC. After some confusion about what the problem was, Daniel suggested that probably the high voltage supply for the fast shutter was off. We went to the CER mezzanine, and indeed both the OMC PZT and the fast shutter's HV were both off. This likely happened as a result of some vac/Beckhoff restarts that happened today, which probably triggered the interlock that shuts off the HV when the pressure in HAM6 is too high. As soon as we turned on the high voltage, everything was good again.
So, on the one hand, this is not a situation we expect to run into very often. On the other hand, we should probably put a test into the DIAG_MAIN guardian indicating that the HV is off so that we don't spend an hour confused again. There is a test in DIAG_MAIN for the OMC PZT's HV, but that doesn't start looking until we're close to DC readout. We could just use this, since both HVs will be turned off at the same time.
The fast shutter test that checks that the shutter fires by look at the GS 13s at the time of a lockloss where we had more than 14kW gave us one false alarm tonight.
(It correctly reported that the shutter did not fire in a lockloss where the circulating power dropped). Not enough of the power was sent to the AS port for H1:SYS-MOTION_C_SHUTTER_G_TRIGGER_VOLTS to get close to its threshold of 2 Volts.
We probably want to increase this threshold to avoid false alarms so people don't get in the habit of ignoring the warning. For now I have increased it to 25kW, and committed to the SVN.