We were stymied tonight by a problem which began late this afternoon. The MC would periodically go angularly unstable, breaking lock and tripping the MC2 watchdogs. Suspicion fell naturally upon McWFS.
Eventually I traced the problem to the MC3 SIDE damping, which appeared to not work--it wouldn't actually damp, and the Vmon values did not correspond to the SDSEN outputs. Suspicion fell on the coil driver.
Looking at the LEMO monitors on the MC3 coil driver, with the damping engaged, showed clear bit resolution at the 100mV level, indicating a digital/DAC problem. Rebooting c1sosvme, which acquires all the OSEM sensor signals and actually does the side damping, resolved the issue.