Again inspired by Zach's bash autolocker, I've written a python autolocker for the south reference cavity. If the cavity loses lock, it turns off the PID loop so that the temperature does not run away to the rails. It then checks that the PMC transmission is high and proceeds to slowly ramp the laser temperature between 7.43 V and 7.50 V.
Note: the aforementioned voltage values only work because the refcav is not heated, and hence the resonance always occurs in roughly the same place (between 7.45 V and 7.48 V, depending on the day). This simple search algorithm is therefore not, not a permanent solution for autolocking the refcav once the heaters are working. For posterity, here are the other values currently hard-coded into the autolocker:
The autolocker can be invoked via python srefcavauto.py on controls@fb2.
Since autolocker is coded to do nothing unless the PMC transmission is high, it is best run in conjunction with the PMC autolocker (invoked via python pmcauto.py). It doesn't matter which autolocker you start first.
Special bonus settings: the common gain on the TTFSS is 404 clicks, the fast gain is 426 clicks, and the offset is 967 clicks. Tara pointed out that the frequency loop would catch lock easier if the gain settings were around these low values rather that what they were previously (~600).