We now have a guardian for the squeezer SHG locking loop which seems to be working fine.  It is located in sqz/h1/guardian In order to run it Dave had to add the sqz guardian directories to the list of places where the guardian machine checks for code.  

It is a very simple guardian, with 3 states, down, lock, and locked.  

It currently uses the transmitted IR power through the SHG to determine if the cavity is locked. Once we have a calibrated green diode (which Terry is working on as I'm writing), we can use that instead. 

There is some basic error checking but much more could be added. 

It locks the cavity by toggling the state of the first boost.  If this doesn't work, it starts a scan of the cavity using the slow output offset, and toggles the boost at each step of the way.  The step size and speed of the scan can be adjusted, but it seems to lock the cavity within about a second with the current settings.