The end station laser locking ran away when the reference cavity was unlocked earlier today. When PSL tries to relock the reference cavity it searches for a resanance by changing the PSL frequency substabtially. The end station lasers try to follow but eventually lost it and went into lala land.
In the past this didn't happen because the end station laser locking would automatically pause, when the reference cavity was unlocked. When we changed the PSL fiber pick-off, we moved the monitor PD as well and it now just monitors the power after the PMC. The PD after the reference cavity is still there, so we should conect it to a spare channel in the auxiliary signals concentrator 3.
The PSL reference cavity transmission PD was hooked up to a spare channel and the software was updated accordingly.
Channel names are H1:PSL-REFCAV_TRANS_DC_POWER and similar.
The normalized current of this new PD channel is sent to the ALS and SQZ lasers for determining the locking conditions. The threshold has been set to 0.3. So, when the refernce cavity looses lock, these laser locking servos will now pause.