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Message ID: 2159     Entry time: Fri Mar 30 17:34:52 2018
Author: awade 
Type: DailyProgress 
Category: Other 
Subject: Sign flip on Laser slow control PID parameters 

I've been updating the IOC .db files to include new soft channels that break the refcav shield heaters into a common heating and differential heating component.  This should improve actuation on the cavity length by symmetrizing the temperature actuation.

However, after a few channel renamings and restarts to the IOC process I've found that the cavity auto lockers were no longer achieving lock.  On closer inspection it turns out that the PIDLocker on the laser slow frequency controls was switched to the beta version of the script which has a sign flip on the actuation direction. Autolockers were working fine but the PID was switching on and promptly unlocking the cavities by driving in the wrong direction.  I've flipped the sign of all the laser slow controls Kp, Ki and Kd.  The problem is fixed and cavities are now auto locking themselves again.

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