40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Message ID: 8460     Entry time: Thu Apr 18 02:51:52 2013
Author: Den 
Type: Update 
Category: PSL 
Subject: FSS slow servo 

Today Rana pointed out that our FSS slow servo is malfunctioning. It has been for a while that our laser temperature control voltage drifted from 0 to 10.

I looked at FSSSlowServo script that runs at op340m and controls the servo. Script disables the servo when MC transmission is less then FSS_LOCKEDLEVEL. But his value was set to 0.2 probably till reference cavity time.

This means that slow servo was not disabled when MC was unlocked. I changed this value to 7000.

Also I increased integral gain from 0.0350 to 0.215 such that fast control is always in the range 4.5 - 5.5

ELOG V3.1.3-