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Entry  Tue Jun 22 14:35:40 2021, aaron, shruti, DailyProgress, Control System, slow temperature control 7x
    Reply  Wed Jun 23 17:53:21 2021, aaron, DailyProgress, Control System, slow temperature control 
       Reply  Thu Jun 24 12:26:56 2021, shruti, DailyProgress, Control System, slow temperature control 
          Reply  Thu Jun 24 14:37:12 2021, aaron, DailyProgress, Control System, slow temperature control, more transfer functions 
             Reply  Mon Jun 28 10:12:28 2021, shruti, DailyProgress, Control System, glitches, transfer function glitches.pngOLTF.pdfSetup.pdfData.zip
                Reply  Mon Jun 28 13:16:07 2021, aaron, DailyProgress, Control System, glitches 
                   Reply  Tue Jun 29 08:53:02 2021, Chris, HowTo, Control System, acquiring slow channels 
Message ID: 2766     Entry time: Mon Jun 28 10:12:28 2021     In reply to: 2765     Reply to this: 2767
Author: shruti 
Type: DailyProgress 
Category: Control System 
Subject: glitches, transfer function 

The glitches seem to come from the slow controls output and temporarily result in an actuation voltage of +-10 V even when the limit for that channel was set to +-2 V in the PID script. This triggers the 'WIN' light and a beep from the ITC 502 while also losing the lock.

Aaron and I also had observed this last week.

 

[shruti, chris]

We were able to measure the loop transfer functions with the latest settings of KI=0.5 and PDH_CTL offset=2000cts on the slow control without being affected by the glitches too much. Chris also set up all the slow control channels so that they can be viewed with ndscope. In this we could also see that the transmission monitor sometimes glitched but the loop remained locked.

 

Attachment 2:

Updated measurement similar to elog 2759

Attachment 1: glitches.png  126 kB  Uploaded Mon Jun 28 11:12:44 2021  | Hide | Hide all
glitches.png
Attachment 2: OLTF.pdf  84 kB  Uploaded Tue Jun 29 10:50:27 2021  | Hide | Hide all
OLTF.pdf
Attachment 3: Setup.pdf  1.652 MB  Uploaded Tue Jun 29 11:09:56 2021  | Hide | Hide all
Setup.pdf
Attachment 4: Data.zip  7.726 MB  Uploaded Tue Jun 29 11:10:33 2021
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