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
Entry  Wed May 23 13:57:11 2012, Jenne, Bureaucracy, General, 40m Meeting Action Items 
    Reply  Wed May 23 20:41:37 2012, Suresh, Bureaucracy, General, 40m Meeting Action Items: Tip-tilts : cabling and electronics  
    Reply  Thu May 24 01:17:13 2012, Den, Update, CDS, PMC autolocker 
       Reply  Sun Jun 24 23:42:31 2012, yuta, Update, Computer Scripts / Programs, PMC locker 
          Reply  Mon Jun 25 21:54:52 2012, Den, Update, Computer Scripts / Programs, PMC locker 
             Reply  Tue Jun 26 00:52:18 2012, yuta, Update, Computer Scripts / Programs, PMC locker 
                Reply  Thu Sep 19 18:48:24 2013, rana, Update, Computer Scripts / Programs, PMC locker pmc.png
                   Reply  Thu Sep 19 21:15:44 2013, rana, Update, Computer Scripts / Programs, PMC locker Untitled.pdf
Message ID: 9141     Entry time: Thu Sep 19 18:48:24 2013     In reply to: 6873     Reply to this: 9142
Author: rana 
Type: Update 
Category: Computer Scripts / Programs 
Subject: PMC locker 

 In May of 2013 Den wrote a PMC Autolocker because he ignored / didn't want to read anyone else's code. Later that year Yuta also wrote another one from scratch for the same reasons.

I tried to use both today, but neither one runs. Yuta's one doesn't run because he was using a bunch of private yuta library stuff in the yuta directory. That kind of programming style is pretty useless for us since it never works after some time.

So I re-activated and tested the PMCAutolock bash script (it is actually a symbolic link called "PMCAutolock" which points to AutoLock.sh). These scripts are all basically the same:

They turn off the loop (or turn down the gain) and then scan the PZT, look for a resonance, and then activate the loop.

One problem with the logic has been that turning off the loop makes the gain so low that the peak flashes by too fast. But leaving the loop ON and just sweeping with the gain turned down to -10 dB is also not good. That only reduces the UGF from 1 kHz to ~100 Hz. What we want is more like a 10 Hz UGF while scanning the length. SO, I edited the script to turn down the modulation depth on the EOM by that factor. After acquiring lock, it returns all settings to the nominal levels as defined on the PSL_SETTINGS screen.

I've tested it a few times and it seems to work OK. You can run it from the yellow shabang button on the PMC screen.

I also changed the .bashrc aliases for the MEDM command so that if you type medm_good at the command line you get MEDM screens with scalable fonts. So you can stretch the screens.

Attachment 1: pmc.png  91 kB  | Hide | Hide all
pmc.png
ELOG V3.1.3-