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Entry  Thu May 1 03:15:03 2014, Jenne, Update, LSC, Yarm locking with CM board Yarm_CMlocking_spectra_30Apr2014_copy.pdfYarm_CMlocking_TFs_30Apr2014_copy.pdf
    Reply  Thu May 1 03:23:07 2014, ericq, Update, LSC, Yarm locking with CM board 
    Reply  Thu May 1 13:03:34 2014, Jenne, Update, LSC, MC board pulled for AC coupling 
       Reply  Thu May 1 14:45:44 2014, Jenne, Update, LSC, MC board back in IMG_1394.JPGIMG_1395.JPGIMG_1398.JPGIMG_1402.JPG
    Reply  Thu May 1 16:41:35 2014, ericq, Update, LSC, Yarm locking with CM board AOsignsSame.pdfAOsignsOpposite.pdfloopModeling.m
       Reply  Thu May 1 17:00:05 2014, rana, Update, LSC, Yarm locking with CM board 
Message ID: 9889     Entry time: Thu May 1 03:23:07 2014     In reply to: 9888
Author: ericq 
Type: Update 
Category: LSC 
Subject: Yarm locking with CM board 

Quote:

POY is going from its demod board to the CM board, and then the slow output of that is going to the POY channel of the whitening, and then on to the ADC.  So, with no AO path engaged, this is basically like regular Yarm locking.  

Just to be clear, the normal POY signals are not currently present, so the restore POY script will not result in the arm locking. POY11_I is turned off, POY11_Q is the output of the CM board, which can be used to lock the arm, as we did tonight. 

The POY digital demos angle went -56 -> 90, to get all of POY11_Q_IN1 to POY11_I_ERR

Miscellaneous things:

  • Right now, the cable from CM board ->MC board is a BNC. There appeared to be a differential 2-pin lemo hanging around for this purpose, but it didn't seem to be transmitting the signal. However, we will want something better than a BNC to keep this signal clean. 
  • I took SR785 TFs of the CM board from IN to the slow and fast outs. They looked reasonable, and will be posted in time. 
  • We enabled the 79:1.6k filter in the CM screen (though it is unclear if these are the actual values...), and put in its inverse in the digital path. I.e. we only want this shape in the AO path, to give it 1/f shape in the vicinity of the crossover. This is only necessary in the uncoupled cavity case. 
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