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Entry  Sat Oct 30 05:27:53 2010, yuta, Summary, CDS, CDS time delay measurement delaysetup.pngCDSdelay.png
    Reply  Sat Oct 30 14:35:43 2010, Koji, Summary, CDS, CDS time delay measurement CDS_system_investigation_090323.pdf
       Reply  Mon Nov 1 15:47:15 2010, yuta, Summary, CDS, CDS time delay measurement downupsampling.pngCDSdelay2.png
          Reply  Mon Nov 1 16:43:24 2010, Koji, Summary, CDS, CDS time delay measurement 
             Reply  Sat Nov 20 03:37:11 2010, yuta, Summary, CDS, CDS time delay measurement - the ripple c1tst16Kdelay.png
Message ID: 3838     Entry time: Mon Nov 1 15:47:15 2010     In reply to: 3830     Reply to this: 3839
Author: yuta 
Type: Summary 
Category: CDS 
Subject: CDS time delay measurement 

Background:
  I measured CDS time delay last week, but because of my lack of understanding the system, it was incorrect.
  IOP has an anti-aliasing filter before downsampling from 64kHz(65536Hz) to 16kHz(16384Hz) and also has an anti-imaging filter before upsampling from 16kHz to 64kHz.
  So, I should have take feCoeff4x into account twice.
downupsampling.png

Result:
  TF agreed well with 2-time feCoeff4x and CDS time delay was -123.5 usec.
CDSdelay2.png


Plan:
 - make AWG(, diaggui TF measurement, tdssine) work
 - check input/output filter switching (using tdssine & tdsdmd)
 - measure openloop TF of MC suspension damping
 - divide it with my expectation and see if there are any filters I don't know

Quote:

Unsatisfactory.

Neglecting the digital anti-imaging filter makes the discrepancy. You must take into account your digital filter twice.

I attached the slides I made during my visit for March LVC '09. P.5 would be useful.

 

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