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.
TF agreed well with 2-time feCoeff4x and CDS time delay was -123.5 usec.
- 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
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.