How to control Phase Noise Utility from GPIB?

[swchang]

Hi FG,

I cannot attend to www.labtab.com/ni_gpib0......   could you check it again?

I still not very understand about your way to solve this problem...

Anyone can explain more?? Thanks

sw

[Dennis_Knutson]

That web site only provided another interactive GPIB program. It wasn't anything that you don't already have with the tools in MAX. You can use the pdf file to give you some direction or make a request of ditto to publish his code. He twice claimed that he had something working but never post any VIs.

[tbd]

Hi sw,
      Just an FYI - if you're doing something like calculating integrated-phase-noise from 10Hz to 1MHz from a CW, there's a way to obtain a good approximation - and it executes %50 faster than the Phase-noise utility on the mass-memory module.  We make 6 spot-frequency measurements at, say, 10Hz, 100Hz, 1KHz, 10KHz, 100KHz, and 1MHz (from CW) then calculate/sum the phase-noise for each interval.  An accurate approximation may be possible by starting with the assumption that dBc vs log(F) is linear over each interval.  The straight-line approximation (dB/log(F)) is common-knowledge if you search this subject - but I couldn't find the integral calculation in the public domain.  If you're a math-wiz (or know one) start with:
m = (dBF1 - dBF2)/(F1dB-F2dB) => dBc as a function of F, or: dBc = dBF1 - mF1dB + mFdB.  This eventually leads to:
double-sideband [integrated] Phase-Noise = 2*K/(m+1)[F2^(m+1) - F1^(m+1)] <rad^2>

The integral equation was derived/supplied by an EE where I work, and simply handing-it-out seems wrong... but it (and K) can be derived from what's here.

then again...

Before giving-up on automating the phase-noise Utility, I concluded it was probably possible to write/edit functions stored on the mass-memory module - if so, then you have power over the Phase-noise Utility!

Luck/Cheers.  tbd (formerly Dynamik)

Message Edited by tbd on 12-13-2006 03:17 AM

[tin_win]

Hi demo,

            I also doing the Phase Noise Measurement using 85620a Mass Memory Module. But I could not figure out to control soft key like

Module --> User Keys--> Ph-Noise settings.

If you have done before, please help me how to control with LabVIEW.

Thanks,

tin win