Re : How to synchronize sampling on PXIe-5162

[RobertSTR]

Hi, I need to characterize phase and amplitude imbalance of two quadrature signals from a 14bit TxDAC. I selected two 5162 modules to do the job. The signals can have a frequency of up to 1.2GHz..

Is PXIe-5162 capable of doing this job?

The plan was to record a long sample of the signals and then do the processing in ie. Matlab.

I am facing a few problems. Is it possible to synchronize sampling of all channels on one 5162 module, and how to synchronize sampling of 2 x 5162 modules with enough accuracy to have a phase resolution below 1deg?

Are there any examples of how to synchronize sampling of multiple channels/modules in LabView ?

Can the phase and amplitude measurement be done directly in LabView without involving Matlab?

[=Jean]

Hi Robert,

Did you already read some white paper and KB about synchronization using LabVIEW?

https://www.ni.com/en/support/documentation/supplemental/10/synchronization-explained.html

https://www.ni.com/en/support/documentation/supplemental/06/timing-and-synchronization-features-of-n...

You can find some other white papers on ni.com. I think this will be a good start before doing something else.

You also can search in the LabVIEW examples.

Here some information about the measurement of the phase and the amplitude:

https://www.ni.com/docs/en-US/bundle/labview-api-ref/page/vi-lib/analysis/0measdsp-llb/amplitude-and...

https://www.ni.com/en/support/documentation/supplemental/06/statistical-visualization-in-labview.htm...

Let me know if it is good 🙂

[RobertSTR]

Thanks for a reply.

I read a bit about the NI-TCLK synchronization. Does it apply to module-to-module sunchronization or is it used within one module too?

I found this page

Overcome the Challenges of Building High-Channel-Count, High Speed Measurement Systems

It says 30ps skew after manual calibration, which is not enough for my application.

I didn't find any information about the sampling skew for converters within one module.

I recall a number 12ps from some previous research but I cannot find it now. 12ps within one module is still too much.

[=Jean]

Hi Robert,

From the datasheet of the 5162 (https://www.ni.com/docs/en-US/bundle/pxie-5162-specs/page/specs.html) page 20, its says that using the manual calibration you can synchronize two identical 5162 with less than 5ps.

Here some other information:

https://www.ni.com/en/shop/pxi/national-instruments-ni-tclk-technology-for-timing-and-synchroni.html...                                                                          

Is that answering your questions?

Have a nice weekend.