Generating a Linear Modulated Frequency Chirp for NI PXI 565x (5652)

[itoma054]

I am trying to produce a linear modulated frequency (or FM Chirp) with my NI PXI-5652 RF Signal Generator. My current strategy is to define the chirp pattern using the  "1020-bit, user defined bit stream" described in the user manual. I am having an issue, however, finding where in LabVIEW to define my bit stream and then to broadcast the chirp.

-How do I input my 1020-bit user defined bit stream? and/or

-Is there a better way to ramp the frequency to produce the chirp?

Thanks

[Bumblebee_Tuna]

Hello,

The PXI-5652 is not capable of outputting a continuous, linear modulated FM chirp/frequency sweep. With the PXI-5652 you are limited to 2-FSK, meaning a 0 would correspond to a frequency f1 and a 1 would correspond to a frequency of f2 in the modulated signal. You will need a vector signal generator to perform an FM chirp. 

-J

[itoma054]

Thank you Bumblebee_Tuna,

I also have an NI PXIe-5644R that I can use to produce the chirp signal. I have succesfully produced a chirp signal using the example program "RFSG Write Waveform From Binary File.vi" and the provided binary file "ChirpWaveform.bin". I have been trying to write a program in LabVIEW that produces an identical binary file as the "ChirpWaveform.bin", so that once I can succesfully duplicate the "ChirpWaveform.bin" then I can adjust the paramaters of my program to produce a chirp according to my own specifications.

I have been using the "Chirp Pattern.vi" to try to produce the same waveform, but I haven't had success yet.

Any hints?

Thanks

[Bumblebee_Tuna]

Here's another forum post detailing the creation of a .bin files for IQ data. This should help you get on the right path. 

http://forums.ni.com/t5/Signal-Generators/Create-bin-quot-Write-Waveform-from-File-vi-quot/m-p/40906...