RFSG example - write waveform from file

[FW00]

In this NI-RFSG version 1.2 there is a new vi called "Write Waveform from File.vi".

It load the file "Chirp.bin" into on board memory and up-converter to  user expect frequency and power.

I have several question on using this.

1. Is possible to use RFSA to capture waveform and storage into this format "xxx.bin" for this RFSG example? Is there any Vi or VC++ able to do it? Or..

2.Is there any file size limitation of "xxx.bin"? Since we are using the on board memory of PXI-5441(32MB) so we would like to know the limitation.

I also found a examples called "ni5660_Fetch_and_Write_IQ_Data_in_Chunks.vi". But it storaged into I.bin and Q.bin. These 2 files looks not so suitable for "Write Waveform from File.vi". Or maybe my setting isn't correct. Or maybe it should not be separate to I-Q.(use IF??)

I am trying to capture a 2.048MHz signal into  "xxx.bin" and use RFSG to re-generate it.

Is possible to guide me to do it? Thanks a lot.

I appreciated!

[kalyanramuv]

Hello,

Thank you for using National Instruments discussion forums. *.bin files stand for binary files. Yes, you can store your acquired data from NI-RFSA into the *.bin so that it can be read back for NI-RFSG. For binary files, the trick is knowing the format in which data is stored. For example, if the data is stored as array of complex numbers or array of integers etc.,

I searched for  the VI you referred in RFSG palette in LabVIEW, "Write Waveform from File.vi" and couldn't find it. Could you post the path of the VI you are referring to. That will let me help you better.

Thanks,

Kalyanramu Vemishetty

Applications Engineer

National Instruments

[FW00]

File: Write Waveform From File.vi

Path:

C:\Program Files\National Instruments\LabVIEW 8.0\examples\instr\niRFSG\niRFSGExamples.llb

File:   Chirp.bin

Path:

C:\Program Files\IVI\Drivers\niRFSG\Examples\Waveforms

The "Write Waveform from File.vi" is using "Chrip.bin". So I put these 2 files location for you.

[kalyanramuv]

Hi,

Thanks for the response with file path, it was helpful.

After looking at the code it became clear as what the data format inside the binary file was. The binary file stores data in I16 (signed 16-bit format). Each I and Q data point will scaled to the range of I16 and then stored in contiguous locations.

I am attaching an simple example for IQ Write and IQ Read to help you understand writing and reading IQ Data. In the attached zip file, IQ Write demonstrates how to write to a file and IQ Read demonstrates how to read form file.

Have a great day!

Thanks,

Kalyan