Pre-record a waveform in a USRP

[jlgomez1989]

Hi, I'm currently working with Labview 2017 and 2 USRP 2954R. I'm trying to build a wireless system that sends a signal from one USRP to the other one. The signal sent from Tx to Rx is the same for the entire transmission. So, I'm wondering if there is any way to record my signal into the USRP before the transmission starts because right now, my signal is sent from my computer to the USRP using the default buffers given by Labview (DMA FIFO).

I know that recording a signal into a USRP is possible (for Ettus E310) but I don't know if the 2954R has the same capability.

Thanks in advance for any help you can give me.

Regards

Jorge 

[DylanDylanDylan · Accepted solution]

You can take advantage of the FPGA to store data:

http://zone.ni.com/reference/en-XX/help/371599N-01/lvfpgaconcepts/fpga_storing_data/

[AgentAstronaut]

DylanDylanDylan's answer is correct if you are modifying the FPGA on your USRP. It looks like that is what you are doing, so his is probably a good solution.

For others coming to this thread.

I will note that if you are using the Host API you can take advantage of the strategy implemented in the niUSRP EX Tx Multiple Outputs (Single Device, Multi-Channel).vi, or niUSRP EX Tx Finite Sync.vi, to load samples onto the USRP before outputting the data.

These take advantage of the start trigger timer on the USRP.

Cheers,

Michael