USRP underflow issue

GNU Radio
1

Hi everyone,

I’m new to Gnuradio and I have some problems with USRP N210 with WBX
daughterboards. I send data coming from udp socket to USRP and I am
encountering underflow issue.

I think that problem is due to the rate of the data transmitted to USRP.
I
have tried to set the sample rate in the USRP using different values.
Only
with the lowest value, 200 ksps, it seems to work (no underflow) but
increasing the sample rate underflow appears.

Moreover, I have repeated the test with 200 ksps more than once with the
same configuration and in some cases underflow appears.

Could you please help me?

Thanks

Irene

2

Hi Irene,

"U"nderflows occur when your application doesn’t supply samples fast
enough to the USRP. This is well-reflected by the fact that with the
lowest sampling rate things work.

Now, there might be different reasons, and the most prominent one is
that your data source ultimately doesn’t provide any faster. Also, if
your processing is very complex, your computer might become a
bottleneck.
Often, people get confused and use the “throttle” block in a flow graph
that actually contains hardware. Never ever do that!

Best regards,
Marcus