Re: [Discuss-gnuradio] [USRP-users] Gnu Radio apps freezes (locks up)

[Josh Blum]

> Even if I just run an example with UHD-->Null sink (that is without any 
> rendering GUI) I get the exact same problem that samples stop coming after a 
> short period of time. 
> Or if I just try to save the samples to a file it stalls/stops and I can only 
> save relative few samples.
> 
> I think what Patrik describes in his responses is probably a different issue 
> which I sometimes also have experienced, but relates to the GUI, not 
> necessarily the UHD communication.
> In my case, the samples just stops coming from the device so I believe its 
> UHD related. 
> 
> IMPORTANT NOTE: The green LED labeled C on the N210 goes from a steady ON 
> (when samples are delivered) to suddenly OFF at the instant when samples stop 
> coming to the host computer.
> Also, the large orange LED goes from a steady ON when samples are streamed to 
> very rapidly blinking at the instant when samples stop coming.
> Finally, not until I abort the stalled application the fast blinking orange 
> LED turns off completely again. 
> 


LED C means the DSP is in RX mode. If continuous streaming is on, 3
things can cause this light to shutoff:

1) a stop streaming command packet (from issue stream command)
2) overflow in the device. This never happens on the network devices
unless the sample rate is > 25e6 and the wire format is still sc16
3) ICMP destination unreachable packet. This usually comes when the
kernel sees that a destination socket is not open.

I think you can eliminate 1 and 2. Can you confirm 3 with a wireshark run?

-josh