[Discuss-gnuradio] Understanding USRP2 flow control

[OE1RSA]

Dear All!

I am starting to learn my new USRP2 device.
I bought a reasonable fast quad core PC and
a recommended ethernet board.

I wanted to find out if I can get the interpolation 4
working in my environment. I just connect a sine
oszillator to the usrp2 sink.

I am observing the signal on a connected scope.

Everything works fine for a while, but then suddenly
the output becomes heavily distorted.

I can see from the resource watch of the system
monitor that my PC putting out data at a sustained
rate of more than 800 Mbits/sec.

I started to try to understand the code in
gnuradio/usrp2/host/lib and expected some flow control
when the usrp2 input buffers are nearly full .
Unfortunately I was not able to understand how this
is implemented.

Is there any flow control at all?
If not, what is supposed to happen, if the PC is
sending (slightly) too fast?

Appreciating any information on this subject,
Roland

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  _  _  | Roland Schwarz OE1RSA
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