[Discuss-gnuradio] periodic errors in assigning frequency with 2 B210's

[Lundberg, Daniel]

Hi all,

I have a gnuradio program that is controlling 2 B210’s.  The basic structure is that the program sleeps for a period of time, then tells one of the two B210’s to create a top block, transmit and receive, perform some math on the received streams, and save the result (a single number) to a file with a time stamp.  It then has the other radio perform the same set of measurements and save off the result to a different time-stamped file (I am comparing the behavior of two pieces of intermediate hardware over time to see if they have drifts that are well-correlated).  The radio serial number and the file name the result is written to are passed in as options when the top block is created.  This process takes place inside a for loop so that it can perform the measurements over a period of hours. 

 

All of those basic parts are working correctly, but I am getting an error every ~100 times or so that the top block is created.  I am trying to have the program run for ~1000 iterations, so this is pretty disruptive.  I have paraphrased the error below:

 

In __init__channels=range(2)

In __init__py line XXX in constructor_interceptor

In make return _uhd_swig.usrp_source_make(*args)

RuntimeError:  AssertionError: std::abs(freq)<=tick_rate/2.0

Occurring during

In void get_freq_and_freq_word

Which is in

…uhd/host/lib/usrp/cores/dsp_core_utils.cpp

 

 

I am using uhd 3.14.  Given that it looks like this error occurs in the basic uhd library, can you think of anything I am doing that might be more susceptible to creating this error?  For example, is the basic code structure of creating the top block every time the loop iterates counter to the gnuradio / uhd philosophy, and should I structure it another way that would be more stable?

 

Thank you,

Dan