"Failed to set frequency to ..." message in Spectrum scan

hello everyone,

I 'm trying to collect some samples from my spectrum sensing code
running on
USRP2, which is a slightly revised version of ‘usrp_spectrum_sense.py’.
My
problem is that after some time during the scan of some band, this
message
appears: “Failed to set frequency to …”. For instance I let the board
to
sweep my band 1000 times but after 100 or more scans (it’s really
variable)
it stops its normal operation and can’t lock on a frequency anymore.
I tested this with both WBX and XCVR front-ends in 400M and 2.4G. But
the
problem persists. Since I need to let the USRP2 work and collect samples
for
quite a long period, I really need to come up with a solution. I was
wondering if someone has already encountered this problem and has solved
it.

Rahman

On 04/30/2010 08:02 PM, Rahman Doost wrote:

the problem persists. Since I need to let the USRP2 work and collect
Discuss-gnuradio Info Page

Does the non-slightly-revised version do the same thing?

Well, the modification is for changing the code in such a way that it
works
on USRP2 since the original version is written for USRP. The rest is the
same. Also it does’t seem this is a programming bug since, it works for
some
time and then it crashes.

Rahman

On 04/30/2010 08:17 PM, Rahman Doost wrote:

Well, the modification is for changing the code in such a way that it
works on USRP2 since the original version is written for USRP. The
rest is the same. Also it does’t seem this is a programming bug since,
it works for some time and then it crashes.

Rahman

O
What happens when you exit the program, and then go back in, does it
recover?


Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium

Again the same, works for some time, then crashes!

On 04/30/2010 09:59 PM, Rahman Doost wrote:

since,
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org

I suspect that some resource, perhaps file descriptors, are “leaking” on
each iteration of the
scan. Possibly because the device is being re-instantiated on every
iteration?

On 05/01/2010 04:40 PM, Rahman Doost wrote:

I checked and they’re not hundreds. In fact there does not seem to be
anything unusual about that.
Plus I see some ‘S’ sequences every 3 or 4 failed scans too. In USRP2
usage FAQ, it says this happens when packets are dropped. But I don’t
know which one causes the other one.

Rahman

The next thing to check for is a gross memory leak. There is clearly
some resource that is leaking,
probably on the host side. Because when you re-start the application,
everything is just fine for a while
after that, correct?


Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium

Yes that’s correct. It always works fine at the start.