For what it's worth, I was able to reproduce the behavior described here, but didn't get to dig into it much. My leading suspicion would be what Rob mentioned about timestamping. Lukas' code sets a command time, but I'm not clear on how timestamp metadata for packets being sent to the radio are handled. Might be a good question to loop the discuss-gnuradio mailing list in on?
Sam Reiter On Tue, Mar 3, 2020 at 10:59 AM Rob Kossler via USRP-users < usrp-users@lists.ettus.com> wrote: > I wonder if the issue is related to a missing time stamp on the baseband > samples going from GR to UHD. If the stream does not have a time stamp, > the DUC is unable to apply the timed command because the DUC does not > really know the time - it must pull the time from the streaming samples. > This is in contrast to the radio block which does have access to time and > can apply timed commands by referring to the motherboard clock. > > I am not too familiar with GR so I'm not sure how to know if GR is putting > a time stamp on the streaming samples. > Rob > > On Mon, Mar 2, 2020 at 10:04 AM Lukas Haase via USRP-users < > usrp-users@lists.ettus.com> wrote: > >> Hi Marcus, >> >> Thank you that would be amazing! >> >> I followed the tutorial and built everything from source: >> >> $ lsb_release -a >> No LSB modules are available. >> Distributor ID: Ubuntu >> Description: Ubuntu 18.04.4 LTS >> Release: 18.04 >> Codename: bionic >> $ uname -a >> Linux sdr 5.3.0-40-generic #32~18.04.1-Ubuntu SMP Mon Feb 3 14:05:59 UTC >> 2020 x86_64 x86_64 x86_64 GNU/Linux >> $ cd uhd >> $ git status >> HEAD detached at v3.15.0.0 >> $ cd ../gnuradio >> $ git status >> HEAD detached at v3.7.14.0 >> >> >> Thank you! >> >> Lukas >> >> >> >> PS: For some reason I sometimes do not get responses from this list. I >> just saw it looking at the mailman archives. Hence I cannot respond (to >> keep headers intact) but need to create a new message and manually "quote". >> I hope that still preserves the context somehow. >> >> >> >> Marcus Leech wrote: >> > On 02/28/2020 01:01 PM, Lukas Haase via USRP-users wrote: >> >> Hi again, >> >> >> >> I created a minimum example (gnuradio) that shows the issue described >> below. >> >> To summarize: Retuning to a different dsp frequency on an USRP X310 >> (+UBX160) does not work (command ignored) ONLY if a timed command (in >> future is used). >> >> The code shows it in a simple manner. Commenting out the single line >> with set_command_time makes the example work. >> >> >> >> I am absolutely out of ideas and would appreciate any input! >> >> >> >> Best, >> >> Lukas >> > Lukas. >> > >> > Thanks for sticking with this. I'll have a discussion with Ettus R&D to >> > see if this is a known issue and/or if there's a workaround. >> > >> > Remind me which version of UHD you're using? >> >> >> >> _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >
_______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
