Dear Derek, thanks! Last question, are there any commands in the C API that do the same as the following ones?
//we will tune the frontends in 100ms from now uhd::time_spec_t cmd_time = usrp->get_time_now() + uhd::time_spec_t(0.1); //sets command time on all devices //the next commands are all timed usrp->set_command_time(cmd_time); //tune channel 0 and channel 1 usrp->set_rx_freq(1.03e9, 0); // Channel 0 usrp->set_rx_freq(1.03e9, 1); // Channel 1 //end timed commands usrp->clear_command_time(); Kind Regards, Felipe On Tue, Jun 19, 2018 at 4:52 PM, Derek Kozel <derek.ko...@ettus.com> wrote: > Hello Felipe, > > The oscillator will *start* tuning at the time stamp you specify. You will > have to characterize the settling time for your frequency hops and schedule > the tunes in advance of when you need to be at the new frequency. Depending > on what frequencies you are moving between and which daughterboard you are > using the settling time changes. It is important to note that timed commands > are executed in the order the are issued, not in chronological order, so you > must issue them in chronological order for to get the expected behavior. > > Regards, > Derek > > On Tue, Jun 19, 2018 at 3:45 PM, Felipe Augusto Pereira de Figueiredo > <zz4...@gmail.com> wrote: >> >> Dear Derek, thanks for your prompt reply! >> >> I'm using an x310. >> >> Just to clarify, I want to make sure that the frequency I'm setting is >> only valid and guaranteed for that specific starting point (the >> timestamp into the future). Right now, when I send just the time >> command and change the frequency for the next packet I see with the >> spectrum analyser that the packets do not have the right frequency, >> instead, they are spread over the spectrum as the oscillator might be >> still under configuration, calibration, etc. >> >> Therefore, I hope that with the timed commands I will be able to have >> a better control over freq/time resources. >> >> Thanks and Kind Regards, >> >> Felipe >> >> On Tue, Jun 19, 2018 at 4:37 PM, Derek Kozel <derek.ko...@ettus.com> >> wrote: >> > Hello Felipe, >> > >> > Yes it is possible. What USRP are you using? Some, such as the B200 and >> > E310 >> > cannot set the frequency using timed commands as the tuning is done by >> > the >> > RFIC rather than the FPGA. There is a small example of tuning in the >> > manual. >> > http://files.ettus.com/manual/page_sync.html#sync_phase_lo >> > >> > And a longer program using timed commands in the examples. >> > >> > https://github.com/EttusResearch/uhd/blob/maint/host/examples/test_timed_commands.cpp#L74 >> > >> > The TwinRX fast frequency hopping example does not show the use of timed >> > commands for changing the local oscillator frequency, but does show very >> > efficient burst reception. >> > >> > https://github.com/EttusResearch/uhd/blob/maint/host/examples/twinrx_freq_hopping.cpp >> > >> > Regards, >> > Derek >> > >> > >> > On Tue, Jun 19, 2018 at 3:15 PM, Felipe Augusto Pereira de Figueiredo >> > via >> > USRP-users <usrp-users@lists.ettus.com> wrote: >> >> >> >> Dear All, >> >> >> >> I've seen that with the gnuradio API it is possible to set a frequency >> >> and time in the future for a bursty transmission. With that feature it >> >> is possible to implement frequency hopping without any big trouble. >> >> >> >> I'd like to know if the same is possible with the UHD API, and if so, >> >> how can I do that? One example would be great. >> >> >> >> Thanks and Kind Regards, >> >> >> >> Felipe Augusto >> >> >> >> _______________________________________________ >> >> 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
