Thanks a lot once again Marcus. I'm so grateful for a level oh help I get on this forum.
On Sat, Mar 10, 2018 at 7:11 PM, Marcus D. Leech <[email protected]> wrote: > On 03/10/2018 09:26 PM, Sailor Jerry wrote: > > Thanks a lot Marcus, > > Let me restate my question in terms of the rx_samples_to_file.cpp code. > What line of code does turn the RX logic on? > > I thought that once I'm passed check_locked_sensor() everything is > initialized. I guess the right answer is that the actual initialization > starts somewhere after rx_streamer::issue_stream_cmd() is called, > correct? Then I should discard few milliseconds worth of data that came > form rx_streamer::recv() > > Yes, start-of-streaming generally does the last stage of turning the > receiver chain on. For example, it cannot really do DC-offset correct on a > data stream > that hasn't started yet.... > > > > > > On Sat, Mar 10, 2018 at 5:53 PM, Marcus D. Leech via USRP-users < > [email protected]> wrote: > >> On 03/10/2018 08:41 PM, Sailor Jerry via USRP-users wrote: >> >>> I'm using the rx_samples_to_file to capture the data. >>> >>> I have pure noise connected to input. If I plot first few milliseconds >>> of IQ data I see some pull-in process. Interestingly enough this pull-in >>> time doesn't depend on parameter "--setup". >>> >>> Is it some fancy IQ calibration? >>> When does the samples capture start? >>> Should I ignore first samples? >>> >>> Thanks a lot. >>> >>> You're capturing an analog process, so there's no way to definitively >> say sample <X> is your first valid sample. >> >> It takes a few msec for the DC-offset and I/Q compensator on the AD9361 >> to reach some kind of equillibrium when the RX logic is turned on. It takes >> a while for analog filters and other analog "bits and pieces" to reach >> steady-state operations. >> >> It takes a while for whatever DDC filters are in play to reach >> steady-state operations. So, a few milliseconds on RX startup is actually >> pretty good in >> my book... >> >> >> >> >> _______________________________________________ >> USRP-users mailing list >> [email protected] >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> > > >
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