Yes, the example was for illustration only. You can throw a couple of DDCs in between the radio and add/sub block to slow the rate down. But, the questions are still the same.
On Wed, Mar 20, 2019 at 7:49 PM Nick Foster <bistrom...@gmail.com> wrote: > First things first. The flow graph you're describing don't work because > the two radio blocks will saturate the bus going into the addsub block. You > will need to decimate the streams going into the addsub block. > > I don't have a ready answer to your question about the streamers, but I'd > suggest using timed commands to align the two radio streams, if UHD isn't > smart enough to recognize the two radios and propagate the stream command > accordingly. > > Nick > > On Thu, Mar 21, 2019, 6:46 AM Rob Kossler via USRP-users < > usrp-users@lists.ettus.com> wrote: > >> Hi, >> I am starting to develop more complicated RFNoC graphs and several >> questions occurred to me. I am using my own C++ application with the UHD >> RFNoC-enabled library. >> >> Consider a receive-only RFNoC graph with 2 radio blocks feeding a >> 2-input, 2-output Add/Sub block. Also, assume there are two rx_streamers >> connected to the 2 output ports of the Add/Sub block. Note that these >> streams are no longer independent or one-to-one matched with the radio >> channels. >> >> 1) How does an "issue_stream_cmd()" to one of the Add/Sub block ports >> propagate back to the radio block? Actually, it would need to propagate >> back to both Radio blocks no matter which rx_streamer I used since they are >> no longer independent streams. Does this make sense? >> 2) What happens if I only call "issue_stream_cmd()" for one of the >> rx_streamers instead of both? Perhaps since the other streamer isn't >> running, it backpressures the streaming such that it eventually quits and >> thus quits for the other port as well? >> 3) Do I have to do anything in the Add/Sub block to sync up the streams >> or can I rely on the first sample from Radio 0 being time-aligned with the >> first sample from Radio 1 (assuming I issued timed start commands)? >> >> Rob >> _______________________________________________ >> 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
