Hello Martin, Thanks for the response.
I should have mentioned that the subdev spec was set to A:A B:A because I am using the basic RX boards. Trying "0:A 0:B" instead gives the following error: "0:A is not a valid rx subdevice specification on mboard 0. possible values are: [A:AB, A:BA, A:A, A:B, B:AB, B:BA, B:A, B:B]." Your suggestion to set the channel as 0,1,2,3 seemed to work perfectly (not sure how I missed that) as now I am getting four complex shorts out of my setup (an example of what is now in the buffer is shown below): (-3,-2)(3,0)(-1,0)(1,0) (2,-1)(0,0)(-3,0)(-2,0) (3,5)(1,0)(-1,0)(-1,0) (4,-2)(-4,0)(-1,0)(2,0) In getting the channels to stream however, I ran across another strange occurrence. After looking at the FFT data it appears as though the following commands only set the frequency of the first channel: uhd::tune_request_t tune_request(freq); usrp->set_rx_freq(tune_request); Channels 1,2, and 3 all show single peaks centered at 0 Hz in the FFT window. I was able to correct this by directly setting the frequency of each channel independently (as shown below) , but I was under the impression that when you create the usrp devices to begin with it should apply commands across all channels? uhd::tune_request_t tune_request(freq); usrp->set_rx_freq(tune_request, 0); usrp->set_rx_freq(tune_request, 1); usrp->set_rx_freq(tune_request, 2); usrp->set_rx_freq(tune_request, 3); Thanks again! This is really a great product and I look forward to getting more acquainted with what it can do. -Andrew ________________________________________ From: discuss-gnuradio-bounces+andrew.daigle=ll.mit....@gnu.org [discuss-gnuradio-bounces+andrew.daigle=ll.mit....@gnu.org] on behalf of Martin Braun [martin.br...@ettus.com] Sent: Tuesday, September 30, 2014 5:04 PM To: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Mulitple USRP Stream Confusion Hey Andrew, First, that subdev seems off -- I'd assume it's something like "A:0 B:0"? Next, I'm not even sure what you mean you set the channels to "0,1" on both devices. You should have 1 streamer, with a channel setting of "0,1,2,3". The 'args' string seems correct. Does this help? M On 30.09.2014 13:01, Daigle, Andrew - 1008 - MITLL wrote: > Hello! > > I am having trouble trying to create a continuous stream of complex > shorts from multiple (2) X310 USRPs (each running 2 channels) over a > single 1gigE switch (at a very low sampling rate); currently it appears > as though I can only stream from one USRP at a time and I can't seem to > figure out why. I should note I don't have this problem running each > USRP on its own dedicated network (but unfortunately that won't be > possible moving forward). > > To date, I have been using the rx_multi_samples example provided with > UHD (source 003.007.002). I don’t seem to have any issue connecting to > both USRPs and setting the parameters via the args=”addr0=192.168.10.2, > addr1=192.168.10.3” command. It is just that when I call rx_stream->recv > only the lights on the USRP which was listed first in args turn on. The > subdev spec and channel selection for each USRP is set to "A:A B:A" and > "0,1" and the incoming data from rx_stream is two channels of complex > shorts (not 4 like I would expect from 2 USRPs). > > Do I have to initiate the streams differently or am I missing something? > > Thanks! > > -Andrew > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
