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    <div class="moz-cite-prefix">On 09/29/2014 04:04 PM, Chris Evans via
      USRP-users wrote:<br>
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              <div>All,<br>
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              I believe I might be running into the same issue that
              Stefan Ereth wrote about on 05/02/14 and maybe also what
              Robert Kossler wrote about on 05/23/14 regarding phase
              alignment of USRP B210 RX channels. I have a 2:1 splitter
              feeding both RX ports on the B210 and I'm using code
              similar to examples/rx_multi_samples.cpp. When I receive
              data from both channels, there is a seemingly random phase
              offset between the two sinusoids each time I run the
              program. However, if I issue_stream_cmd() multiple times
              in one program, the relative phase between the two
              received sine waves is the same.<br>
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            If I use GNURadio to receive on two channels, I consistently
            get the same relative phase offset. The relative phase
            offset seen in a GNURadio scope is the same as what I see
            when chipscoping the outputs of both DDCs.<br>
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          Using chipscope, I see that with GNURadio, radio_0/run_rx and
          radio_0/strobe_rx go high at the same time that radio_1/run_rx
          and radio_1/strobe_rx go high. With my UHD program, one
          channel starts receiving before the other (and I assume the
          other one starts streaming at some later time determined by
          software). <br>
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        How can I force both channels to receive synchronously?<br
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                        -- <br>
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                            <div>Chris Evans<br>
                              Systems Engineer<br>
                              Azure Summit Technology, Inc.<br>
                              3050 Chain Bridge Road, Suite 600<br>
                              Fairfax, VA 22030<br>
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                          919-428-6243 (cell)<br>
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      <pre wrap="">_______________________________________________
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    I would recommend you look at the way gr-uhd commences streaming on
    a multi_usrp object--it does some timed streaming, which will likely
    arrange for things to start at more-or-less the same time.<br>
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