Re: [Discuss-gnuradio] Synchronize phases between two N200

[Josh Blum]

On 09/26/2012 08:41 PM, Shih Oliver wrote:
> 
> Hi, I'm trying to synchronize two N200s in phases with both of them
> having GPSDO inside. I followedthe instructions on ettus for
> synchronizing channel phase. However, I got error message as follows,
>  UHD source block got error code 0x2gr_block_executor: source
> <gr_block gr uhd usrp source (19)> produced no output.  We're marking
> it DONE.UHD source block got error code 0x2gr_block_executor: source
> <gr_block gr uhd usrp source (18)> produced no output.  We're marking
> it DONE. and here's part of my code:bool start(void){        #ifdef

Its this a multi-device source? This error basically happens when it
fails to find an aligned time, which can happen if something in the
synchronization fails.

If I can suggest, it would be good to test the individual units to check

1) Is there a PPS signal, the examples/test_pps_input would do this for you

2) Is the GPS locked? There is a gps_locked sensor you can check

3) Do the GPS times agree once locked? There is a gps_time sensor as well

Both of these sensors can be checked from c++ or python.

http://files.ettus.com/uhd_docs/manual/html/gpsdo.html#using-the-gpsdo-in-your-application

-josh


> GR_UHD_USE_STREAM_API        _rx_stream =
> _dev->get_rx_stream(_stream_args);        _samps_per_packet =
> _rx_stream->get_max_num_samps();        #endif        //setup a
> stream command that starts streaming slightly in the future
> static const double reasonable_delay = 0.5; //order of magnitude over
> RTT        uhd::stream_cmd_t
> stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
> stream_cmd.num_samps = 200000;        stream_cmd.stream_now = false;
> stream_cmd.time_spec = uhd::time_spec_t(reasonable_delay);
> _dev->issue_stream_cmd(stream_cmd);        _tag_now = true;
> return true;    } Thanks for any help in advance. Best regards, 
> Oliver
> 
> 
> 
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