[Discuss-gnuradio] to control CORDIC module to synchronize in USRP through GNU Radio

[Simona Sibio]

Hi all, 

I am working with GNU Radio 3.7.13.4, two N200 USRPs and a X310. 

I would like to control the CORDIC module because I wuold like to synchronize the phase in USRPs.

I found the following commands for UHD for receiver and for transmitter:

uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);

stream_cmd.num_samps = samps_to_recv;

stream_cmd.stream_now = false;

stream_cmd.time_spec = time_to_recv;

usrp->issue_stream_cmd(stream_cmd);

uhd::tx_metadata_t md;

md.start_of_burst = true;

md.end_of_burst = false;

md.has_time_spec = true;

md.time_spec = time_to_send;

//send a single packet

size_t num_tx_samps = tx_streamer->send(buffs, samps_to_send, md);

But I have two problems:

1) I don't know how I can use this commands. Can I send this commands directly in the terminal or can I use some setting in UHD:USRP Source and UHD:USRP Sink?

2) I read that I can do the synchronization only with X-series, I cannot do the synchronization in phase with the N-series because there is the FPGA Spartan 6, doesn't it? Or is there some other problem?

Thank you for every help.

Best Regards,

Simona