Hi Jack,
The set/clear_command_time() functions have a parameter for the mboard that
defaults to 0 in gr-uhd. Try adding calls for the other mboard. Also, if
using frequencies between 500 MHz and 950 MHz on the UBX, you need to add
"dboard_clock_rate=20e6" to the device arguments.
Regards,
Michael
On Fri, Jun 16, 2017 at 10:06 AM, Jack Yang via USRP-users <
usrp-us...@lists.ettus.com> wrote:
> I am trying to build a coherent phase array receiver. I am using two X310
> with four UBX-160 and a ocotoclock (10MHz and 1PPS) to have 4 Rx coherent
> receiver. However, every time when the machine is on, the phase offset
> between each receiver is aways random. I used the python to write my system
> and I have the following setups. Could anyone give some hint or suggestion
> how to make coherent phase arrayed receiver work without non-consistent
> phase offset every time?
>
>
> Many thanks for your time!
>
> All Best,
> Jack
>
> """
> self.uhd_usrp_source_0.set_clock_source('external', 0)
> self.uhd_usrp_source_0.set_time_source('external', 0)
> self.uhd_usrp_source_0.set_subdev_spec('A:0 B:0', 0)
> self.uhd_usrp_source_0.set_clock_source('external', 1)
> self.uhd_usrp_source_0.set_time_source('external', 1)
> self.uhd_usrp_source_0.set_subdev_spec('A:0 B:0', 1)
> self.uhd_usrp_source_0.set_samp_rate(samp_rate)
> self.uhd_usrp_source_0.set_time_unknown_pps(uhd.time_spec())
>
> cmd_time = uhd.time_spec_t(0.1)
> timenow = self.uhd_usrp_source_0.get_time_now()
> self.uhd_usrp_source_0.set_command_time(timenow + cmd_time)
> self.uhd_usrp_source_0.set_center_freq(freq, 0)
> self.uhd_usrp_source_0.set_gain(gain, 0)
> self.uhd_usrp_source_0.set_antenna('TX/RX', 0)
> self.uhd_usrp_source_0.set_center_freq(freq, 1)
> self.uhd_usrp_source_0.set_gain(gain, 1)
> self.uhd_usrp_source_0.set_antenna('TX/RX', 1)
> self.uhd_usrp_source_0.set_center_freq(freq, 2)
> self.uhd_usrp_source_0.set_gain(gain, 2)
> self.uhd_usrp_source_0.set_antenna('TX/RX', 2)
> self.uhd_usrp_source_0.set_center_freq(freq, 3)
> self.uhd_usrp_source_0.set_gain(gain, 3)
> self.uhd_usrp_source_0.set_antenna('TX/RX', 3)
> self.uhd_usrp_source_0.clear_command_time()
>
> """
>
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>
>
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