I am using a master clock rate of 48 MHz and a sample rate of 8 MHz.
On Mon, Jun 15, 2020, 4:41 PM Marcus D. Leech <patchvonbr...@gmail.com>
wrote:
> On 06/15/2020 03:42 PM, Aaron Smith wrote:
> > I am using the python api.
> >
> > usrp = uhd.usrp.MultiUSRP()
> >
> > # Set gain, clock rate, sample rate etc...
> >
> > usrp.set_clock_source('external')
> > usrp.set_time_source('external')
> >
> > ts_reset = uhd.types.TimeSpec(0.0)
> > usrp.set_time_next_pps(ts_reset)
> > time.sleep(1.0)
> > last_pps = usrp.get_time_last_pps().to_ticks(1e9)
> > if last_pps % int(1e9) != 0:
> > print("Error failed to align clock")
> >
> > # The signal is complex float data, scaled to a max amplitude of 0.9
> > approx 0.1 secs in duration
> > signal_data = numpy.fromfile('signal.dat',dtype=numpy.complex64)
> >
> > wirefmt = 'sc16'
> >
> > sa = uhd.usrp.StramArgs('fc32',wirefmt)
> > sa.channels = [0]
> > stream = usrp.get_tx_stream(sa)
> >
> > # Send 3 seconds in future
> > send_time = usrp.get_time_last_pps().get_real_secs() + 3.0
> > metadata = uhd.type.TXMetadata()
> > metadata.has_time_spec = True
> > metadata.time_spec = uhd.types.TimeSpec(send_time)
> >
> > stream.send(signal_data, metadata)
> >
> > # Ensure the transmission is complete before returning
> > time.sleep(4.0)
> >
> > sys.exit(0)
> >
> >
> This probably has to do with uncertainty in the way the 1PPS signal is
> flopped into the device. What sample rate are you using, and what
> master clock rate?
>
>
>
_______________________________________________
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
