So instead either leave UHD to do automatic master_clock_rate selection or set it to 20e6.
Regards, Derek On Tue, Apr 24, 2018 at 3:48 PM, Marcus D. Leech via USRP-users < [email protected]> wrote: > On 04/24/2018 10:37 AM, shachar J. brown via USRP-users wrote: > > Hi All, > > As I understand it, the B210 has maximum master clock rate of 61.44[MHz] > for one channel, and 30.72 [MHz] per-channel while using two channels. > > I am receiving through two channels, and would like to use a sample rate > of 20[MHz] with central freq. of 98 [MHz]. I set the master frequency to > max by editing the following line in the python file: > > * self.uhd_usrp_source_0.set_clock_rate(30.72e6, uhd.ALL_MBOARDS)* > > (Which is equivalent to writing "30.72e6" under "clock rate" in the > USRP-SOURCE block in the grc). > > To my utmost disappointment, I receive the following error: > > *[WARNING] [MULTI_USRP] The hardware does not support the requested RX > sample rate:* > *Target sample rate: 20.000000 MSps* > *Actual sample rate: 15.360000 MSps* > > Why is the master clock rate only half of what I assigned it? > (I did try to insert anything above 30.72e6 and received an error that it > exceeds the limit) > > Thanks for your time, > Steve. > > > Because your delivered-to-host sample rate has to be an integer fraction > of the master clock rate. Since you've "locked" the hardware at a master > clock rate of 30.72e6, the sample-rate-adjuster has no choice but to > clip your sample rate to one that can actually be supported by the > hardware configuration. > > > > _______________________________________________ > USRP-users mailing list > [email protected] > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > >
_______________________________________________ USRP-users mailing list [email protected] http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
