On Tue, 06 Nov 2018 15:42:10 -0500 "Marcus D. Leech" <patchvonbr...@gmail.com> wrote:
> On 11/06/2018 12:23 PM, Gwenhael Goavec-Merou wrote: > > On Tue, 06 Nov 2018 12:09:02 -0500 > > "Marcus D. Leech" <patchvonbr...@gmail.com> wrote: > > > >> On 11/06/2018 10:24 AM, Gwenhael Goavec-Merou wrote: > >>> On Tue, 06 Nov 2018 09:40:09 -0500 > >>> "Marcus D. Leech via USRP-users" <usrp-users@lists.ettus.com> wrote: > >>> > >>>> On 11/06/2018 04:12 AM, Gwenhael Goavec-Merou via USRP-users wrote: > >>>>> Hi, > >>>>> > >>>>> My environment is: > >>>>> USRP: X310 with basicRX (currently one but 6 in a near future) > >>>>> UHD: 3.13.1.0-rc1 > >>>>> GNURadio: 3.7.13.4-r2 > >>>>> gr-ettus: master branch, up to date > >>>>> > >>>>> I need to sample 4 real signal / USRP and to demodulate / decimate > >>>>> before transfer to the PC. > >>>>> > >>>>> I have created a GNURadio flow with: > >>>>> - 2 Radio (id 0 and 1), configured with 2 channels > >>>>> - 2 DDC (id 0 and 1), with 2 channels, with a center frequency fixed to > >>>>> XX MHz > >>>>> - 4 complex To Real; > >>>>> - 1 QT Gui with 4 inputs. > >>>>> > >>>>> Each channel of each radio is connected to an DDC input (radio0 channel > >>>>> 0 to DDC0 input 0, radio0 channel 1 to DDC0 input 1, etc.) > >>>>> > >>>>> With this setup and with an input configured as XX + YY MHz (to have a > >>>>> beatnote) I'm able to see a sinusoid on the qt for all channels (if I > >>>>> plug / unplug an input signal the corresponding plot is equal to 0 or > >>>>> displays the signal). > >>>>> But: > >>>>> 1/ the console panel display continuouly messages about channels overrun > >>>>> 2/ the data flow is not continuous (visible in qt plot) (I suppose is > >>>>> due to 1/ ) > >>>>> 3/ channels are not aligned (I suppose is due to 1/ and/or 2/ > >>>>> > >>>>> Theorically, by reading HDL files for the X310 firmware it's seems > >>>>> possible to use this configuration. > >>>>> > >>>>> Then, how to fix my issue? > >>>>> - Is it a USRP/UHD limitation? > >>>>> - gr-ettus seems not heavily upgraded, is something must be modified in > >>>>> this repository? > >>>>> - I am just wrong somewhere on my design? > >>>>> > >>>>> Thank you very much > >>>>> > >>>>> Gwen > >>>>> > >>>> What is the sample rate as delivered to the PC? What kind of PC? > >>> The sample rate is 3MS/s for each channels after DDC (200MS/s before due > >>> to the ADC). > >>> My PC is a Lenovo thinkpad x230 with a 1Gb ethernet card. > >>>> Overrun means that your PC isn't keeping up with the sample flow. > >>>> > >>> I've just done several test with only 2 channels : > >>> - 2 radio, 1 channel/radio and 2 DDC with 1 input (first on radio0, a > >>> second radio1) : > >>> - data continuous (but not synchronized) > >>> - no message on display panel > >>> - 2 radio, 1 channel/radio and 1 DDC with 2 input : > >>> - console panel displays continuouly "Ooverrun on chan 0" > >>> - data not continuous > >>> - after a short time : freeze > >>> - 1 radio with 2 channels and 1 DDC with 2 input : > >>> - console panel displays continuouly "Ooverrun on chan 0" and > >>> "Ooverrun on chan 1" > >>> - data not continuous. > >>> - 1 radio with 2 channels and 2 DDC with 1 input : > >>> - console panel displays continuouly "Ooverrun on chan 0" > >>> - data not continuous. > >>> > >>> So, the first test seems to show it's possible with my computer to > >>> receive 2 channel 3MS/s without overrun. Other tests seems to show a > >>> problem for radio and/or for DDC to send or receive the full speed ADC > >>> flow. > >>> > >>> Thank. > >>> > >>> Gwen > >> The only immediate comment I have is that 3Msps is not a valid rate for > >> the DDC with a 200Msps input--rates must be an integer fraction > >> of the input sample rate. > > Tested with 2Msps this the same result... > >> It would be helpful if you shared your flow-graph for the cases that > >> don't work. > > joined > > > > Gwen > Also, in your Radio BLock, you have "E310: 2 channels" selected, which > very likely doesn't work with X310. > I've checked multiple time the flow-graph, top_block.py, do grep in gr-ettus, uhd, gnuradio sources and I'm unable to find this option... Maybe we have different version of one piece of code... I've forget to specify : to be able to select antennas according to basicRX requierement (A or B) I've modified uhd_rfnoc_radio.xml to add this entry (I must to sent a patch to fix this). Gwen _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
