Hi, looks like gnuradio is freezing due to the massive amount of underflows ocurring. First try replacing the constant source with two separate analog fast noise sources connected to the dma fifo - this might help if indeed the problem is that the PC is being too slow to generate samples. Secondly, revert the dma fifo depths to the default 32M and see if it has any effect but I suspect the first option should fix your issues. Also it's definitely helpful to test each single tx chain on its own to make sure it works as expected before trying both together!
Assuming you are using an x310, the sampling rate on the radio block should be set to 200 megasamples/per sec, similarly the DUC output rate should also be 200 megasamples/per sec. On the receive side, the radio block's sampling rate should again be set to 200megasamp/sec with the DDC input rate being set to the same as well. Also the analog bandwidth in the context of the tx side just adjusts some filters I believe - so I'd leave it at the default of 56Mhz. On the rx side I'd also leave it at the default of 56Mhz unless you have some interferer in that range that you'd want to avoid. On Sat, Nov 18, 2017 at 4:53 PM, Bakshi, Arjun < bakshi...@buckeyemail.osu.edu> wrote: > Hi, > > > I've installed the correct uhd/gnuradio/gr-ettus packages now, and > constructed the attached flow graph. However, the application hangs up > after a second or so. Underflow warnings also appear almost immediately > after the flow starts. > > > Image of flow graph and error attached. GRC file also attached. > > > An earlier email mentioned: > > ==== > > Also you may get underflows depending on your > sample rate, in my case these were solved by moving the bpsk transmit > chain to fabric (RFNoC) as the host was not fast enough to generate > samples otherwise. > > ==== > > > However my sampling rate is pretty low. 1Msps. With 2xN210 I can support > ~5Msps tx+rx on this PC. > > > Any ideas on whats going on, and how to fix it? > > > Also, what are DUC input/out rates? What should the "analog bandwidth" be > set to? Same as sampling rate or 0, or something else? > > Thank you, > > > AB > ------------------------------ > *From:* Bakshi, Arjun > *Sent:* Monday, November 6, 2017 2:01:16 PM > *To:* Michael Carosino > > *Cc:* discuss-gnuradio@gnu.org > *Subject:* Re: [Discuss-gnuradio] X310 with 2 WBX in full duplex > > > Thanks for the pointers. I'll look into them soon. I've temporarily moved > to another setup. Will report back when I come back the this one. > > > Thanks, > > > AB > ------------------------------ > *From:* Michael Carosino <m.caros...@gmail.com> > *Sent:* Friday, November 3, 2017 3:38:37 PM > *To:* Bakshi, Arjun > *Cc:* discuss-gnuradio@gnu.org > *Subject:* Re: [Discuss-gnuradio] X310 with 2 WBX in full duplex > > Hi, > > I don't believe you need to install Xilinx/vivado/etc - that's only needed > if you want to create your own rfnoc blocks (like I did for the > transmitter, but ideally you avoid this as its a lot of work!). > > You should simply need the UHD rfnoc_devel branch installed w/gnuradio and > use the image downloader to download the precompiled image for > usrp_x310_fpga_HG > and flash it to the x310. (usrp_x310_fpga_HG contains 2x DDC, 2x DUC, 2x > Radios, and 1x DMAFIFO which is all you should need per my previous > pictures). > > For instructions, see https://kb.ettus.com/Getting_Started_with_RFNoC_ > Development#Testing_the_default_FPGA_image_and_ > building_from_existing_blocks and also flashing instructions here > http://files.ettus.com/manual/page_usrp_x3x0.html#x3x0_load_fpga_imgs > > On Fri, Nov 3, 2017 at 8:42 AM, Bakshi, Arjun < > bakshi...@buckeyemail.osu.edu> wrote: > > Thanks for the quick reply, Michael. I looked into installing RFNoC and > thats going to need vivado/xilinx, and a bunch of other stuff. > > > Trouble is that I don't have +20GB to spare needed for its installation. > Is there any way around it? What are the bare minimum options required? I > tried installing the Vivado Lab Solutions instead, but I guess thats not > enough as I couldn't get ettus's fpga software to build after just that. > > > Install options image attached. > > > Thanks, > > > AB > ------------------------------ > *From:* Michael Carosino <m.caros...@gmail.com> > *Sent:* Thursday, November 2, 2017 10:21:52 PM > *To:* Bakshi, Arjun > *Cc:* discuss-gnuradio@gnu.org > *Subject:* Re: [Discuss-gnuradio] X310 with 2 WBX in full duplex > > Hi, > > I've successfully gotten the two tx-rx setup on an x310 you've > described but I did it somewhat differently. Instead of using the usrp > source/sink blocks I ended up using the RFNoC blocks - the main reason > for this is because a USRP Sink block is made up of the following > RFNoC blocks: RFNoC DMAFIFO -> RFNoC DUC -> RFNoC Radio. It turns out > that the DMAFIFO included by the USRP Sink block has a default depth > size of 32MB and this results in multiple seconds of delays for the > sample rates I was using (Ettus includes this fifo due to some flow > control latencies in their protocol that they use for transport > between the USRP and host over ethernet). > > Anyways, by manually creating the radio chain in RFNoC as described > above, you can adjust the default depth size of the DMAFIFO. By > playing around I found that a depth of 2^20 = 1.04MB worked well. It > is also of note that if you do this method you need four total radio > blocks - 2 for transmit and 2 for receive (for some reason the > multi-channel selection in the rfnoc radio block did not work, this > method does however). > > I would also run 'ethtool -G eth0 rx 4096' to ensure packets aren't > dropped in your NIC. Also you may get underflows depending on your > sample rate, in my case these were solved by moving the bpsk transmit > chain to fabric (RFNoC) as the host was not fast enough to generate > samples otherwise. > > Finally, you will probably experience occasional errors on flow graph > startup about synchronization errors (timeout waiting for PLL to lock, > backend sync failed, unexpected fifo depth), retrying to run the > flowgraph (sometimes it takes a few tries) will usually get it > running. I've spoken to Ettus about this and they are tracking this > issue so hopefully its solved soon. > > Attached a picture of transmit/receive configuration in RFNoC. > > regards, > Michael > > > > On Thu, Nov 2, 2017 at 7:12 PM, Bakshi, Arjun > <bakshi...@buckeyemail.osu.edu> wrote: > > Few mistakes I caught after sending it. Center frequencies I had chosen > were > > out of range for WBX. Fixed now. Also, image file now has proper > extension. > > > > > > Thank you, > > > > > > AB > > > > ________________________________ > > From: Bakshi, Arjun > > Sent: Thursday, November 2, 2017 9:38:48 PM > > To: discuss-gnuradio@gnu.org > > Subject: X310 with 2 WBX in full duplex > > > > > > Hi, > > > > > > I'm trying to get two Tx-Rx links running with an X310 with two WBX > > daughterboards in it. I've used multi-channel USRP source/sink blocks, > but > > I'm experiencing latency (L) errors with the connection, and then the > > application (GRC) hangs. I've attached an image of my USRP source/sink > > blocks. I'm connected to the X310 with a 1GB ethernet connection. > > > > > > Can anyone point out the reason/mistake? Also, is the sub-device spec > > correct? Followed instructions for WBX from here: > > https://www.ettus.com/content/files/kb/application_note_fron > tends_subdevices_antenna_ports.pdf > RX DSP Chain 1 Logic DDC ADC SMA RXB - Ettus Research > <https://www.ettus.com/content/files/kb/application_note_frontends_subdevices_antenna_ports.pdf> > www.ettus.com > Default Sub-Device and Antenna Specifications UHD will automatically > select a sub-device and antenna specification if they are not specified by > you. > > > > > My goal: > > > > I want to have a Tx-Rx link in freq F1 and another in freq F2 at the same > > time. One daughterboard TXes in F1 and RXes in F2, while other TXes in F2 > > and RXes in F1. Is this possible with the equipment I have? > > > > > > Thank you, > > > > > > AB > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > Discuss-gnuradio -- GNU Radio, a free software radio toolkit > <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> > lists.gnu.org > To see the collection of prior postings to the list, visit the > Discuss-gnuradio Archives. Using Discuss-gnuradio: To post a message to all > the list ... > > > > > >
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
