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From: | Bakshi, Arjun |
Subject: | Re: [Discuss-gnuradio] X310 with 2 WBX in full duplex |
Date: | Fri, 3 Nov 2017 15:42:00 +0000 |
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 <address@hidden>
Sent: Thursday, November 2, 2017 10:21:52 PM To: Bakshi, Arjun Cc: address@hidden 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 <address@hidden> 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: address@hidden > 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_frontends_subdevices_antenna_ports.pdf
> > 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 > address@hidden > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> |
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