Perhaps look at the RFNoC siggen block. You will need to add some component such as a block memory or fifo to store the samples on the fpga and then you will need a way to populate the memory and then play it out when desired.
Rob On Mon, Jul 30, 2018 at 3:49 AM Farnaz Chamanzadeh <farnaz.c...@gmail.com> wrote: > Dear Rob, > Thanks for your helpful response. The reason that we need to use a switch > is due to hour host hardware limits, which only have one 10GBE. > About the second remark in your email, do you have an example or a > reference where a similar case was implemented which we can use as a > guideline for our implementation? > > Best regards, > Farnaz > > On Thu, Jul 26, 2018 at 7:52 PM, Rob Kossler <rkoss...@nd.edu> wrote: > >> Hi Farnaz, >> A couple of remarks and questions >> - Remark 1: in order to get 200 MS/s transmit streaming, you will NEED to >> have the samples on the USRP. The host-to-USRP streaming does not work at >> 200 MS/s for the transmit case (unless something has recently changed). The >> host-to-USRP max for transmit is 100 MS/s per channel >> - Remark 2: that leads into your question about having the samples stored >> on the USRP rather than streamed from host. This is not presently a >> capability, but can be added with some modest FPGA work. I have been >> desiring such capability for a couple of years - I hope that Ettus adds >> such capability in the future. >> - Question 1: why do you plan to use a 10gbe switch with a single >> connection to the host PC? Why not have multiple 10Gbe links at the PC >> which connect to each USRP individually. A NIC such as Intel XL-710 >> provides 4 10gbe links. >> >> Rob >> >> >> On Thu, Jul 26, 2018 at 12:13 PM Farnaz Chamanzadeh via USRP-users < >> usrp-users@lists.ettus.com> wrote: >> >>> Dears, >>> >>> To be more specific, we want to control multiple USRPs with one (remote) >>> computer. We would like to stream known and periodic signal from each USRP. >>> The sequence on each USRP is unique and is different from other USRPs. >>> >>> Since the samples from each USRP are known, it would be more >>> convenient if we can generate the samples once and preferably store them >>> locally on each USRP. In this configuration, we want to use the host >>> computer to send control commands to the USRPs specifying when each of them >>> must transmit its specific samples. The USRPs are assumed to be >>> synchronized, so the control commands from the host will generate a TDMA >>> scheme. Each USRP will start signal transmission upon receiving the control >>> command from the host computer. I would like to know that: >>> >>> 1. Is it possible to store the samples on the USRPs? or should we stream >>> the samples from the host computer to the USRPs for each transmission? >>> 2. Can we use the full bandwidth and 200MS/s in this setup? >>> 3. After knowing the answer to the previous question, I would like to >>> know how we can implement it? do you happen to have a demo or an example >>> that can guide us in this implementation? >>> >>> Best, >>> Farnaz >>> >>> >>> >>> >>> >>> >>> On Wed, Jun 27, 2018 at 4:50 AM, Michael West <michael.w...@ettus.com> >>> wrote: >>> >>>> Hi Farnaz, >>>> >>>> To clarify and expand on Marcus' comments, the answer is maybe. You >>>> can do burst captures and transmissions at full rate and you can even use >>>> timed commands to synchronize them, but there are limitations. If you can >>>> describe in more detail what you want to do, we can more clearly tell you >>>> if it is possible. How many channels do you plan to do simultaneously? >>>> How many 10 GbE connections between the host and switch? How many 10 GbE >>>> connections between each USRP and the switch? >>>> >>>> There is buffering of the TX samples on the X310 and it is >>>> configurable. The current default is 32 MB. The DRAM is a total of 1 GB, >>>> and it can be divided up however necessary. >>>> >>>> Regards, >>>> Michael >>>> >>>> On Mon, Jun 25, 2018 at 12:23 PM, Marcus Müller via USRP-users < >>>> usrp-users@lists.ettus.com> wrote: >>>> >>>>> Dear Fernaz, >>>>> >>>>> you can't cheat 10Gig bandwidth! If you time-share any medium, then >>>>> it's bandwidth must be shared. Since ethernet is de facto a timesharing >>>>> thing, anyway, no, this won't work: >>>>> Since you need to push through all the data through a single 10GigE >>>>> connection, your 10 gigabits per second need to be divided along *all >>>>> simultaneously operating* USRPs. So, if you have, say 10 USRPs, and all >>>>> should be working at the same time, you've only got 1 gigabit per >>>>> second per USRP, which limits you to about 25 MSample/s per USRP. It's >>>>> really the same principle as a single internet access being shared by >>>>> all people attached to the same router. >>>>> >>>>> Now, if these USRPs *don't* have to transmit all at the same time, then >>>>> more is possible. >>>>> >>>>> > Also, does anyone know if it is possible to store the samples on the >>>>> transmit USRPs? >>>>> >>>>> I'll go with a: no, at least probably not like you hope it is. Can you >>>>> elaborate on your use case? Maybe we can help you if we better >>>>> understand what you're trying to implement, from a bit of distance? >>>>> >>>>> Best regards, >>>>> Marcus >>>>> >>>>> On Mon, 2018-06-25 at 20:32 +0200, Farnaz Chamanzadeh via USRP-users >>>>> wrote: >>>>> > Dear all, >>>>> > >>>>> > I want to connect multiple USRP X310 to one host PC and control them >>>>> > all from that Pc, using one 10Gigabit Ethernet switch. My question >>>>> > is that if it is possible to stream from each USRP in a different >>>>> > time slot using the full bandwidth and 200MS/s in a setup similar to >>>>> > the picture below? >>>>> > >>>>> > Also, does anyone know if it is possible to store the samples on the >>>>> > transmit USRPs? >>>>> > >>>>> > >>>>> > >>>>> > >>>>> > Best, >>>>> > Farnaz >>>>> > >>>>> > _______________________________________________ >>>>> > USRP-users mailing list >>>>> > USRP-users@lists.ettus.com >>>>> > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>>> _______________________________________________ >>>>> USRP-users mailing list >>>>> USRP-users@lists.ettus.com >>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>> >>>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >> >
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