To whom it may concern: First, I am not an expert of USRP, so I could be wrong.
A few thoughts: 1. A USRP N200 does have two DACs / ADCs, but they are typically used for the I-Q sampling, so whether you can get two RX channels from a USRP N200 depends on the installed daughterboards. (Well, you can theoretically split the I channel and the Q channel, but I don't really see much benefit.) 2.I did not try manually decoding packets from the USRPs, so I could be wrong, but maybe you can LAN tap your USRP using a dumb hub if the passive listening is sufficient. (However, you probably have to write your own GNU Radio sources). 3. Yes, TCP and UDP are theoretically unreliable, but you really shouldn't lose too much packets when the connection is reliable and you are staying under the capability of your network hardare. In fact, USRP N200 *uses* UDP to communicate with your PC at approx. 800Mbps rate (for 25MS/s I-Q sampling), and it rarely drops a packet (I saw a few packet drops, but when and only when I used old NICs, switches, or cables). Regards, Kyeong Su Shin On Fri, Aug 25, 2017 at 1:14 AM, Claudio Cicconetti via USRP-users < usrp-users@lists.ettus.com> wrote: > Dear Munir, > Your experiment confirms my theory: you cannot drive a single USRP from > two applications. > > You need a custom application. I am no expert on Gnuradio, but I very > much doubt you can achieve your objective with it. You should try > writing a C/C++ application (or python with the new API if performance > is not a major concern). > > Claudio > > On 08/25/2017 09:44 AM, Muhammad Munir wrote: > > Dear Claudio, > > Thanks for the reply. > > I connected a single USRP with two PCs and tried to access USRP using two > > different host PCs. When a USRP is engaged with one host, the other can > not > > get access to USRP. It means, we can access USRP by a single host at a > > time. > > The problem with the solution you suggested is that Gnuradio support for > > communication between two applications is only through TCP or UDP which > is > > not reliable. I connected the application as given in figure. It gives > USRP > > underflow or overflow error. (UUUUUUUUUUUUUU or DDDDDDDDDDDD). > > > > Regards: > > Munir > > > > > > On Fri, Aug 25, 2017 at 12:16 PM, Claudio Cicconetti < > > cciccone...@mbigroup.it> wrote: > > > >> Dear Muhammad, > >> 1. Yes, it is possible to connect an N200 to a switch, then you can use > >> any PC connected to that as the host for the USRP device. Just make sure > >> the switch is GbE (1000 Mb/s), not Fast Ethernet (10/100 Mb/s). Note > >> that this approach has been discouraged by Ettus in the past for a > >> number of reasons, but it works in practice. > >> > >> 2. No, it is not possible for multiple applications to use the same USRP > >> device, regardless of whether they reside in the same host or in > >> different hosts in a LAN. > >> > >> If you really need to access the same USRP (any series) from two > >> applications, then you have to use a "broker": a single application > >> drives the USRP, then it dispatches/receives data via network or any > >> other mechanism (shared memory, whatever) to/from other applications, > >> possibly on different hosts. This solution is 100% in your hands: AFAIK > >> there are not examples from Ettus on this. > >> > >> Note: the N200 has a single ADC/DAC, therefore I am assuming you have in > >> mind some kind of TDD operation. > >> > >> Ciao, > >> Claudio > >> > >> On 08/25/2017 07:41 AM, Muhammad Munir via USRP-users wrote: > >>> Hi, > >>> The USRP N200 has two channels. I want data of each channel to two > >>> different computers (PCs). There is only one Ethernet connection is > >>> available with USRP. My questions are > >>> 1. Is it possible to connect a single USRP with two different PCs > >> connected > >>> on a same network through Ethernet switch? > >>> 2. Is it possible to stream two channels of USRP to two different PCs? > >>> Please Let me know the solution? > >>> > >>> Thanks in advance > >>> Muhammad Munir > >>> > >>> > >>> > >>> _______________________________________________ > >>> 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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