Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Eric Blossom
On Thu, Apr 16, 2009 at 09:05:50PM +, Juha Vierinen wrote: > > How about overflows. What is the probability that a USRP2 will drop > samples guring 24 h of 10 MHz receiving when connected directly to a > computer? I guess there is no mechanism that guarantees that the data > is delivered, but

Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Juha Vierinen
>> Similar issues exist on the transmit side. Ok. > Actually they are quite different.  When we assert flow control, we flow > control _everything_ upstream between the USRP2 and the host.  Unless > you want your network to die, die, die, don't put a switch between > the USRP2 and the host if you

Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Eric Blossom
On Thu, Apr 16, 2009 at 08:34:25AM -0700, Johnathan Corgan wrote: > > Similar issues exist on the transmit side. Actually they are quite different. When we assert flow control, we flow control _everything_ upstream between the USRP2 and the host. Unless you want your network to die, die, die, d

Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Eric Blossom
On Thu, Apr 16, 2009 at 03:13:51PM +, Juha Vierinen wrote: > > Off topic: We have been playing around with my USRP2 and it seems very > nice. I noticed that even though the FAQ strongly discourages > connecting the USRP2 to your main network, it does actually work. We > have a fairly large LAN

[Fwd: Re: [Discuss-gnuradio] Timestamps, data rates]

2009-04-16 Thread Douglas Geiger
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Forgot to copy the list: Eric Blossom wrote: > On Tue, Apr 14, 2009 at 02:19:38PM -0500, Douglas Geiger wrote: > > Doug, > > I wouldn't expect the time stamps in the streams to start at the same > point (the start_rx_streaming command doesn't accept a

RE: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Ben Buley
lf Of Juha Vierinen Sent: Thursday, April 16, 2009 11:14 AM To: discuss-gnuradio@gnu.org; Eric Blossom Subject: Re: [Discuss-gnuradio] Timestamps, data rates > I wouldn't expect the time stamps in the streams to start at the same > point (the start_rx_streaming command doesn't a

Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Johnathan Corgan
On Thu, 2009-04-16 at 15:13 +, Juha Vierinen wrote: > How accurate is sync_to_pps? Can you do MIMO with just sync_to_pps > (assuming your cables are equal length)? Yes. Two USRP2s synced to the same 10 MHz reference and PPS will have sampling times accurate to the PPS arrival time, and will

Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-16 Thread Juha Vierinen
> I wouldn't expect the time stamps in the streams to start at the same > point (the start_rx_streaming command doesn't accept a "start at > time T argument).  I would expect that there is a constant delta_t > between subsequent frames, and that that delta_t would be the same for > both of the USRP

Re: [Discuss-gnuradio] Timestamps, data rates

2009-04-15 Thread Eric Blossom
On Tue, Apr 14, 2009 at 02:19:38PM -0500, Douglas Geiger wrote: > I'm running some experiments with my two USRP2's - as I want to get > synchronized samples out of them. I have the clock's locked to my > external 10Mhz, and they sync_to_pps correctly (i.e. the timestamp > resets on the next PPS).

[Discuss-gnuradio] Timestamps, data rates

2009-04-14 Thread Douglas Geiger
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 I'm running some experiments with my two USRP2's - as I want to get synchronized samples out of them. I have the clock's locked to my external 10Mhz, and they sync_to_pps correctly (i.e. the timestamp resets on the next PPS). However, the difference