Re: Re[Discuss-gnuradio] ceiving packets using 2 daughterboads in 2 framer sink didn't work correctly.

[Eric Blossom]

On Mon, Mar 23, 2009 at 04:39:14AM -0700, Ling Huang wrote:
> 
> Hi, I have posted my question a few days ago, but no one answer my question.
> Maybe I didn't make my question clear. If there are any puzzle of my
> statements, please let me know.
> 
> Here is my staff,
> I use rfx400 and rfx2400 multi daughterboads on one USRP to receive or
> transmit at the same time.I modified the codes of gnuradio-examples/digital
> to do the work. 
> The transmit part worked well. But the receive path didn't work correctly.
> Only the framer_sink of rfx2400 side work. The other side of rfx400 can
> receive the signal(I set --log-rx-power, and see the rfx400 did receive the
> signal.) But the framer_sink of rfx400 didn't work.

If I understand what you're trying to do (One USRP using both the
rfx400 and rfx2400 at the same time, and both of them receiving and
transmitting using Auto TR and temporally the two streams are
independently of each other), I don't think you can make that work
without a substantial overhaul of the host, FX2 and FPGA code.

Why this is so, is that when using two channels, the two channels are
interleaved 1:1 in both the Tx and Rx directions.  There is in effect
only a single Tx queue and a single Rx queue in the FPGA.  When using
Auto TR, that single Tx queue controls whether both daugherboards are
in Tx or Rx mode.

If I've misunderstood what you're trying to do, please ask again.
If I did understand your situation, I suggest using two USRPs, one
with the rfx400 and the other with the rfx2400.

Eric