Unable to receive anything on receiver window!

Hey

I am working on USRP N200 with RFX2400. My set up includes two USRPs
connected to two computers. I want them to communicate using
uhd_benchmark_tx/rx.py codes. Initially I set up my receiver side by
running
uhd_benchmark_rx.py and it’s done! The I shift to transmitter side and
run
uhd_benchmark_tx.py. It starts to transmit ( it is shown on window as
… ) but I cannot receive anything
on
receiver window. So, my Question is what I am transmitting is correct or
not
? If yes, then why not I am able to receive anything on receiver side.
This is how it looks on both the sides.

RECEIVER :

aravind@COE-2X85V91:~/gnuradio/gnuradio-examples/python/uhd_benchmark$
./uhd_benchmark_rx.py -m gmsk -r 500k -v -S 2 --rx-freq=242M -F 10
linux; GNU C++ version 4.4.5; Boost_104200; UHD_003.001.002-ba0e3c8

receiver:
– Opening a USRP2/N-Series device…
– Current recv frame size: 1472 bytes
– Current send frame size: 1472 bytes
– mboard0 is MIMO master

UHD Warning:
Unable to set the thread priority. Performance may be negatively
affected.
Please see the general application notes in the manual for
instructions.
EnvironmentError: OSError: error in pthread_setschedparam
RX antenna: TX/RX
USRP Source: <gr_block gr uhd usrp source (2)>
Samplerate: 250000.0

UHD Warning:
The hardware does not support the requested RX frequency:
Target frequency: 242.000000 MHz
Actual frequency: 2342.000000 MHz

UHD Warning:
The hardware does not support the requested RX frequency:
Target frequency: 242.000000 MHz
Actual frequency: 2342.000000 MHz

gr_fir_fff: using SSE
bits per symbol = 1
M&M clock recovery omega = 2.000000
M&M clock recovery gain mu = 0.175000
M&M clock recovery mu = 0.500000
M&M clock recovery omega rel. limit = 0.005000
frequency error = 0.000000

Receive Path:
modulation: gmsk_demod
bitrate: 500kb/s
samples/symbol: 2.0000
Warning: Failed to enable realtime scheduling.

TRANSMITTER:

aravind@COE-CW85V91:~/gnuradio/gnuradio-examples/python/uhd_benchmark$
./uhd_benchmark_tx.py -m gmsk --size=100 -M 1 -r 500k --tx-amplitude=0.5
-v
-S 2 --tx-freq=242M -F 10
linux; GNU C++ version 4.4.5; Boost_104200; UHD_003.001.002-5239879

sender:
– Opening a USRP2/N-Series device…
– Current recv frame size: 1472 bytes
– Current send frame size: 1472 bytes

UHD Warning:
The recv buffer could not be resized sufficiently.
Target sock buff size: 50000000 bytes.
Actual sock buff size: 131071 bytes.
See the transport application notes on buffer resizing.
Please run: sudo sysctl -w net.core.rmem_max=50000000

UHD Warning:
The recv buffer could not be resized sufficiently.
Target sock buff size: 50000000 bytes.
Actual sock buff size: 131071 bytes.
See the transport application notes on buffer resizing.
Please run: sudo sysctl -w net.core.rmem_max=50000000
– mboard0 is MIMO master

UHD Warning:
Unable to set the thread priority. Performance may be negatively
affected.
Please see the general application notes in the manual for
instructions.
EnvironmentError: OSError: error in pthread_setschedparam
TX antenna: TX/RX
USRP Sink: <gr_block gr uhd usrp sink (2)>
sampling frequency: 1M

UHD Warning:
The hardware does not support the requested TX frequency:
Target frequency: 242.000000 MHz
Actual frequency: 4442.000000 MHz

UHD Warning:
The hardware does not support the requested TX frequency:
Target frequency: 242.000000 MHz
Actual frequency: 4442.000000 MHz

gr_fir_fff: using SSE
bits per symbol = 1
Gaussian filter bt = 0.35
Tx amplitude 0.5
modulation: gmsk_mod
bitrate: 500kb/s
samples/symbol: 2.0000
Warning: failed to enable realtime scheduling
…U…

Thanks in advance

On Tue, 2011-07-26 at 12:22 -0400, saketh kumar wrote:

receive anything on receiver side.
This is how it looks on both the sides.

Well, my first guess is that it could be because you’re transmitting and
receiving 2GHz apart. Take a closer look at those warnings. The
frequencies you are trying to use (242MHz) are far outside the range
your daughterboard supports.

–n