REG:benchmark_tx and rx not work in Ettus usrpN200

GNU Radio
1

Hi,

I am working with Ettus UsrpN200 board. I am usig gnuradio 3.5.1
version.
I used loop back and it worked perfectly but when I used Usrp board it
is not working.

I used following commands to run

./benchmark_tx -f 2400e6 -m dbpsk -r 50e3 -S 4 -v

./benchmark_rx -f 2400e6 -m dbpsk -r 50e3 -S 4 -v

If anyone faced this problem and solved it.Please let me know.

Thank You.

M.G.Praveen Kumar