TX and RX on same board

I am using a RFX900 daughter board. I have tested the TX and RX
functionality separately and it works. I now want to do both
transmission and reception simultaneously from a single daughterboard on
a single usrp(both TX and RX are quadrature;I-Q).

what changes are required?(is this even possible?) I use only c++ and
the usrp_standard_tx and usrp_standard_rx classes only. Both TX and RX
need the same same frequency.

thanks in advance