Transmit and receive at the same time using mimo_usrp

Hi List,

If have a special application were I use two USRP2 with XCVR2450.
Sometimes the two USRP2s transmit, sometimes they receive, but sometimes
one of them transmit and the other receives.

My understanding is that I will have to create to simple_usrp objects,
because with mimo_usrp either all usrps transmit or all of them receive.
Is this correct ?

BR/
Per