Initially you may want to see, that some basic RF communication between your boards is running.
At first flash xmpl_radio_range_<board>.hex. This application sends every 500ms a frame and stays in receive mode for the remaining time between the transmissions.
If your radio Boards have LED's, LED1 flashes quickly indicating that a frame is transmitted and LED 2 toggles with each received frame.
If you have a board connected to a UART, you will see the following output.
.... todo: Screen ....
If nothing happens, that indicate that your setup is working correctly, go to the section Debugging a Setup from Scratch.