What the relation between the amplitude set in program and voltage of the received signal

Dear all,

I’m using USRP1 with LFRX plug-in. Could you please tell me what’s the
relation between the amplitude that we set in program and the voltage of
the received signal. For instance, if I receive a signal whose amplitude
read from the received data file is 2000 units, what’s the corresponding
voltage of this 2000 units?

Really appreciate any of your reply

Yan