[Discuss-gnuradio] usrp2 tune two different frequencies

[ematlis]

Hi all-

is it possible to tune the USRP2 to two different frequencies?  I can do 
this with the USRP1 and a LFRX daughterboard using usrp.tune twice:

# Ch 0
r = usrp.tune(self.u, 0, self.subdev[0], target_freq1)

# Ch 1
r = usrp.tune(self.u, 1, self.subdev[1], target_freq2)

to tune each DDC to a separate frequency.  However, it's not clear to me 
how to do this with the USRP2 since in the examples I saw there is no 
explicit mention of which subdevice is being tuned:

r = self.u.set_center_freq(target_freq1)

thanks for any suggestions.

eric