I did following: I made simple flow graph and used USRP source first with two channels and LFTX mboard. But the follwong error occurs:
File "/home/savi_ne/work/gnuradio/GRC/top_block.py", line 105, in __init__
self.uhd_usrp_source_0_0_1.set_center_freq(433900000, 1)
File "/usr/local/lib64/python2.6/site-packages/gnuradio/uhd/uhd_swig.py", line 1872, in set_center_freq
return _uhd_swig.uhd_usrp_source_sptr_set_center_freq(self, *args)
RuntimeError: vector::_M_range_check
When I tried with setting two mboards, with LFTX A channel subdevice in the first channel (B:A option_ and WBX on the second channel I get following error:
File "./top_block.py", line 101, in __init__
self.uhd_usrp_source_0_0_1.set_subdev_spec("A:0", 1)
File "/usr/local/lib64/python2.6/site-packages/gnuradio/uhd/uhd_swig.py", line 1831, in set_subdev_spec
return _uhd_swig.uhd_usrp_source_sptr_set_subdev_spec(self, *args, **kwargs)
RuntimeError: vector::_M_range_check
And as far as I have seen GRC doesn't put anything in the field device_addr for changing FPGA image.