[Discuss-gnuradio] What is MIMO B?

[Luis Simoes]

Hi all,

I've implemented an application script to cover both ISM bands 433 MHz and 
2.4GHz. For that purpose I connect a Flex 2400 (RXA/TXA) and a Flex 400 
(RXB/TXB) on a USRP Rev 3 motherboard. Everything goes well. But if I connect 
a USRP rev 4.1 or 4.2 with the same d'board configuration to the USB-Bus, the 
python script prints out:

Using RX d'board B: Flex 400 Rx MIMO B
Using TX d'board B: Flex 400 Tx MIMO B

The script runs normal but no packet is received and no packet is send (no 
packet is arriving at another receiver (No Gnuradio receiver).
If the USRP rev 3 is used the print out is:
 
Using RX d'board B: Flex 400 Rx MIMO B
Using TX d'board B: Flex 400 Tx MIMO B

and packets are received and sent. The print output is obtained by 'print 
"Using TX d'board %s" % (self.subdev.side_and_name(),)'. Where comes this 
MIMO B difference comes from? Is this the reason why the application runs 
with one board and not with the other? How can I solve the problem?

Ah, before I forget it. Perhapes this could help you to give me an answer. If 
I run usrp_fft.py from the examples, I get a 'Failed to tune to initial 
frequency' in the status bar of the application window. If I try to introduce 
a frequency, the shell outputs:

...
File "/usr/local/lib/python2.4/site-packages/gnuradio/usrp.py", line 184, in 
tune
    return tune(self, chan, subdev, target_freq)
  File "/usr/local/lib/python2.4/site-packages/gnuradio/usrp.py", line 122, in 
tune
    ok, baseband_freq = subdev.set_freq(target_freq)
  File "/usr/local/lib/python2.4/site-packages/gnuradio/db_flexrf.py", line 
174, in set_freq
    R, control, N, actual_freq = self._compute_regs(freq)
  File "/usr/local/lib/python2.4/site-packages/gnuradio/db_flexrf.py", line 
392, in _compute_regs
    assert self.B_DIV >= self.A_DIV
AssertionError

Please, help me...  I am very grateful for every kind of help
Thank you guys!

Luis Simoes