Re: [Discuss-gnuradio] Full duplex and half duplex doesnot work

[Eric Blossom]

On Tue, Jan 19, 2010 at 06:00:43AM -0800, abbasi9999 wrote:
> 
> Hi all,
> Before i start telling about my problem, i want to mention that i have
> already read the post named "help: cannot send after transport endpoint
> shutdown" which is very close to my problem but i could not solve it.
> 
> I'm trying to transmit from the usrp  port A, and then make it receive at
> the same port using "Auto T/R" which i expressed by typing "-v" (isn't it
> correct) after the benchmark.
> but some time it works and most of the times its not (not stable), when its
> not working it shows me the following error:

From the backtrace below, it appears that you already have the source
open, or you're running something else that has the source open, or
you opened it earlier and didn't close it, or still have a live python
to the earlier instance.

Half-duplex vs full-duplex is orthogonal to this issue.  Likewise,
Auto T/R has nothing to do with the error below.  With either full or
half duplex you would most likely open the source and sink once each
at the beginning of the program, then go about your business.

Eric


> address@hidden:~/Documents/abbasi/programmitx.py -f 1200000000 -m dbpsk -v
> --tx-amplitude=0.08 -T A
> >>> gr_fir_ccf: using SSE
> 
> Modulator:
> bits per symbol:     1
> Gray code:           True
> RRC roll-off factor: 0.35
> Tx amplitude     0.08
> modulation:      dbpsk_mod
> bitrate:         100kb/s
> samples/symbol:    2
> USRP Sink: A: Flex 1200 Tx MIMO B
> Requested TX Bitrate: 100k Actual Bitrate: 125k
> Warning: failed to enable realtime scheduling
> address@hidden:~/Documents/abbasi/programmirx.py
> -f 1200000000 -m dbpsk -v
> >>> gr_fir_ccf: using SSE
> 
> Demodulator:
> bits per symbol:     1
> Gray code:           True
> RRC roll-off factor: 0.35
> Costas Loop alpha:   1.50e-01
> Costas Loop beta:    5.62e-03
> M&M mu:              0.50
> M&M mu gain:         1.00e-01
> M&M omega:           2.00
> M&M omega gain:      2.50e-03
> M&M omega limit:     0.01
> 
> Receive Path:
> modulation:      dbpsk_demod
> bitrate:         100kb/s
> samples/symbol:    2
> usrp_open_interface:usb_claim_interface: failed interface 2
> could not claim interface 2: Device or resource busy
> usrp_basic_rx: can't open rx interface
> Traceback (most recent call last):
>   File "mybenchmark_rx.py", line 112, in <module>
>     main()
>   File "mybenchmark_rx.py", line 101, in main
>     tb = my_top_block(demods[options.modulation], rx_callback, options)
>   File "mybenchmark_rx.py", line 45, in __init__
>     self.rxpath = usrp_receive_path.usrp_receive_path(demodulator,
> rx_callback, options) 
>   File
> "/home/onur/Documents/abbasi/programming/examples/digital/usrp_receive_path.py",
> line 68, in __init__
>     self._setup_usrp_source(options)
>   File
> "/home/onur/Documents/abbasi/programming/examples/digital/usrp_receive_path.py",
> line 73, in _setup_usrp_source
>     self.u = usrp_options.create_usrp_source(options)
>   File
> "/home/onur/Documents/abbasi/programming/examples/digital/usrp_options.py",
> line 88, in create_usrp_source
>     gain=options.rx_gain,
>   File
> "/home/onur/Documents/abbasi/programming/examples/digital/generic_usrp.py",
> line 144, in __init__
>     _generic_usrp_base.__init__(self, **kwargs)
>   File
> "/home/onur/Documents/abbasi/programming/examples/digital/generic_usrp.py",
> line 63, in __init__
>     except: raise Exception, 'Failed to automatically setup a usrp device.'
> Exception: Failed to automatically setup a usrp device.
> address@hidden:~/Documents/abbasi/programming/examples/digital$ 
> 
> ON THE OTHER HAND: 
> when i try the full duplex (use a slot from block A as transmitter and slot
> from block B as receiver) it also doesnot work. it will not be able to setup
> the interface.
> 
> i appreciate your  help,
> regards,