[Discuss-gnuradio] howto select subdev with USRP1

[Wolfgang Buesser]

Hi

I am having problems selecting the subdev with USRP1:

My USRP1 is populated with 2 LFRX and 2 LFTX.

I am trying the following code:

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#!/usr/bin/python                                                               
                                                                                
                                                                            

from gnuradio import gr
from gnuradio import uhd
from gnuradio.eng_option import eng_option


class build_block(gr.top_block):
    def __init__(self):
        gr.top_block.__init__(self)

        self.u_tx = uhd.usrp_sink("serial=47432785",uhd.stream_args('fc32'))

        self.u_tx.set_samp_rate(8.0e6)
        self.tx_src0 = 
gr.sig_source_c(self.u_tx.get_samp_rate(),gr.GR_CONST_WAVE,0, 1.0, 0)
        self.u_tx.set_center_freq(10e6)
#       self.u_tx.set_subdev_spec("A:AB",0)                                     
                                                                                
                                                                           


        self.connect (self.tx_src0, self.u_tx)


def main ():
    tb = build_block ()
    tb.start ()
    raw_input ('Press Enter to quit: ')

if __name__ == '__main__':
    main ()

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This way I get I- and Q- Signals out of TXB.
With the subdev_spec uncommented I get nothing - neither TXA, not TXB.
With self.u_tx.set_subdev_spec("B:AB",0) I again only get TXB.

What do I Have to configure to get signals only from TXA?

Thanks

Wolfgang