[Discuss-gnuradio] io_type configuration for uhd.single_usrp_source

 Dear all,

I am using USRP N200 +UHD with the LFRX daughter board to detect a 100kHz coded sinusoid wave then down convert the signal to baseband to see the coding method. The flow graph I am using is:

u2=uhd.single_usrp_source(device_addr="addr=192.168.10.2",io_type=uhd.io_type_t.COMPLEX_INT16,num_channels=1) decim_coeffs = gr.firdes.low_pass(1.0,
                              60e3,     #sampling frequency
                              30e3,        #cutoff frequency
                              .1e3,
                              gr.firdes.WIN_BLACKMAN)
decim_filter = gr.fir_filter_fcc(1,decim_coeffs)
dst=gr.file_sink(gr.sizeof_gr_complex, filename)
connect(u2, decim_filter,dst)

I am curious about how to configure the io_type_t for the receiver? COMPLEX_INT16 represents complex signed integer, 16-bit integer. I found only this io type could match the type provided for the input of fir_filter. Do I misunderstand something for this io type selection?

Really appreciate any of your help

Thanks,
Yan