Question about data using read_comple_binary.m

Hi,

I add self.file_sink to benchmark_ofdm_tx.py

self.file_sink = gr.file_sink(gr.sizeof_gr_complex, “filename.dat”)
welf.connect(sef.txpath, self.file_sink)

and looked at the data with read_complex_binary.m
However I am confused with units of x and y axis.
for exameple, if I get 2.5e6 for total x value, can I divided it by 64M
for
translate into exact time(second)?
also, using rfx2400 and how can I get dB of y axis? I am confused
between
amplitude options and real amplitude.
Thank you.

James,