Transmission error

The python code i’m currently using for my transmitter passes data to
the
usrp by placing it in a vector source, then runing that source thru a
multiplier (for gain purposes) and then finally sincs the vector to the
usrp
(the python then sleeps to allow the transmission to finish before
proceeding). However everytime i get to that position in the program i
get
a set of characters on my screen in the form ‘uU’ and see nothing on
the
oscilliscope i’m using to test my transmission. Any suggestions as to
why
this happens? the packets are relatively small. They start as a series
of
110 U8 values converted to bits and then converted to a sample level
(samplerate/desired data rate) and passed to the usrp. Unfortunately
when
passed to the USRP this nets me the ‘uU’ error and kicks me out to the
next
round of the transmission.
-Garrett McGrath