i done something like your long time ago, i can't sent the data as the pic read it from A/D converters, i needed to transform it to an char array or a string.
i was using a 8bit A/D, then i convert an FF from it to an "255" string. i needed to put a token before this string because i was controlling two signals, then i received something like this "A120B056A125B60..." a continuos streaming data. Looking for the rigth token i made the conversions to unit values (ºC & RPM) in LabView...