well easy thing go first , if he use vb "mscommand" to recieved data , only thing he need to modify is put the txd & rxd together in pc com port side, make a vb program to send out data via pc com port and another vb program recieved data from the same com pot if data can be show correctly mean he got a pc terminal ready , any other error should be 52 side (both txd or rxd) then make this forum be helpful.
and still if he got problem in this vb program , which is mean , he can go nowhere for the project !