how to login into qnx6 through extern terminal

I have a terminal(a diplay screen attached by a keyboard).I connect the
terminal to PC through serial port (com2).
I use stty to define the com2,make it as some as the terminal self
define(such as speed bit,odd bit,stop bit,and terminal style -ansi).
I think that through this define ,I can use the terminal login into qnx.But
in the terminal ,when I hit a key in terminal,nothing display
in the terminal ? what should I do?
My system is qnx 6.1.0.
how to define and config to use terminal in the serial port to login into