SetXon Method

The SetXon method causes transmission to act as if an XON character has been received.  

BOOL SetXon(
  void  
);

Return Values   If the method succeeds, the return value is TRUE. If the port was not closed the return value is FALSE.
Remarks   This method works only when software flowcontrol (xon/xoff) operation is executed. How to execute this operation you can refer to InitString method.