Advantech ADAM-5511 Manual page 174

com_232_install
Syntax:
int com_232_install(void)
Description:
Allocates the interrupt registers of the microprocessor for use by the
RS-232 port and sets the interrupt vector to the interrupt service
routine.
Parameter Description
None.
Return value:
integer; Installation status.
0 = Successful installation
1 = Drivers are already installed
Example:
void main()
{
int status;
status = com_232_install();
if( status ==0)
printf("\n The allocation of COM2 port (RS-232) is OK !");
else
exit(0);
}