use Win32::SerialPort;
use strict;
use warnings;

$| = 1; #enable autoflush

my $PortName = "COM3";
my $sendData = "12345678";

### SERIAL PORT SETUP ###
my $PortObj = new Win32::SerialPort($PortName) or die "Can't open $PortName: $^E\n";
 $PortObj->error_msg(1);  # prints hardware messages like "Framing Error"
  $PortObj->user_msg(1);   # prints function messages like "Waiting for CTS"

$PortObj->baudrate(57600);
$PortObj->parity("none");
$PortObj->databits(8);
$PortObj->stopbits(1);
$PortObj->handshake("none");
$PortObj->write_settings or die "failed to write_settings";
 
my $count_out = $PortObj->write($sendData) or die "write failed: $^E";
 sleep(3);
$PortObj->close() || warn "\nClose failed\n";