in reply to Re^2: Virtual COM port write
in thread Virtual COM port write

That means write() returned undef, which means the write failed entirely. Try checking if $^E contains a useful error message: my $count_out = $PortObj->write($sendData) or die "write failed: $^E";

Try $PortObj->error_msg(1); $PortObj->user_msg(1); right after new() as shown in the module's docs.

Make sure that your handshake really is none, that depends on how the other side of the serial connection is configured.

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Re^4: Virtual COM port write
by jismake (Initiate) on Apr 20, 2014 at 13:05 UTC 
    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 $Por
+tName: $^E\n";
 $PortObj->error_msg(1);  # prints hardware messages like "Framing Err
+or"
  $PortObj->user_msg(1);   # prints function messages like "Waiting fo
+r 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";

    [download]
    now i have the following error "write failed:the handle is invalid at test2.pl line 23." Other info : iam using Virtual serial port driver 7.2 by eltima software. i use a tool called teraterm where i can send data on one port and receive on other port without any issues. but perl gives the problem :( thanks for your prompt response. jis
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[d/l]
Re^4: Virtual COM port write
by jismake (Initiate) on Apr 22, 2014 at 07:49 UTC

    the issue is resolved. iuninstalled strawberry 64 bit on windows 7 - 64 bit. and installed strawbettry 32 bit on windows 7-64 bit it worked then.. strange! <\p> thanks jis

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