in reply to Virtual COM port write

Please wrap your text in <p> and your code in <c> tags so it's readable.

A few things to try:

1. Check the return value of write_settings(): $PortObj->write_settings or die "failed to write_settings";

2. Turn off handshake: $PortObj->handshake("none");

3. Check the return value of write():

my $count_out = $PortObj->write($sendData);
warn "write incomplete\n" if $count_out != length($sendData);

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4. Wait a little while before closing the port - add a sleep(3); before $PortObj->close(). (Note: Although this may not be needed, a quick skim of the module's docs don't make it clear whether write() is blocking or not.)

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Re^2: Virtual COM port write
by jismake (Initiate) on Apr 20, 2014 at 12:00 UTC

    Not so lucky yet. I got following error Use of uninitialized value $count_out in numeric ne (!=) at test2.pl line 22. write incomplete

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      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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[d/l]
[select]
        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]

        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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