Hi. I did eventually find out the main issue with my previous program not working. The Win32::SerialPort as presented does not work with 64 bit operation (Perl). However there is a fix provided at (as linked to by Discipulus):

https://rt.cpan.org/Public/Bug/Display.html?id=113337#txn-1691722
[download]

This fix basically increases the sizes of some parameters in referencing a module (the memory mapping involved with this process).

My current working program is:

#! C:\perl\bin\perl.exe

use strict;
use warnings;

use Win32::SerialPort;
use Time::HiRes qw(usleep);

my $port_name = 'COM5';
#my $config_file = 'setup.cfg';    # use this to configure from the fi
+le

my $port = new Win32::SerialPort( $port_name ) ||  die "Unable to open
+: $^E\n";    # $^E EXTENDED_OS_ERROR
                                             
#my $port = new Win32::SerialPort($port_name, $config_file) || die "Un
+able to open: $^E\n";

$port->handshake('none');     # none dtr rts xoff
$port->baudrate(38400);       # 19200 57600 1200 9600 115200 4800 600 
+2400 300 38400
$port->parity('none');        # space none odd even mark
#$port->parity_enable(1);       #      for any parity except "none"
$port->databits(8);           # 7 8
$port->stopbits(1);           # 2 1
$port->buffers(256, 256);
$port->read_interval(0);      #RI
$port->read_const_time(20);   #RC
$port->write_char_time(1);    #WM
$port->write_const_time(100); #WC

print "Write settings \n";
$port->write_settings || undef $port;

# A report out to this console
my $baud = $port->baudrate;
my $parity = $port->parity;
my $data = $port->databits;
my $stop = $port->stopbits;
my $hshake = $port->handshake;

print "B = $baud, D = $data, S = $stop, P = $parity, 
            H = $hshake\n";
            
# use the below to save the current configuration
# if ( $port ) { $port->save('setup.cfg') ; print "Serial Port OK \n" 
+};

# pack: used for assembling binary stuff
# my $status = pack('H2' * 6, 'ca', '00', '01', '00', '00', 'fe');

$port->write("ati"."\r");
#$port->write("ati\x0D\x0A");      # carriage return and line feed:  n
+o different
#$port->write("ate0"."\r");

usleep 0;

my $debug = 1;
my $cmd = " ";

while ($cmd ne "quit") {
    print "Input command: ";
    $cmd = <STDIN>;
    chomp $cmd;
    if ($cmd eq "quit") {next;}
    $port->write($cmd."\r");
    my $loop = 1;
    while( $loop ) {
        usleep(200000);         # 0.2 of a second
        my $response = $port->input;
        chomp $response;
        print $response;
        
        #my $responseHex = unpack ('H*', $response);
        #print $responseHex."\n";
         
        my $last = substr ( $response, -1 );    # get the last charact
+er
        if ($last eq ">") { $loop = 0; 
                             next; 
                          }
        print ".";
    }    
}
[download]

Regards JC.....

Did you follow my suggestion of reading the port settings (handshake, etc)? Make sure that the port is configured and "happy" - if not it won't send data. I would not introduce the complication of a config file at this early stage.

Again, trying running outside of Eclipse. That could make a difference.

please show the exact code that you are using for this testing.