Hi guys, I know, the answer is probably easy, but I can not get this to work. I am trying to communicate with satellite modem using serial port. I am sendng command to the modem and wait for "OK" response, for some rason "OK" is not recognized ( it is printed in terminal window just fine). Here is a code: 
#!/usr/bin/perl
use strict;
use warnings;
use Device::SerialPort;

my $PORT = "/dev/ttyUSB0";
my $serialData;
my $tx;
my $rx;

my $ob = Device::SerialPort->new($PORT) || die "Can't Open $PORT: $!";
$ob->baudrate(115200) || die "failed setting baudrate";
$ob->parity("none") || die "failed setting parity";
$ob->databits(8) || die "failed setting databits";
$ob->handshake("none") || die "failed setting handshake";
$ob->write_settings || die "no settings";
$| = 1;

$tx = $ob->write("AT&K0\n");
 do
    {        
        $rx = $ob->read(255);        
        chomp $rx;
        print $rx;    
    }

    until ($rx =~ m/OK/);
    print "OK received\n";

[download]
When I try to emulate satellite modem and sent OK response to my program it is still not recognized. When I change line until ($rx =~ m/OK/); to until ($rx =~ m/O/);("OK" changed to just one character "O" )it is recognized with no trouble. Any idea what is the problem?? Thanks in advance Robert OK, it looks like the issue was with Hyperterminal on win XP that I used aas emulator. I swich to Linux and used perl script as emulator and things are moving as expected. Thanks like always, Robert

In reply to Serial port - again by rkrasowski

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