use Device::Modem;

my $modem = new Device::Modem( port => '/dev/ttyS1' );

if( $modem->connect( baudrate => 9600 ) ) {
     print "connected!\n";
} else {
     print "sorry, no connection with serial port!\n";
}
# when program running at this line, return connected!,

$modem->attention();          # send `attention' sequence (+++)

$modem->dial('02270469012');  # dial phone number
#when program running at this line was halted