The PHP ftp_pasv() function turns passive mode on or off.

<?php
// connect and login to FTP server
$ftp_server = 'ftp.example.com';

$ftp_conn = ftp_connect($ftp_server) or die('Could not connect to ' . $ftp_server);
$login = ftp_login($ftp_conn, $ftp_username, $ftp_userpass);

// turn passive mode on
ftp_pasv($ftp_conn, true);

$file = 'local-file.txt';

// upload file
if (ftp_put($ftp_conn, 'server-file.txt', $file, FTP_ASCII)) {
    echo 'File successfully uploaded';
}
else {
    echo 'Error uploading file';
}

// close connection
ftp_close($ftp_conn);
?>

// turns passive mode on and uploads a file to the FTP server

ftp_pasv(ftp_conn, pasv)