Minecraft RCon Class

<?php
class MinecraftRconException extends Exception
{
    // Exception thrown by MinecraftRcon class
}

class MinecraftRcon
{
    /*
     * Class written by xPaw
     *
     * Website: http://xpaw.ru
     * GitHub: https://github.com/xPaw/PHP-Minecraft-Query
     *
     * Protocol: https://developer.valvesoftware.com/wiki/Source_RCON_Protocol
     */

    // Sending
    const SERVERDATA_EXECCOMMAND    = 2;
    const SERVERDATA_AUTH           = 3;

    // Receiving
    const SERVERDATA_RESPONSE_VALUE = 0;
    const SERVERDATA_AUTH_RESPONSE  = 2;

    private $Socket;
    private $RequestId;

    public function __destruct( )
    {
        $this->Disconnect( );
    }

    public function Connect( $Ip, $Port = 25575, $Password, $Timeout = 3 )
    {
        $this->RequestId = 0;

        if( $this->Socket = FSockOpen( $Ip, (int)$Port ) )
        {
            Socket_Set_TimeOut( $this->Socket, $Timeout );

            if( !$this->Auth( $Password ) )
            {
                $this->Disconnect( );

                throw new Exception( "Authorization failed." );
            }
        }
        else
        {
            throw new Exception( "Can't open socket." );
        }
    }

    public function Disconnect( )
    {
        if( $this->Socket )
        {
            FClose( $this->Socket );

            $this->Socket = null;
        }
    }

    public function Command( $String )
    {
        if( !$this->WriteData( self :: SERVERDATA_EXECCOMMAND, $String ) )
        {
            return false;
        }

        $Data = $this->ReadData( );

        if( $Data[ 'RequestId' ] < 1 || $Data[ 'Response' ] != self :: SERVERDATA_RESPONSE_VALUE )
        {
            return false;
        }

        return $Data[ 'String' ];
    }

    private function Auth( $Password )
    {
        if( !$this->WriteData( self :: SERVERDATA_AUTH, $Password ) )
        {
            return false;
        }

        $Data = $this->ReadData( );

        return $Data[ 'RequestId' ] > -1 && $Data[ 'Response' ] == self :: SERVERDATA_AUTH_RESPONSE;
    }

    private function ReadData( )
    {
        $Packet = Array( );

        $Size = FRead( $this->Socket, 4 );
        $Size = UnPack( 'V1Size', $Size );
        $Size = $Size[ 'Size' ];

        // TODO: Add multiple packets (Source)

        $Packet = FRead( $this->Socket, $Size );
        $Packet = UnPack( 'V1RequestId/V1Response/a*String/a*String2', $Packet );

        return $Packet;
    }

    private function WriteData( $Command, $String = "" )
    {
        // Pack the packet together
        $Data = Pack( 'VV', $this->RequestId++, $Command ) . $String . "\x00\x00\x00";

        // Prepend packet length
        $Data = Pack( 'V', StrLen( $Data ) ) . $Data;

        $Length = StrLen( $Data );

        return $Length === FWrite( $this->Socket, $Data, $Length );
    }
}