The KNX organization has been widely used in European countries, and has started to lead in intelligent home and building automation systems all over the world. In smart home and building automation systems, it has become the structure that determines system standards. In 2003 KNX standards were approved by the CENELEC (European Committee of Electrotechnical Standartisation) and entered into force. Thus, the EN50090 Standard series is built for home and building automation systems. The KNX standard has also been approved by CEN.