Vaillant VRF Interface device that allows commercial and industrial air conditioners to be integrated into the KNX bus system. All the controls required by the end user can be made through this device. It keeps records in case of problems that may occur. It includes logic and converter interfaces in order to meet the extra needs in the field. For control flexibility, many objects are available in both bit and byte control and feedback objects. Special operating modes have been added for user comfort.