Open Access

The variety of technologies used in modern Building Automation Systems (BAS) calls for methods to support interoperability of the devices from different technologies and vendors. OLE for Process Control Unified Architecture (=OPC UA) provides the possibility to enable secure inter operability of devices with platform independence and efficient information model features. However, OPC has not found broad space in the world of building automation, yet. In this paper, results and experiences from a project are presented, where BACnet devices are mapped to OPC UA standard models. The values and controls are presented by the OPC UA server running on an embedded device. In this paper, we map the BACnet information models into the corresponding OPC UA information models. The actual data (in OPC UA form) of the BACnet devices can be accessed by connecting an OPC UA Clients to the OPC UA Server. This objective was be pursued by using as many available open-source projects as possible.