IEC 61131 is a standard for programmable controllers. IEC 61131-3 focusses on programming languages for industrial automation. With its worldwide support, it is independent of any single company. The PLCopen OPC UA Information Model maps the IEC 61131-3 software model to an OPC UA information model. This mapping assures that an IEC 61131-3 control program on different control platforms from different control suppliers is represented the same way. A visualization program used for different controllers running the same control program must only be configured once. The PLCopen OPC UA Information Model is based on OPC UA for Devices (DI). PLCopen also defines Function Blocks to use OPC-UA client functionality in an IEC61131-3 controller. With these Function Blocks a controller can exchange complex data structures horizontally with other controllers independently from fieldbus system or vertically with OPC-UA interfaces in an MES/ERP system in order to collect data or write new production orders to the cloud. It allows a production line to be independently active in combination with integrated OPC UA Security features. OPC-UA client functionality in a controller does not provide hard deterministic real time and so it’s not a deterministic fieldbus – but UA provides fast, secured communication providing modelling mechanism for information models.