Industrial automation system comprising: at least two control devices (170, 171, 172); wherein each of the at least two control devices (170, 171, 172) is arranged for: executing an automation application (222, 232) that uses local IEC variables (225, 235); hosting an OPC UA server (223, 233) as an instance separate from the automation application (222, 232), the OPC UA server using OPC UA objects (227, 237), which objects (227, 237) are stored in an address space; mapping local IEC variables (225, 235) with OPC UA objects (227, 237); hosting a subscriber service separate from the OPC UA server (223, 233); hosting a publisher service separate from the OPC UA server (223, 233); and wherein the subscriber service is arranged for accessing the OPC server address space and storing in the address space OPC UA objects (227, 237) received from at least one publisher service to which the subscriber service is subscribed in accordance with a subscriber configuration; wherein the publisher service is arranged for accessing the OPC server address space and retrieving OPC UA objects (227, 237) to be published by the publisher service as in accordance with a publisher configuration. at least two control devices (170, 171, 172); wherein each of the at least two control devices (170, 171, 172) is arranged for: executing an automation application (222, 232) that uses local IEC variables (225, 235); hosting an OPC UA server (223, 233) as an instance separate from the automation application (222, 232), the OPC UA server using OPC UA objects (227, 237), which objects (227, 237) are stored in an address space; mapping local IEC variables (225, 235) with OPC UA objects (227, 237); hosting a subscriber service separate from the OPC UA server (223, 233); hosting a publisher service separate from the OPC UA server (223, 233); and wherein the subscriber service is arranged for accessing the OPC server address space and storing in the address space OPC UA objects (227, 237) received from at least one publisher service to which the subscriber service is subscribed in accordance with a subscriber configuration; wherein the publisher service is arranged for accessing the OPC server address space and retrieving OPC UA objects (227, 237) to be published by the publisher service as in accordance with a publisher configuration. executing an automation application (222, 232) that uses local IEC variables (225, 235); hosting an OPC UA server (223, 233) as an instance separate from the automation application (222, 232), the OPC UA server using OPC UA objects (227, 237), which objects (227, 237) are stored in an address space; mapping local IEC variables (225, 235) with OPC UA objects (227, 237); hosting a subscriber service separate from the OPC UA server (223, 233); hosting a publisher service separate from the OPC UA server (223, 233); and wherein the subscriber service is arranged for accessing the OPC server address space and storing in the address space OPC UA objects (227, 237) received from at least one publisher service to which the subscriber service is subscribed in accordance with a subscriber configuration; wherein the publisher service is arranged for accessing the OPC server address space and retrieving OPC UA objects (227, 237) to be published by the publisher service as in accordance with a publisher configuration.