As an Open Standard, OPC UA is based on standard Internet technologies, such as TCP/IP, HTTP, Ethernet and XML. OPC UA provides a set of services (see OPC 10000-4) and a basic information model framework.

As an Extensible Standard, OPC UA provides an information model framework which can expose vendor defined information in a standard way. More importantly all OPC UA Clients are expected to be able to discover and use vendor defined information. This means OPC UA users can benefit from the economies of scale that come with generic visualisation and interface applications. This specification is an example of an OPC UA InformationModel designed to meet the needs of developers and users in the offshore oil and gas industry.

OPC UA Clients can be any consumer of data, from devices / controllers on the network; browser based thin clients and higher level ERP systems. OPC UA applications are platform and development language dependant. The full scope of OPC UA applications are illustrated in Figure 1. For this companion specification the typical communication would be device to device or device to SCADA type communications.

Figure 1 – The of OPC UA within an Enterprise

OPC UA provides a robust and reliable communication infrastructure having mechanisms for handling lost messages, recovering from network interruptions, etc. With its binary encoded data it offers a high-performance data exchange solution. Security is built into OPC UA, security requirements are becoming more and more important as, increasingly, environments are connected to the office network or the internet and attackers are starting to focus on automation systems