OPC UA (Unified Architecture) and OPC DA (Data Access) are industrial automation and control system communication protocols. They are both members of the OPC (Open Platform Communications) family of protocols, but their functionality and use cases differ significantly.
In the late 1990s, OPC DA, the original OPC protocol, was developed. It is based on the Microsoft DCOM (Distributed Component Object Model) technology and is intended to provide process control and automation systems with real-time data access. OPC DA is a simple, user-friendly protocol that facilitates data exchange between various devices and applications. It is frequently employed in manufacturing and process control systems, building automation, and innovative grid applications.
OPC UA, on the other hand, is a more recent protocol developed to address some of OPC DA’s limitations. It is a platform-independent, service-oriented protocol that enables the exchange of data between devices and applications securely and reliably. OPC UA is designed to be more flexible and scalable than OPC DA, and it supports a greater variety of data types and has a more robust data model. OPC UA also permits the creation of custom data models and can manage more complex data structures.
The level of security they offer is one of the primary differences between OPC UA and OPC DA. OPC UA is regarded as more secure than OPC DA because it supports encrypted communication and digital certificates. In contrast, OPC DA has limited security features and relies on an external security mechanism for protection.
The level of interoperability between various devices and systems is another distinction. OPC UA is more interoperable than OPC DA because it is based on a standard set of communication protocols and data models. OPC DA, on the other hand, is based on Microsoft DCOM technology, which can make it more challenging to connect to non-Microsoft-based devices and systems.
OPC DA is utilized frequently in manufacturing and process control systems, as well as building automation and smart grid applications. It is also utilized in industrial automation for real-time monitoring and control of equipment. In addition to being used in these applications, OPC UA is also being adopted in other industries, including healthcare, energy, and transportation.
OPC UA and OPC DA are industrial automation and control system-compatible communication protocols. OPC UA is a more advanced protocol that offers more functionality, flexibility, and scalability than OPC DA. OPC DA is a simple and easy-to-use protocol, and OPC UA is more secure and compatible than OPC DA. The choice will depend on the application’s specific requirements and the organization’s requirements.
There are significant differences between the OPC UA and DA protocols:
OPC UA is a more recent protocol designed to be more extensible and flexible than OPC DA. It can handle various data types and communication patterns and applies to multiple industries and applications.
OPC UA is a platform-independent, open standard, whereas OPC DA is only compatible with Microsoft Windows. This means that OPC UA can be implemented on multiple platforms, whereas OPC DA is restricted to Windows.
OPC UA is intended to be more secure than OPC DA, with encryption and authentication features built into the protocol.
OPC UA is designed to be scalable and capable of handling large data volumes, whereas OPC DA is more limited.
OPC UA is generally regarded as a more robust and versatile protocol than OPC DA, and it is suitable for a broader range of applications. Despite this, OPC DA is still widely used across many industries and may be an appropriate option for specific applications.
