Network Infrastructure / IIoT / Industrial Automation / Digitalization / Big Data Analytics

Move it: OPC classic > OPC UA migration

In this installment of Automation Zone, Arun Ananthampalayam examines how to ensure a seamless transition to the OPC Unified Architecture.

By Arun Ananthampalayam, Honeywell Process Solutions

The OPC Unified Architecture (OPC UA) increases productivity, enhances quality, and lowers costs by providing not only more industrial data but also the right kind of information to critical systems that need it. Organizations deploying this modern standard will be able to better leverage plant-floor-to-enterprise communications as a vehicle to participate in industrial internet of things (IIoT) applications.

OPC UA is the key to moving information vertically through the enterprise of multivendor systems as well as providing interoperability among devices on different industrial networks.

This article describes the key features of the OPC UA versus the legacy OPC Classic standard and outlines the motivation for upgrading to OPC UA based on a managed, secure, and seamless migration path.

Progress of the OPC standard

The OPC standard, first issued by the OPC Foundation in 1996, allows for secure and reliable exchange of data across manufacturing and other enterprises. Countless OPC Classic-based systems are in use around the globe, ensuring the safe and reliable exchange of data among industrial software components.

With OPC UA, the next-generation OPC technology, the vision of “global” interoperability will become a reality. The standard was developed to break down communication barriers that have been limited by dependence on Microsoft’s underlying DCOM technology. It is a platform-independent, scalable, service-oriented architecture (SOA) that integrates all of the functionality of the original OPC specifications into a single flexible framework.

Those who deploy OPC UA will be able to better leverage plant-floor-to-enterprise communications. This technology supports multivendor, multiplatform interoperability for moving data and information from the embedded world to the enterprise.

Benefits of the latest technology

By adopting OPC UA, automation vendors get the best in open data connectivity for today and in the future. OPC UA offers and expands the standard functionality of OPC Classic, and in doing so, it resolves the difficulties associated with security, platform dependence, and DCOM problems.

There are several specific reasons to migrate from OPC Classic to OPC UA:

  • By natively enabling OPC UA in devices and applications, users no longer have to rely on clumsy tools for protocol translation and information modeling. This solution reduces operating and capital expenses by eliminating middleware on the shop floor as well as the need for hardware to install servers and clients.
  • Unlike OPC Classic, OPC UA is inherently cyber-secure and thus eliminates the need to layer multiple security gateways or software.
  • OPC UA offers a rich set of functionality, including the ability to provide contextualized data that is valuable for advanced analytics to enable improved insights and better decision-making.

It is clear that switching to OPC UA is worthwhile, and for those developing tomorrow’s intelligent devices, it’s a necessity. OPC Classic simply cannot address the requirements of Industrie 4.0 or IIoT initiatives.

Proven migration strategy

A growing number of OPC Classic users are starting to ask themselves how and when they should begin the implementation OPC UA. In many cases, the migration path to the new standard isn’t clear. There’s often a lack of understanding of how OPC UA works, and even after the decision to transition has been made, there may be confusion about the best approach. Many users are also reluctant to “rip and replace” existing investments. Automation assets are typically supplied by different OEMs that maintain proprietary protocols and are concerned with protecting their installed base. All too frequently, the customer has no choice but to purchase new products to access new OPC UA features.

The aforementioned obstacles can make technology migration costly and difficult to manage. And although it’s safe to assume that OPC UA will one day replace OPC Classic, an immediate switch to OPC UA isn’t necessarily required for every business. With the right tools and careful planning, migration becomes accessible and doable.

Leading automation suppliers regard the OPC UA standard as a solution for meeting the need for enhanced connectivity in all plant things – from device to cloud – in a cyber-secure environment. This includes advancing cloud connectivity, predictive maintenance, asset health/performance monitoring, anomaly detection, and condition-based monitoring.

Industrial organizations need to be mindful of the following best practices intended to enable a smooth transition from OPC Classic to OPC UA:

Step 1: Be sure that all legacy proprietary protocols are future-ready.

Complete migration refers to replacing OPC Classic via a comprehensive switch to OPC UA. To that end, however, users need to keep third-party data always accessible using an open standard that enables reliable communication between human-machine interfaces (HMIs), applications, and devices. By utilizing suitable OPC servers that support open connectivity to communicate with multiple units, protocols, and APIs regardless of the vendor, they can achieve secure connectivity with all established management systems and applications via OPC Classic.

Step 2: Start with partial migration.

OPC UA has been designed to remain adaptable for the future and to support legacy implementations. In the intermediate phase, it will be possible to use DCOM-based OPC products together with UA products.

Users can still run a variety of products from their current favorite manufacturers. This allows for a soft migration in which they retain OPC Classic data sources and integrate OPC UA in future devices according to their needs and capabilities. Devices using OPC Classic cannot communicate with OPC UA on their own. For these instances, it is wise to use a wrapper to provide a partial solution for handling communication between existing OPC Classic servers and OPC UA clients.

Users are finding that a new breed of software tool provides a secure method of migrating OPC Classic data sources to OPC UA. It lets OPC UA-enabled client applications communicate with OPC Classic servers and clients as well as OPC UA servers. The reverse is also true. Such tools are designed to enable seamless OPC data transfer through multiple mediums across locations, address problems with using OPC Classic components based on DCOM, and eliminate permission issues.

Step 3: Enable OPC UA connectivity across products and platforms.

The continued demand for open and secure connectivity between devices (machine-to-machine) and edge-to-cloud solutions makes it necessary to have a single, fully scalable toolkit to allow users to easily interconnect industrial software systems regardless of platform, operating system, or size.

Today, automation OEMs can use an advanced software development kit that provides high-performance capabilities (e.g., multi-threaded, load balancing, small memory footprint, etc.) and makes it easy to embed an OPC UA server into a chip, device, and/or application. With this solution, developers can natively enable OPC UA servers and clients in controllers as well as in devices, sensors, and applications.

OPC UA is a crucial enabler of major advancements such as the IIoT, Industrie 4.0, and cloud computing. Many industrial firms are seeking to take advantage of this innovative technology but are wondering where to start. Users need an effective strategy for migrating from OPC Classic to OPC UA – one that employs logical steps to minimize the time, cost, and risk associated with this process. The goal is to make it easy to assess an organization’s migration requirements and then implement a seamless, end-to-end solution.