OPC Unified Architecture Facilitates the Exchange of Information in the IoT


The Internet of Things (IoT) and Industry 4.0 needs no introduction, everybody has heard of them, and everybody understands the buzz and the opportunities ahead. But how are you prepared to benefit from this next technological leap while maximizing your opportunity with minimal risk and cost?


Since the 1990’s, technology development has generally focused on the PC platform. During the past few years, focus has been on mobile platforms. Today’s focus is two-fold: small scale devices and large-scale cloud infrastructures, and getting them and everything in-between to work seamlessly together.


Nathan Pocock,
Director of Technology and Compliance at the OPC Foundation


What is driving this change? Data! Successful businesses are maximizing their efficiency to reduce costs. This means that important business decisions need to be made much faster than ever before, with minimum investment, and maximum effect. Is this possible? It’s always been “possible”, it just wasn’t cost effective or easy; now it is!

New products are already available that are intelligent, provide contextual information (discussed in Information Modelling) to enable rapid decision making (human or automated), and scale to the needs of the enterprise. Now it’s your turn!

Introducing OPC Unified Architecture (UA)

The keys to success are adopting open standards such as OPC UA, a platform-independent technology where interoperability is assured.


OPC Unified Architecture (OPC UA) is an industrial M2M communication protocol for interoperability developed by the OPC Foundation.

Initially targeting the Industrial Automation industry, OPC technology emerged in the mid 90’s and was based on Microsoft technologies, but was revamped in the early 2000’s to be a future-facing and platform-independent technology. OPC Unified Architecture harmonizes many existing and widely successful OPC standards (Data Access, Historical Data, Alarms & Conditions, Programs, Security, and more) into one cohesive standard.

OPC products available in the marketplace easily exceed 10,000; the exact number is unknown, and the number of installations is estimated to be in the tens of millions. OPC is used in commercial products and in countless internal-only systems. There is such an abundance of applications such as visualization, data-logging, alert notifications, or other business-intelligence applications, which makes a strong case for adopting OPC UA because your product can integrate with them all, immediately.

OPC technology is platform independent and is already implemented on Windows, Linux/*nix, Apple, Android, and in Embedded controllers such as PLCs, Raspberry PI, and a multitude of other very small-scale circuitry. 

What’s happening now? The number of PC-based applications is massive, but we are also seeing OPC enabled at the controller level, from the DCS, PLC, down to the microchip. Companies such as Beckhoff, GE, Honeywell, Rockwell, Siemens, and others, all have OPC UA enabled hardware.

OPC has spread beyond Industrial Automation that it has served so well for the last 2 decades, and is now deeply rooted in Oil & Gas, Building Automation, and Energy, with more industry horizontals and verticals following.

What Does OPC Do

Why would you choose OPC technology to share data? Because that is what it was designed to do! 

There are 5 core features of OPC: Browsing: the ability to locate OPC systems on a network and to connect to them, and to visually browse the availability of data using a file/folder methodology; Reading: data-points or objects etc.; Writing: to one or more data-points, or entire objects; Subscriptions: receiving update notifications for when data/information changes; and Eventing: to provide meaningful alert notifications. These capabilities provide the entire infrastructure necessary for OPC products to share data/information of any kind, with one another.

OPC technology has three key standards of which the majority of products implement: Data Access, for real-time data sharing; Historical Data/Events, for analytics and reporting of data and/or events stored in a database/historian; Alarms & Conditions, for alarm events that notify when alarm-triggers are hit, such as a temperature reaching a Low or High set-point, etc. Each of these Profiles serves a purpose; you can simply pick and choose the feature/functionality you need within your product(s).


New Era Technologies

OPC is successful because of its plug-n-play design. An OPC Client interacts with an OPC Server. The OPC Foundation Compliance Working Group provides members with Compliance Test Tools (CTTs) for automated compliance testing, test-case specifications, and interoperability workshops for face-to-face testing between different vendors and their products. The OPC Certification Test Lab conducts vigorous testing to validate a product is interoperable, compliant, robust, and efficient with resources. End-users are increasingly demanding Certified products because it reduces their risk, and increases the overall reliability of their infrastructure. 


MTBH? Mean Time Between Hack… will that become a new KPI? Let’s hope not. Power grids, refineries, utilities, and others, have been brought to their knees from hackers. How do you prevent your product from being the cause of such a disaster?

OPC UA provides a significant multi-layer security model featuring end-to-end encryption and signing: preventing eavesdropping and message alteration; sequencing: to detect and request lost messages and to prevent message replay; auditing: to provide detailed activity logs; user authentication: for allocation of user permissions; application authentication: to lock down which systems to communicate with; redundancy: for failover support in the case of lost communications. 

Don’t invent your own security model. Simply adopt OPC UA and inherit the security which was peer-reviewed by industrial cyber-security experts and government agencies, and leverages internationally approved best practices and technologies.

Information Modelling

Data is good, but is not too useful by itself. Data needs context, and this will become even more important as data/information flows freely from system to system as the IoT and Industry 4.0 fully deploy.

Information can be defined as structured data, or “objects”. OPC UA provides a rich information model empowering you to define your own object types, data types, and modelling rules. Once you define your type(s) you can simply create “instances” of them and assure that your data model is always used correctly. This is the core interest of many collaborations with organizations such as BACnet, MDIS, and PLCopen, etc. who are able to define their own object types to represent machines, a part, a building, or a process etc.

Existing OPC applications can readily consume this “information” as individual data-points, which is OK for activities such as data-logging, visualization, or alert notifications etc. However, smart applications will understand the bigger-picture of what this information means and will be able to make more contextual business decisions at higher layers within the enterprise.

An Abundance of ‘Getting Started’ Materials

The OPC Foundation provides a wealth of information to help you get started, from Specifications to sample code, and a product catalogue showing OPC Certified commercial toolkits and systems etc. Getting started may be simpler than you think.

Sample applications are available for download from the OPC Foundation website and are intended to demonstrate and educate the use of the technology. Several OPC Foundation member companies also offer free applications.

OPC Foundation members can download and use the Compliance Test Tools during product development in accordance with Agile/Scrum development methodologies to increase quality and reduce development and QA costs.

The Future

OPC UA is poised to become the de facto standard for securely and reliably moving information from the smallest of devices, up to the largest enterprise or cloud-based systems. OPC UA is leading the way to being a key enabler of the IoT and Industry 4.0 and we are excited to be a part of it!