Interview with Stefan Hoppe | OPC Foundation

Key drivers behind the progression of OPC UA technology are its global adoption as the open standard of choice for secure production-system interoperability across OT and IT networks, leveraging standardised data exchange. To this end, there are now more than 850 registered OPC Foundation members supporting a large, rapidly growing eco-system of end-users, standards bodies, and vendors.

OPC UA also uses a standardised method of defining, discovering, and using Information Models and services associated with the production systems. As a transport-agnostic, IEC standard, it is also supporting two different communication patterns and has the backing of a strong quality assurance program.

Stefan Hoppe, President of the OPC Foundation, has made no secret of his personal delight that OPC UA has emerged as he described in a recent statement as “the one solution harmonised for process and factory automation, scaling from field to cloud – and back”. With the endorsement by the likes of Amazon Web Services, Google Cloud, IBM, Microsoft, SAP and Siemens, it is now the vision of the OPC Foundation to establish OPC UA as THE open standard of choice for data interoperability throughout the world of automation, in his words, “started and flourished with controllers and visualisation systems” that has now reached IT & the cloud, something that will inevitably lead to a further growth of an open eco-system, based on OPC UA. Here, he expands on that vision in an exclusive interview with ACHEMA Inspire Magazine.

ACHEMA Inspire: On a general note, we now have a market dominated by closed source, proprietary solutions. Just how important is it we move away from that?

• __Stefan Hoppe: Be careful, please do not demonise proprietary solutions and closed source – they are all part of the competition and the race for the best offer for special solutions – and competition is first of all good! Others call, for example, different fieldbus systems a fieldbus war – I do not. Most of us have cars and all of them have four wheels, but we love the different models for different needs; whether a family car or a sporty convertible. But all of them have agreed on certain standards, such as for the wheels so that the customer can have the free choice of tyres.

  The standards that we have within automation are like standards for code implementation, such as IEC1131-3 or the OPC UA as the communication interface standard which describes the capabilities for devices, machines but also software services and is also able to exchange standardised information within integrated security.
  But when it comes to security, “open source” is particularly important. This creates the necessary trust through transparency – who would believe a black box and the promise “it is secure without a back channel?”. The OPC Foundation therefore offers an OPC UA sample code as open source, supported by well-known companies and used in their products. But the market also offers commercial solutions from toolkit manufacturers that deliver industrial quality.

ACHEMA Inspire: Your current project involves a collaboration with CESMII. It has been described as a “natural fit”. Apart from the fact you both bring a great deal in terms of expertise, can you explain why in particular?

• __Stefan Hoppe: First, a general statement on co-operation: I increasingly see a “conflict of information models”. Many organisations believe they are the navel of the world and can set international standards alone. I don’t believe that (not even for OPCF), because most products in the field are “hybrid products” supporting different standards on many different levels; for example, within the factory a deterministic protocol down to the field level and OPC UA for horizontal and vertical connectivity.
  So we all need to work together to ensure that these standards fit together. OPCF has had significant success in this because we are a non-profit organisation, which is owned by no-one. In fact, everything is open (open source, open post-release specifications, and open certification, even for non-paying members). In fact, we feel like the “United Nations of Automation” in the best sense of that, where everyone, whoever they are, has only one vote.

  The co-operation with CESMII is about creating an open library of information models that is freely accessible. People can upload new models or search for specific information models and download them. All this serves to create a “world library of information models” and thus helps to speed up engineering processes: One orders a product, such as the pump with the International Standard “OPC UA plus support pump modelling”, and before the pump is physically delivered to the site, the IT world can already start engineering: load the pump information model from the cloud library and implement the software in dashboards, time databases etc.

ACHEMA Inspire: On a wider level, you’ve been keen to stress this is not about the protocol but the data model, or “payload”. Can you elaborate?

• __Stefan Hoppe: Protocols are becoming less and less important – it is always about the secure exchange of standardised information. No protocol in the world covers all application scenarios: Fieldbus protocols do not scale to the cloud and MQTT as a cloud standard does not scale to the field level and is also not sufficient from its properties: MQTT is “payload agnostic” – there is no International Standard which describes the payload in a standardised way. Therefore, OPC UA is more than just a protocol: It first enables data to be describes and then exchanged with integrated security via various protocols integrated in OPC UA – via TCP, UDP, MQTT, etc. And yes: OPC UA as IEC62541 defined a mapping for UDP and MQTT in Feb. 2018. We recently published a PR including major cloud suppliers such as Google Cloud, IBM Cloud, Microsoft Azure, Siemens MindSphere and SAP: All of them support OPC UA (over MQTT) as edge-to-cloud communication! This support is either existing already or it’s on the roadmap.

ACHEMA Inspire: In conceptual terms, OPC UA Cloud Library is clearly a project with infinite possibilities. Is there a current vision – or do you see this evolving?

• __Stefan Hoppe: The Cloud Library is a great co-operative effort between the OPC Foundation and CESMII with great support from well-known IT companies like Microsoft. The Cloud Library is online – you register and gain access via uacloudlibrary.opcfoundation.org. There are already 67 information models available, making it the world’s largest library for interoperable information models (whose instances can be exchanges with integrated OPC UA security).

ACHEMA Inspire: And, if assuming the latter, how infinite are the possibilities?

• __Stefan Hoppe: Infinite. I would assume increasingly automatic code generation for the near future. Artificial Intelligence applications will have this as a basis.

ACHEMA Inspire: I see that none of this precludes the integration of existing assets like information models requiring translators. How important is that?

• __Stefan Hoppe: We have to take the world as it is. There are already information models that describe a robot very technically. This high level of detail is important for the construction but not in all details for the business layers and the job transmission. Here, there are other standards which naturally have an intersection with robots (and other operating equipment).
  So first of all, we must look to the future with open eyes to learn from others and their core competencies- The “consistence one world model” will not exist. However, it is important not to “start over and over again” with modelling. A business process should not define robotic details – others can do that better and have already done it.

  In short, avoiding any duplicate standardisations but referencing in existing models is the key. OPC UA modelling provides these possibilities to reference, for example. IEC Common Dictionaries or commercial solutions such as eClass.