Smart protocol: machine tool communication in a connected world

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The OPC UA protocol does not have much visibility in the UK, so what is it, what are its origins and who’s signed up to its use or application? Andrew Allcock went in search of answers

United Grinding Group company Studer is employing the OPC UA protocol to connect its machines to external networks as part of its effort in making equipment for the smart factory, or the Industry 4.0 world of connected devices. Machinery suspects that this protocol is not known to many of its readers; indeed, it wasn’t on our radar, either, but it is the standardised means of secure communication on which Industry 4.0 is set to be built, it appears.

OPC UA started its journey in 2004, succeeding the now-termed classic OPC that dated from 1996. Original OPC took its name from ‘Object linking and embedding for Process Control’ (although Studer uses ‘open platform communication’ for the OPC bit). This allowed HMI (human machine interface)/SCADA (supervisory control and data acquisition) systems to interface with a ‘middle-man’ that would convert generic-OPC read/write requests into device-specific ones and vice-versa. OPC UA (UA=Unified Architecture) doesn’t demand MS Windows as a platform, as did earlier OPC versions, and it also adds XML and web services to existing ones. OPC UA is managed by the OPC Foundation (www.opcua.us).

First OPC UA industry implementations were available in 2008. In 2009, the initial OPC UA software kit arrived. In 2015, the UA specification was made public and in April 2016, code became ‘open source’.

Said the Foundation of the latter: “Open source is a very important strategy to eliminate roadblocks to adoption of the technology. By open sourcing the OPC UA technology, the OPC Foundation is now enabling easy access to the technology by academia and research organisations, as well as many suppliers and end-users that would like to assess the OPC UA technology as part of early adopter and feasibility analysis.” And things have most certainly taken off since 2016.

Indeed, in the same month, at the Hanover Fair, Microsoft stated that it “is working with the OPC Foundation to enable virtually any industrial Internet of Things (IoT) scenario through interoperability between the millions of applications and industrial equipment compliant with the OPC UA standard. Microsoft will further enable its industrial IoT customers to connect a broad range of manufacturing equipment and software that can span decades of investment with extended support of the OPC UA open source software stack”.

That endorsement and adoption was taken as big news by the Foundation. Said Stefan Hoppe, OPC Foundation vice president: “With the adoption by Microsoft to its Windows 10 operating system and Azure cloud, the OPC UA standard passes the critical milestone of general acceptance by the broader IT world.”

Communication protocol bodies signed up to work with OPC Foundation at the Hanover Fair, too, among them CC-Link Partner Association, an international organisation with over 2,600 member companies worldwide that work to promote and develop technologies such as CC-Link IE (Industrial Ethernet) and CC Link (fieldbus) in machine-to-IT activities; and also CAN in Automation e.V, whose users develop CANopen automation technology.

In November last year, German mechanical engineering association VDMA joined the growing throng, saying: “We want to make machine vision fit for Industry 4.0 and for the factory of the future. We are aiming at straightforward integration of machine vision systems into production control and IT systems via OPC UA.”

Prior to these 2016 signings, AutomationML (data exchange standard for engineering data standardised in IEC 62814) got together with the Foundation in November 2013. AutomationML uses a number of open standard formats, including Computer Aided Engineering Exchange (CAEX) according to IEC 62424 to describe plant topology information (e.g. for robots, machines and cells) and COLLADA according to ISO/PAS 17506 to describe geometry and kinematics of manufacturing equipment.

Over in the USA, the MTConnect (www.mtconnect.org) industrial equipment communication interface effort is also a partner, having joined with UPC Foundation on the UA effort in September 2010. MTConnect has been ongoing since 2006, with a first public demonstration at IMTS, Chicago, in 2008, although visibility of MTConnect outside of the USA is low.

So expect to hear plenty more reference to OPC UA from now on.

This article was published in the March 2017 issue of Machinery magazine.