The implementation of the 4th Industrial Revolution is inextricably linked to the coupling of industrial production to the internet and the Cloud. Connecting to the internet boosts the functionality and performance of an industrial plant and machinery – thereby permanently adjusting and improving seamless integration and in the form of digital, value-added networks. Edge devices, i.e. intelligent network components, play a key role here.
Edge devices, which are used directly in the production module – in the plant and machine – provide access to the network of a company or service provider. Edge devices, for example, enable life cycle services such as predictive maintenance, performance management, asset management or spare part management. But they also generate process optimisation through Cloud-based services. The open interfaces of the edge devices employed and extensive integration standardisation are important factors here. In this way, these intelligent systems can be used uniformly by different software systems on the one hand and, while on the other hand, they can also be uniformly integrated into the manufacturing environment. The SmartFactoryKL has generated a concept here and has already demonstrated the first implementation steps at HM 2018. HARTING is also active in the technology initiative SmartFactory KL where it is collaborating with Andreas Huhmann (Strategy Consultant Connectivity & Networks at Harting) as a member of the executive board.
Universally deploy IT Edge devices
Certainly, IT edge devices are all-rounders, since they can be used universally for all services. But there is one exception: automation. On the face of it, this appears to be a contradiction since the 4th Industrial Revolution is often seen as IT assuming all functions in the industrial sector. TSN (Time Sensitive Networks) is a decisive step in this. Now, the Ethernet network can be universally integrated into hard real-time areas. Why shouldn’t the IT edge device be used universally, including for automation? Or, vice versa: Why shouldn’t the PLC also be used universally as an IT edge device?
If one analyses the requirements for a controller and an IT edge device, there are clear differences. The programming of the PLC is adapted to the machine, strongly function-oriented, and uses well-established hardware and software that has already proven itself within the application. The basic function of a machine or of a machine module – for example, a module of the Smart Factory demonstrator – only changes if there are significant changes in the production process. Of course, parameters of the actual sequence can be accessed in order to enable flexible production within the scope of a mass customisation. However, these changes do not affect the modules to such an extent as to require a new commissioning in each and every instance. As a rule, the basic control structure with the deployed control system remains unchanged over many years, something which is necessary not least in light of safety aspects. It is absolutely atypical for a completely new controller/PLC to be installed during the life cycle to increase performance. This is usually only customary after several years, in the course of refurbishment. Refurbishing refers to the quality-assured overhaul and repair of products for the purpose of reuse and re-marketing.
Communication via OPC UA
By contrast, the installation of an IT edge device usually constitutes an expandable platform which is constantly adapted and built out during the life cycle of a machine via the use of additional services. Software updates in short intervals are also common here. However, no new commissioning of the machine takes place, since e.g. safety-relevant aspects are not affected. The software used also meets the necessary standards in the IT environment. OPC UA constitutes an intersection in communication with industrial devices, even if signs are already on the horizon that this communication standard is not the only one that will be used by IT in the industrial environment. IoT standards such as MQTT are also finding inroads here. Consequently, the IT edge device turns out to be a device that is completely built and operated according to IT paradigms. Most of all, it is not rigid and unchanged in the life cycle of a machine or plant. It will continuously evolve with lifecycles far below those of automation devices. This is necessary to keep pace with IT. Conversely, this means that even a PLC will be replaced in a machine at the latest after five years in order to be up to date with the latest IT standards.
The decoupling of IT edge devices and automation device provides further advantages in plant operation. For example, since another jurisdiction exists within companies as well, the devices can be accessed independently.
Suitable interfaces including semantic description necessary
But one thing is also evident – and this has been shown very clearly in the SmartFactoryKL: besides the hardware and software decoupling, a communication connection still remains. The different devices access the same sensors. And if the production process is to be optimised by new services, access to the automation devices is absolutely essential. This requires suitable interfaces, including a semantic description of the devices. Creating these is the urgent task of the future, because in most of today's applications the automation device and the edge device operate completely separately, mostly with their own, dedicated sensors.
This is not optimal either, as both devices have their justification. But their sensible use is not only based on co-existence – their cooperation is crucial. Otherwise, it comes down to a fight that only an edge device with integrated automation control – meaning an all-rounder – can win. But those jacks of all trades have proven to be lame ducks more often than not. Thus the preference for reliance on fast edge devices, which provide the requisite ability for the system or machine to learn over its entire life cycle.
Time-Sensitive Networking (TSN) describes a set of standards used by the Time-Sensitive Networking Task Group  (IEEE 802.1). The TSN Task Group was born from the renamed Audio/Video Bridging Task Group that existed until November 2012 and continues their work. The renaming resulted from the extension of the working sphere of the standardisation group. Standardisation standards define mechanisms for transmitting data over Ethernet networks. The majority of the projects define extensions of the bridging standard IEEE 802.1Q. These extensions mainly address the transmission with very low transmission latency and high availability. Possible application areas are convergent networks with real-time audio/video streams and in particular real-time control streams which are used for control e.g. in automobiles or industrial plants.
An edge device is a network component that is located at the edge of the network and provides access to a core network of a company or service provider. Edge devices are increasingly equipped with intelligence and support various services such as quality of service (QoS) or multi-service functions for different data traffic. In the Internet of Things, edge devices transmit data packets between the various network structures and can use their processors to process sensor and actuator data from smart cities, smart homes, smart grids or automotive technology directly at the application at the edge of the network using edge computing or edge analytics and thus reduce the enormous amount of data of the IoT components. The control, administration and processing of the resulting data becomes much more efficient. At the same time, traffic and network load to the Cloud are reduced.
The SmartFactory KL e.V. (SmartFactoryKL) technology initiative is a non-profit association founded in 2005 that, together with partners from research and industry, implements research and development projects dealing with the gamut of topics surrounding Industry 4.0. The work extends from the development and definition of the Industry 4.0 Vision to its achievement.
Message Queuing Telemetry Transport (MQTT) is an open machine-to-machine (M2M) messaging protocol that enables the transmission of telemetry data between devices in the form of messages, despite large delays or limited networks. Associated devices range from sensors and actuators, mobile phones, embedded systems in vehicles or laptops to fully developed computers. The MQTT specification distinguishes between TCP/IP-based and non-TCP/IP networks