We cannot create the future of manufacturing using the resources of Industry 4.0 in one fell swoop, by simply replacing existing equipment. Breaking the process down into small steps is frequently the way to achieve better and more sustainable outcomes for digital transformation.
The goal of Industry 4.0 is to create agile production processes that can respond dynamically to changing requirements. This involves continuously collecting large quantities of process data from individual machines and within networks of these machines. This process data is then forwarded for evaluation to system units at various levels of operating technology (OT) and information and communication technology (ICT).
Ever-increasing quantities of data are collected and evaluated in order to digitalise all of the business and production processes. From adding industrial value right through to Industry 4.0, digital transformation enables companies to design more robust systems and equipment that they can maintain more efficiently — and also to develop completely new business models. The data is the basis for agile responses, ideally as a result of autonomous and automated decisions made by the system itself.
This requires comprehensive networking of all machines and systems, as well as additional sensors and actuators between these machines and systems, ideally across all company locations. Although this doesn’t necessarily involve the data leaving that company’s possession, the underlying methods that are used mean this is referred to as the Industrial Internet of Things or IIoT.
A sobering choice of location
The fourth industrial revolution, Industry 4.0, was announced at Hannover Messe 2011 — and it’s hard to believe that a decade has already passed since then. According to a survey [1] conducted in mid-2019 by IT market intelligence company IDC on the degree of implementation of the IoT in the industrial sector, however, self-optimising systems are still the exception rather than the rule. System breakdowns between the individual components of production systems continue to be frequent hindrances and the IIoT is only rarely used as an information hub.
Despite that, the study indicated that 75% of industrial companies in Germany intends to implement IIoT projects in the near future. When the survey was conducted, the majority of decision-makers in the production industry in particular, but also in logistics and in the supply and disposal sector had already identified the IIoT as an enabler of digital transformation. Even so, their machines, control hardware and software had often been added and expanded organically over many decades. Replacing full systems or even just individual machines is out of the question for most companies when it comes to the consistent digitalisation of production.
Retrofitting as an alternative – transformation into Industry 4.0
The good news is that retrofitting is an alternative way of gradually converting machines and systems into cyber-physical components and integrating them into the IIoT. Provided the company in question has the relevant IT and overall control systems, the machines and systems can be equipped with up-to-date and consistent operating concepts that increase their level of automation. The cables and networking of existing systems (referred to as brownfield, in contrast to new systems in the proverbial greenbelt) and the additional sensors that are required present complex challenges for companies that want to automate their systems.
According to Thomas Kruse, Product Manager for Network Technology, Smart Home and Security at electronics distributor reichelt elektronik: “There is no easy way to overcome these challenges because each individual case involves responding to different requirements and specific circumstances. As a result, rejuvenating industrial machines and ‘computerising’ them to make them fit for the IIoT is a logical, future-oriented task for automation companies”.
Creating modularity and independence
The trick is to be open-minded about utilising existing opportunities at the various points across the entire network in order to get the best results from adapting them to the requirements that apply at that point. And also to develop an entire system that was inevitably designed to be heterogeneous into a flexible modular design made up of autonomous units. Having a good knowledge of the many different technical options for networking existing and retrofitted sensors and actuators in the machines, along with their PLC systems and ancillary/superordinate systems is therefore an advantage.
Choosing agnostic technology and products is a way of avoiding overdependence on the preferred standards of individual hardware manufacturers and of ensuring a high degree of efficiency for operations and maintenance. The primary focus here is on connectivity at the various levels of data technology.
Data transport media
When it comes to choosing the actual medium for holding the data, there is a huge choice. Kruse illustrates the differences between the available choices: “Inside the machine itself, you’re probably more likely to opt for industrial copper wires with M12 fittings, for example, and only use optical fibres in applications that are susceptible to outages. When it comes to external communication, the level of difficulty and costs frequently involved in laying cables in existing production facilities mean that WIFI and other wireless transmission networks are becoming increasingly popular”.
Not least the impending 5G wireless standard, which is unquestionably suitable for transmitting data in the IIoT and which is being heavily advertised. Countless manufacturers are launching devices capable of being used to create the necessary connections, with more appearing all the time. As a result, data transmission will end up significantly further down the list when it comes to calculating plant operations.
An alternative option is transmission networks developed specifically for the IIoT, which allow sensors to bypass the existing control systems and communicate directly with IT. These networks include global wireless network Sigfox and the Long Range Wide Area Network (LoRaWAN). LoRaWAN sensors score with an extremely low energy consumption and an extremely high level of inherent data security, making them ideal for integrating remote and even mobile systems.
Existing equipment — supplement or bypass?
The additional data and signals from retrofitted sensors are useful not only for superordinate systems, but also for local control, regulation and visualisation systems. The best option for connecting to these systems is usually I/O assemblies that are compatible with the existing fieldbus or Industrial Ethernet. Component selection for this will be significantly influenced by whether there is adequate space to fit DIN rails in the existing control cabinet or in any extra ones added as required. If no space is available, then being able to access variants in a higher protection class and with an expanded temperature range, as well as with the option of being powered via low voltage or by being mounted on the machine frame itself will be essential.
Existing machine control systems frequently do not have any free capacity, so manufacturers of IIoT solutions often have to incorporate an additional level of processing. As Kruse explains: “This involves a local computer ‘brain’ handling the preprocessing and conversion of the additional information, communicating with the existing control unit and forwarding the data to external recipients. Industrial designs of the Raspberry Pi microcomputer, which can be flexibly programmed, are increasingly replacing the SPS devices that used to dominate this role.”
One-stop shop – important for Industry 4.0
Whether companies choose to continue using the existing network structure, introduce a wireless network or connect directly to cloud services (or a combination of any or all of these options), switches, routers and protocol converters are key elements in retrofit connectivity. As is the case with all other components, from cable manufacturing through to over-voltage protection, the criteria extend beyond whether these key elements are available in industrial designs. As Kruse explains: “IIOT projects are highly individual and involve using components and devices in minimal quantities right down to individual items. They need a supplier that can provide them with the required hardware that has the appropriate compatibility features and they need it quickly, in small quantities and with long-term replaceability — all from a single source.”
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