The implementation of Industry 4.0 projects has many hurdles. However, one problem has been clearly solved: There is a way to establish system connectivity for every initial and target situation. It is now easy to record data in a system or to trigger it from a controller. Here is an orientation in a confusing field of factory automation.
Just a few years ago, it was only possible with great effort to read even simple signals, such as the units produced, from a system. Systems were closed systems and external communication was often not intended or was so prohibitively expensive that the operator refrained from doing so. However, with the advent of Industry 4.0 and the recognition that the concept is intensely data-centered, the situation has fundamentally changed.
There are now hardware and software solutions for old and new systems, which cover the entire range of use cases. However, the solution landscape remains unclear, as it is unfortunately impossible to sort connectivity concepts without overlapping. Therefore, this is an attempt at a simplified description of archetypes, in the knowledge that the actual variety of solutions is greater and requires a close look at the initial situation and the desired target state in order to design a long-term, suitable solution.
Four archetypes for plant connectivity
The following table shows four archetypes of connectivity, which are discussed in detail below:
Archetype descriptionSystem age and requirementsPossible use case complexityPlug & play retro fitAddition of, for example, quantity or vibration sensorsRegardless, no requirementsLow to mediumIntegrated retro fitAddition of an industrial PC or a connector box, PLC must be availableMedium to highSoftware layerUse of a “data layer” via Industrial Service Busegal, PLC must be availableMedium to very highControl NativeAvailability a new generation of controllers with OPC UA or REST APINOnly new systemsLow to very hightable: Four archetypes of plant connectivity
Plug-and-play retro fit — the quick solution
We call the lightest form of connectivity “plug & play retro fit.” This involves adding additional sensors to the system, which operate autonomously without further system integration. For example, quantities can be counted directly or derived from vibrations — the vibration itself can also be a relevant signal. These sensors are available with or without a wired power supply and usually send their data — directly or via a mesh architecture, for example — to the cloud for further processing. Use cases with low to medium complexity can therefore be implemented. One example of a simple case is identifying whether a plant is being operated or not. This can be achieved by means of a networked vibration sensor.
However, this type of connectivity is not suitable for all types of systems. While oscillations are easy to count for clear quantities, this technology reaches its limits when producing, for example, meters or continuous plant operation. On the side of advantages, however, this form of integration has its simplicity, the absence of intervention in the system control system and sometimes even the absence of a power supply.
Integrated retro fit — the flexible solution
The next archetype is described as “Integrated Retro Fit.” Windows or Linux computer hardware is connected to the system's PLC via software connectors. The connectors map the data from the PLC to software running on the computer, from where connectivity, e.g. to the cloud, is established. The communication standard depends on the app used. MQTT, for example, is common here. Since there is a direct connection to the system control system, a variety of signals can be read out.
Software layer — the sophisticated solution
Another variant of system connectivity is a software data layer above the control systems, which, depending on the provider, is referred to as an industrial or manufacturing service bus, for example. This is an evolution of what was referred to as “middleware” in the past. In this variant, the PLCs of the systems are connected to the data layer and deliver their information there. Use cases can now be mapped directly to these levels — e.g. real-time connectivity between different systems — or it can be used as a gateway to cloud services. With this infrastructure, demanding and complex use cases can be mapped.
Control Nativ — for new systems
The last variant of connectivity is in turn hardware-based and is referred to as “Control Native.” These are new generations of controllers that have built in connectivity directly, as a native. Examples include OPC-UA or REST API technology, which are implemented in the system.
Hybrids blur order
Understanding plant connectivity is made difficult by the fact that the above archetypes are not always found in their pure form, but that there are a variety of hybrids. For example, an OPC UA controller can be connected to any industrial service bus, or there is the variant that a controller from a specific manufacturer is available with its own data layer.
And even with Retro Fits, it is important to keep the application in mind: Vibrations are not sufficient information for all applications, while not every product can be counted discreetly.
synopsis
What can be said in summary: The options for reading data — even in real time — from systems are manifold. The prices are not prohibitively high, but surprisingly low. Since, as a plant operator, you usually own a heterogeneous plant park in terms of manufacturer, technology and age, you should consider the planned use case before deciding on one of the technologies. After all, this is an infrastructure decision that you don't want to reverse anytime soon.
connectivity to oee.ai
As a manufacturing intelligence platform, oee.ai must be supplied with plant data. Depending on the date, the date of receipt is usually an MQTT message or a REST API call. And these messages or calls can be easily generated by all four connectivity variants. oee.ai is therefore connectivity-agnostic. For discrete, quantity-related use cases, oee.ai even provides the hardware as a package for a proof of value to test the functionalities. We have experience with all connectivity options. Please feel free to talk to us.