In practice, it is common for a heterogeneous system landscape to be changed or expanded. If data transfer takes place with the help of middleware, the core of the transfer remains the same. That is entirely independent of whether a new system component is added to the existing landscape or replaced. That means that the current system landscape can be changed or expanded at will, both in OT and IT, creating the opportunity for scaling.
Middleware makes it possible to expand or change a system landscape at will – the data transfer remains at its core.
For example, it is possible to switch from one control system to another without further ado. In the same way, it is also possible to integrate a machine into another machine park without any problems.
Middleware vs. API
An API (Application Programming Interface) is a programming interface offering, similar to a middleware, the possibility to network applications and let them communicate together. As the name implies, the use of an API requires programming. Through an API, programmers can connect systems using commands, functions, protocols, and objects.
Thus, the API is also a way to connect system components to each other. In contrast to an API, a middleware relies on many interfaces to provide more flexibility in the ability to connect systems.
Middleware vs. protocols
Protocols are a central element of communication between systems and applications. They define the way in which information is exchanged. These include, for example, rules, formats, parameters and properties of data that ensure complete, error-free and efficient data transfer. Examples of IT protocols are the HTTP, TCP or IP protocol.
As with API, each protocol represents a way of regulating communication between two system components. Middleware, on the other hand, bundles many protocols and offers the advantage of flexibility in linking individual system components.
When choosing the appropriate middleware, there are several criteria that should be checked. In addition to the prerequisite of independence from protocols, operating systems, languages, and platforms, as well as background operation, there are several further criteria that should be considered in the selection process:
- Security: security is a key consideration where a lot of data is collected and transferred. Sensitive information such as customer or production data needs protection against access by unauthorized persons. Middleware must always meet the highest security standards and guarantee security.
- Scalability: A middleware should be able to be implemented in a scalable manner. Adding new system components at the IT and OT level should be possible with a middleware without much effort.
Connectivity diversity: For maximum flexibility and to map the heterogeneous system landscape in the best viable way, middleware should provide an API and offer the option of integrating different protocols.
- Continuous further development: The use of middleware should support a company’s long-term digitization strategy. It is particularly important that the software is constantly optimized and further developed, and that regular updates and support are offered.
- Programming effort: If a company has only limited resources for programming interfaces, or none, this is an important criterion when selecting the right middleware. There is middleware software, such as OPC Router, which enables the connection of individual system components on a graphical user interface and for which programming knowledge is not a prerequisite for use.
Its universal functionality allows middleware to be use across industries and use cases and thus supports digital transformation. In the following, we explain two practical examples from industry in which processes and data transfers are controllable with the help of middleware.
Providing the controller (PLC) with data and decisions
In automation, controllers coordinate complex machine sequences and production processes. During a production chain, many decisions depend on data from other systems. An example is customer order data, which varies from customer to customer and is stored in a database or an ERP system. It is possible by using middleware to automate the transfer of this data to the PLC. The middleware captures the customer order data and sends it to the PLC to start production. Based on defined communication standards, for example, OPC UA, a middleware can communicate with the machine. This communication eliminates the need for manual entry of order data directly in the OT and ensures fast and efficient production.
Receiving alarms and thus keeping an eye on production
Machine data acquisition and the evaluation of this data are essential components for efficient production. With the help of middleware, data from a control system can be linked to IT. In industry, a decisive advantage here is alarming. Middleware receives data from the machine, analyzes it in real-time and can send notifications based on this data. For example, the middleware can be used to send an alert to the responsible employee when a production job has been completed. The employee can then transfer the next order from the system to the machine and start production for the next product. Limit values on the machine can also be transferred to the IT system via alarms. For example, if temperatures in a machine are too high, employees can be informed in real-time and can then react and initiate countermeasures. In this way, production stops can be prevented, and downtime avoided.