Process Industry Facing Upheaval
With Ethernet-APL, IP communication reaches the field level in process automation for the first time – intrinsically safe, robust, and interoperable. This presents new challenges for device manufacturers.
Many process plants worldwide are still based on classic 4-20mA field devices, most of which also use HART communication, or on two-wire fieldbuses. While all of this has proven itself over decades, it is reaching its limits in terms of digitalization, remote access, efficient comissioning and plant availability. Ethernet-APL (Advanced Physical Layer) now offers a technological solution to bridge the gap between modern Ethernet communication and the specific requirements of the process industry. For the first time, seamless communication from the field level to the cloud is possible – an essential prerequisite for the efficient digitalization of process plants and a crucial building block for their autonomous operation.
In comprehensive pilot projects – including those at large chemical plants – Ethernet-APL networks were tested with several hundred devices from various manufacturers under real-world conditions. The results are compelling. The core features of PROFINET – stable communication, high availability, fast configuration, and improved fault diagnostics – are now available for instrumentation in the field of process plants via Ethernet-APL. The behavior during redundancy switching, hot swaps, and topology changes was rigorously tested on current, available products – with very positive feedback from users.
What does this mean for device manufacturers?
Ethernet-APL is not a simple add-on to existing components; it’s a completely new design, from the electronics to the firmware. Developing Ethernet-APL-enabled devices was a technological challenge for the pioneers. Today, solutions and technology providers exist that make life significantly easier for manufacturers.
This will become clear through a few examples:
One of the biggest challenges lies in the miniaturization of electronics, especially for intrinsically safe products. Integrating an Ethernet-APL transceiver, an Ethernet stack, and the power supply into a compact device for Zone 0 is technically demanding. Here, explosion protection requirements must be reconciled with thermal performance and EMC. Ethernet communication has high power requirements due to its high transmission speed. At the same time, the available power is strictly limited for explosion protection through intrinsic safety. Manufacturers must therefore develop devices with maximum energy efficiency. The big number of devices that are already available proofs that this challenge has been solved by a number of suppliers.
Within the framework of the Ethernet-APL project, corresponding testing strategies and systems were developed to ensure transmission quality and EMC compliance. This helps manufacturers qualify their products in-house during the development phase, thereby reducing effort and development time.
Almost all field devices available today for Ethernet-APL communicate via PROFINET – a proven technology. However, there was a not-entirely-surprising challenge on the system side, which has since been resolved: while I/O modules in control systems consolidate measurement signals from multiple instruments under a single PROFINET address – e.g. in the case of the remote I/O, this can be 184 analog process values – each field device receives and occupies its own address. This high number of nodes posed a challenge in some implementations. Device and system suppliers addressed these issues, which inevitably accompany the growth of a new technology, and resolved them through close collaboration.
The PROFINET specification perfectly matches the requirements of Ethernet-APL and those of the process industry. The devices available on the market function well. This is demonstrated not only by the scalability tests at Endress+Hauser , which have now been successfully completed with four control systems, but also by the first large-scale plants, including one with tens of thousands of field devices, which are currently in start up .
The stable, internationally recognized specifications for communication via PROFINET and for the Advanced Physical Layer mean manageable risk for device manufacturers during implementation and the assurance of being able to offer a market-ready and, above all, interoperable product.
Good Prospects – Ethernet-APL will Become an Industry Standard
Infrastructure and equipment manufacturers released their first generation of devices with Ethernet-APL some time ago, allowing planners, operators, and system integrators to gain valuable experience in numerous pilot projects and early adopter installations. These manufacturers are convinced of the potential of Ethernet-APL and are continuing to invest. Many new products with new features will therefore soon be available. Ethernet-APL is establishing itself as a standard in the process industry.
Ethernet-APL fundamentally changes communication by providing seamless connectivity all the way to the field level, marking the transition to the digital age of process automation. With robust two-wire technology, high data rates, explosion protection, and Ethernet connectivity right up to the field device, applications previously unheard of become a reality in the field. This is a transformation of this magnitude rarely seen in the process industry – an opportunity every manufacturer should seize.
Michael Kessler