Ethernet-APL: A partnership that benefits the customer

André Fritsch: Users' demands for digital communication right down to the field level is nothing new – there are and have always been a range of approaches to achieving this aim. However, this is exactly where users run into problems. The available solutions are very varied, incompatible with one another, proprietary and, above all, typically not suitable for modern digitalisation concepts. Hence the call for "Ethernet in the field" and Ethernet-APL, the answer to this call.

Ethernet Advanced Physical Layer (APL) technology holds the key to digitalisation right through to the field level. In doing so, Ethernet-APL relies on global, open standards from the IEEE and IEC, as well as 2-wire solutions with 10 Mbit/s and suitability for distances of up to 1000 m, standardised as 10BASE-T1L.

For the specific requirements of the process industry, the Ethernet-APL team used this as a basis to work on additions, such as intrinsically safe connection and supply of field devices. This enables the user to implement the globally distributed Ethernet technology, which is used across all industries, even in their process technology systems.

Thomas Rummel: Ethernet-APL will revolutionise industrial communication in the process industry. It meets the installation and safety requirements of the process industry and, with 10 Mbit/s, offers a good bandwidth that is significantly higher than any technology available up to now. With the support of Ethernet, all Ethernet-based communication protocols on the controller and industrial edge level can be used right through to the field device level. This therefore also enables immediate implementation of open architecture concepts such as NAMUR Open Architecture.  

André Fritsch: That's a tricky question to answer at this point in time. Whenever you work with a new technology, you are bound to encounter new challenges and uncertainties. This means that nobody can currently say for sure how well the products from different manufacturers will function as a whole under extreme conditions. As a result, we will perform extensive tests and conduct joint interoperability tests within the Ethernet-APL team. Softing is at our side as an expert partner in this respect, as well. Both companies are addressing their core markets with the planned products and solutions. For instance, R. STAHL will specifically serve the Zone 1 market, since there is great demand for suitable field installation solutions for Zone 1, in particular, as well as for Ethernet-APL components. With these Zone 1 system solutions and our Remote I/O systems, among other concepts, we have been able to develop outstanding expertise over the past 35 years, from which Ethernet-APL users will now benefit.

Thomas Rummel: Softing has been present on the market with Ethernet gateway solutions for fieldbuses in process automation for decades. These are usually installed in Ex Zone 2. We will also focus on installation in Ex Zone 2 or in non-hazardous areas when it comes to our APL switch products. This means that the range of products we will offer as a result of our collaboration will be an excellent addition.

André Fritsch: I think that both companies will certainly have some interesting developments on show at ACHEMA 2022.

Thomas Rummel: Yes, at ACHEMA 2022 we will present both the APL switches and the commModule APL for easy implementation of APL in field devices.

André Fritsch: The goal that the Ethernet-APL working group set itself is and has always been to make this changeover as simple as possible for our users. With this in mind, for instance, we attached great importance to ensuring that the type A cables that are frequently used for FF H1 and PROFIBUS PA are also suitable for use with Ethernet-APL. Even lower-quality cables, such as those that may be used with classic 4 to 20 mA and HART installations, can still be used, albeit with limitations. To ensure that this is the case, a range of cable categories have been specified; these can be used to upgrade even existing systems without having to change the cabling. Another advantage of Ethernet technology is that completely different systems are able to work together in a single network. For instance, is it possible to construct one system part with Ethernet-APL field devices, while another system part continues to use conventional field devices, bringing them into the joint Ethernet backbone by means of Ethernet-capable Remote I/O systems.

We have already achieved this without Ethernet-APL. Our IS1+ Remote I/O for Zone 1 collects all field device data, including HART, and communicates with the control system via a PROFINET S2 ring, for example.

Thomas Rummel: We have also carefully considered 2-wire fieldbuses. To enable easy implementation and early use of Ethernet-APL, we are planning to integrate functions of our existing products, such as the pnGate, into the APL switches. This makes it possible to convert field devices in systems from PROFIBUS PA to PROFINET in a step-by-step process.