Digital Transformation of Process Plants – An Introduction to Ethernet APL
Published on : Thursday 06-07-2023
Ethernet-APL is based on the absolute world standard in data transmission, says Binoy Kamath.
Everyone is talking about Industry 4.0, the Internet of Things (IoT), Big Data, the Cloud, mobile communications and Internet everywhere. However, the global process industry has largely missed out on the digital revolution so far and there were good reasons. But it's time to rethink, because Ethernet-APL has triggered a whole new era for the Process Industry.
Introduction
Process plants generally have a life cycle of several decades. They are often large plants with a considerable geographical spread. Not only does the communication infrastructure need to bridge large distances. It is also constantly exposed to all kinds of weather conditions and must therefore be designed to be particularly robust. In addition, there are often high electromagnetic influences and/or potentially explosive areas, which place very special demands on all infrastructure components. In addition, in process plants it has also proven to be the best solution to route both the data and the power supply of the individual field devices via one and the same cable.
Plant operators therefore have good reasons to stick with proven technologies that are backed by many years of experience.
At a glance
Ethernet for the field of process automation needs
a. Barrier-free access to data
b. Field device autonomy
c. Engineering, and
d. Communication and power supply on a two-wire line
However, technical development has not stood still in the process area either. As a result, the automation system of a plant often consists of several systems that operate according to different standards and communicate with each other via gateways. Engineering, operation and maintenance of such a heterogeneous environment are correspondingly complex and data communication is associated with numerous restrictions. For example, different data formats repeatedly cause field devices to communicate imperfectly with the system and thus existing information remains unused.
This often historically determined situation also requires numerous time-consuming manual processes in the design, implementation, modification and expansion phase of a process plant. Technical problems can often only be assessed directly on site. The replacement of defective devices requires time-consuming calibration and parameterisation and preventive maintenance is extremely difficult to realise. The implementation of efficient maintenance concepts is hardly conceivable under such conditions.
Data must be available at all times
The process industry considered Big Data as the decisive key to more efficiency and profitability of a plant. This makes it all the more alarming that around 60% of the time currently spent on Big Data analysis does not actually bring any benefit, but is required solely for acquisition, preparation and processing of the data. In today's digital world, however, data should actually be as readily available as electricity from the socket.
The prerequisite for this, however, is that the continuously generated process data of the individual sensors, actuators and measuring devices in the field are seamlessly recorded and made available centrally at one point. Modern field devices provide such data in abundance. Within today's system environments, however, it usually requires very high technical efforts to access them. At times it is often completely impossible.
Ethernet-APL is the key to a new type of flat communication infrastructure in the process area. It stands in contrast to the hierarchically structured system environments of today's plants and allows unhindered access to all process data down to each individual field device. In addition, Ethernet-APL field devices and other infrastructure components allow data access fully independent of the running process and are also able to communicate directly with each other. Process data is therefore available without restriction. Big Data applications can draw on the full potential and no longer fail due insufficient availability of data.
Vendors and users in interaction
The impetus for the development of Ethernet-APL was essentially given by two organisations. The Open Process Automation Forum was focused on completely new system architecture for the process industry. The Namur Open Architecture (NOA), on the other hand, was looking for ways to make process data from the automation system usable for the purposes of plant maintenance and optimisation without affecting the ongoing process flow.
The vision of both initiatives included a solution that would not require any gateways between individual networks or fieldbuses. In addition, the process and status data provided by the individual field devices should be openly accessible at all times. On the one hand, a new generation of field devices should enable the use of different protocols to suit the respective application. On the other hand, it was about transmission paths with high bandwidths that allow fast access to the field devices, thus opening up completely new applications.
The path to Ethernet-APL began in 2011 with a conference of leading suppliers of components and systems for the process industry. It soon became clear that all participants were actually driven by the same vision. The declared goal was an open solution that guaranteed full interoperability and put an end to the complexity and limitations of the existing system environments. It was all about nothing less than a new standard that not only offered unrestricted transparency, but also enabled high transmission rates. In addition, Intrinsic Safety ignition protection for hazardous areas was to be made possible and the proven principle of transmitting both data and the energy for operating the field devices over long distances was to be retained.
A first demonstrator was presented in 2015. With this setup it was proven that Ethernet-APL was indeed capable of transmitting data and electrical energy over 2-wire cables and long distances.
In 2018, the three leading user organisations in the process sector demonstrated that they were fully behind Ethernet-APL. A joint presentation by Profibus International, ODVA and the FieldComm Group presented practical solutions for the first time to demonstrate the capabilities of Ethernet-APL and position the new technology as the future standard in process automation. In addition, migration paths were shown that enabled an easy transition from the current heterogeneous system world to the digital future.
Part of the omnipresent network standard
As the name suggests, Ethernet-APL is based on the absolute world standard in data transmission. Ethernet was introduced as early as 1973 and has since developed into the ubiquitous transmission technology that can be found in the private sector as well as in the administrative areas of organisations worldwide. Today's information technology is unimaginable without Ethernet, and in the form of Industrial Ethernet, the standard has long since found its way into factory automation.
Until now, process plants have been more or less isolated solutions that offer only a few interfaces to the information technology of the company that operates them. This results in numerous restrictions, which are removed by Ethernet-APL, which is based on the worldwide Ethernet standard. The suffix APL stands for Advanced Physical Layer and describes a physical layer for the transmission of data and electrical energy via 2-wire cables and distances of up to 1000 meters.
Ethernet-APL will thus become an integrated component of a uniform and universal communication landscape, making the principles of Industry 4.0 a reality for the process industry as well. After all, Ethernet is just as much behind the Internet of Things as it is behind Big Data, the cloud, ubiquitous mobile communications and the Internet.
New field devices for completely new possibilities
The vision of the organisations driving Ethernet-APL also includes concrete requirements for Ethernet-APL-capable field devices and infrastructure components. The principle is based on self-contained field devices that can be easily integrated into any system environment without a high degree of adaptation effort. Such devices can be automatically integrated by the system controller, whereby the configuration made when the system was commissioned is automatically transferred to the replacement device.
Such devices not only instantiate themselves in the network; but they also can be put into operation and easily replaced, in case of failure without the need for time-consuming manual configuration.
Since Ethernet APL-capable field devices do not require a gateway to communicate with the automation system, there are no longer any restrictions on data transmission. Instead, there is unrestricted access to all process and status data provided by the respective device. These can be used not only for efficient process control. They are also available for maintenance tasks and Big Data applications.
Another new feature is that the device description and the entire technical documentation of the field device are embedded directly in the device itself. This eliminates the need to laboriously search and download drivers and device information from the Internet, which significantly speeds up the development and commissioning of an automation system
References
1. www.fieldcommgroup.org/ETHERNET-APL Technical Paper, September 2020
2. Ethernet-APL Virtual Workshop | Customer Panel | Public – Presentation
www.pepperl-fuchs.com
Binoy Kamath is an Instrumentation Engineer with 25+ years of experience in Sales, Business Development, Key account Management, Technology Promotion. He has been working with Pepperl+Fuchs Group for the last 18 years. A senior Member of ISA-Bangalore, Binoy has presented papers and technology talks in various ISA, Fieldbus and End User events. He is currently involved in promotion of Ethernet APL technology, and digitalisation strategies in oil and gas, pharma and power plants, etc.