Existing field devices in the process industry typically rely on limited fieldbus network infrastructures, which hinder the implementation of data-intensive applications and make end-to-end Ethernet-based communication difficult. The process industry of the future therefore requires a new network standard that is capable of transmitting process data from devices via communication systems with the speed and flexibility of standard Ethernet and IP technologies.

With this in mind, Gestalt initiated the development of an Advanced Physical Layer (APL) in 2011. This layer should be independent of existing protocols and overcome existing limitations with network expansion and installation in hazardous areas. At the end of 2016, the IEEE Standards Association approved the IEEE P802.3cg project, which deals with the development of extensions to the IEEE 802.3 Ethernet standard (IEEE 802.3) for a two-wire Ethernet according to 10BASE-T1L. This should enable an extended range and use in hazardous areas. The draft of such an extended standard based on IEEE P802.3cg will also contain specifications for short-range applications and a solution for auxiliary power supply. The draft is expected to be finalized in 2018. The resulting addition to IEEE 802.3 is expected to be released in the second half of 2019.

... at the ODVA stand.

© Computer&AUTOMTION

The most important aspects of the APL project, which is running in parallel, include the goal of expanding the relevant IEC standards to include additional definitions that enable the installation of Ethernet devices in hazardous areas (Zone 0 and 1 / Division 1), as well as developing protocol-independent conformance tests for intrinsically safe adaptation to 10BASE-T1L. Once all IEEE and IEC standards and the associated field device conformity tests have been completed, this "Ethernet down to field level" should be ready by 2022. Dr. Jörg Hähniche, spokesperson for the APL project steering committee and Endress + Hauser employee, emphasized at the joint press conference of Profibus and Profinet International (PI), ODVA and the Fieldcomm Group at Achema 2018: "We have a strict schedule, but we are right on track!"

Ethernet up to field level uses technologies and options that are already established in process automation. This includes the tried-and-tested trunk-and-track topology. It can supply up to 50 field devices with up to 500 mW per device. Widely used and established cable infrastructures are specified to support the migration of existing systems to future Ethernet connectivity.

In addition to the organizations mentioned, the APL project is supported by several major suppliers to the process industry, including ABB, Endress + Hauser, Krohne, Pepperl-Fuchs, Phoenix Contact, Rockwell Automation, Samson, Siemens, Stahl, Vega and Yokogawa.