The process industry is moving toward the use of Ethernet to replace 4-20mA interfaces. This paper explains how to connect to an increased number of low power field or edge devices with a 10BASE-T1L MAC-PHY. It will also detail when to use the MAC-PHY vs. a 10BASE-T1L PHY and how these systems meet the requirements of tomorrow’s Ethernet-connected manufacturing and building installations.

Single-pair Ethernet 10BASE-T1L use cases, including Ethernet-APL, continue to expand across process, factory, and building automation applications driven by the requirement to connect more devices to Ethernet networks. With more devices connected, richer datasets are made available to the higher level management systems, leading to significant increases in productivity while reducing operating costs and energy consumption. The vision of Ethernet to the field or edge is to connect all sensors and actuators to a converged IT/OT network.

To achieve this vision, there are system engineering challenges, as some of these sensors are limited in power and space. There is a growing market of low power and ultra low power microcontrollers with significant internal memory capabilities for sensor and actuator applications. But most of these processors have one thing in common—with no integrated Ethernet MAC, they don’t support an MII, RMII, or RGMII media independent (Ethernet) interface. A traditional PHY cannot be connected to these processors.