Issue link: https://resources.mouser.com/i/1499776
Because of these shortcomings, factories that implement 4–20 mA are limited in the amount of data that can be communicated between field-connected devices, ultimately limiting process plant visibility and performance. Instead of 4–20 mA, many designers today are turning to a new protocol called Ethernet Advanced Physical Layer (Ethernet-APL). Ethernet-APL is the result of a group of leading industrial automation suppliers for the process automation market who came together to use 10BASE-T1L with extensions for installation within the hazardous areas of process plants. Importantly, this protocol is high-speed, bidirectional, robust, and reliable over long distances. Additional benefits of Ethernet-APL include Internet Protocol addressability through the Ethernet protocol and seamless integration into existing networks. In terms of the digital factory, a switch to Ethernet-APL has remarkable benefits for the process plant. Primarily, Ethernet-APL enables significantly higher-bandwidth communication within the factory floor and extends out to remote process node deployments, allowing for more and richer datasets to be shared between devices. In the context of sensors, this increased bandwidth means that more information can be shared than previously possible, including sensor metadata that provides more transparency on the factory floor. Additionally, bidirectional communication allows for power delivery to occur over the same cable as that for digital communication, resulting in less complex wiring schemes for networks and improved power delivery to field-connected devices. The shift from 4–20 mA communication to Ethernet-APL is a marked improvement, resulting in unprecedented functionality and insight into process plant operations. C h a p t e r 2 | S e a m l e s s C o n n e c t e d F i e l d I n s t r u m e n t s w i t h Et h e r n e t- A PL Ethernet-APL is an enhanced physical layer for single-pair Ethernet (SPE) based on 10BASE- T1L. It communicates via a cable length of up to 1000 m at 10 MBit/s, full-duplex, which is more than 300 times faster than technologies like HART or fieldbus." Karnakaran Thangapandiyan Automation Engineer, Rockwell Automation 11 Leading the Way to the Digital Factory