Ethernet has been expanding on plant-floors for years, but it wasn’t able to serve in the hazardous settings that are so prevalent in the process industries—until now.
“In my mind, Ethernet-APL is what allows single-pair Ethernet (SPE) to be deployed in hazardous environments, but it must be clearly understood that they’re very different,” says Dr. Vivek Hajarnavis, technology manager at Rockwell Automation and chair of the market advisory committee at ODVA. “It helps that APL’s standards are complete, and that two of Ethernet-APL group’s four standards development organizations (SDO)—ODVA and PNO—are ready to conduct conformance testing. This allows anyone to develop APL products, and they’re doing it.”
For instance, ODVA’s exhibit at Hannover Fair 2025 included a demonstration of five present or prototype Ethernet-APL devices, including Vegapuls 80 GHz radar level transmitter from VEGA, and StoneL Axiom position indicator from Valmet. They were joined or accompanied by two APL field switches from Phoenix Contact and Pepperl+Fuchs, and two programmable automation controllers (PAC) from Rockwell Automation and Schneider Electric (Figure 1).
Because Ethernet-APL lets instruments, remote I/O and field switches run on its common, 10 Mbps physical layer, it frees their capabilities from prior restrictions. Components with onboard computations power now have a reason to analyze multiple process variables because their results have someplace to go.
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“What’s going on now is no different from the transition legacy, hardwired I/O made to fieldbuses. Today’s economics and technical drivers remain the same: how to get more data, faster updates, increased intelligence and greater security?” says Hajarnavis. “APL can enable all of these by allowing Ethernet connectivity and performance in the hazardous environments where they couldn’t go previously. It also makes technical transitions easier by allowing users to reuse existing Profibus-PA, Foundation Fieldbus (FF) and Modbus wiring, such as FF Type A fieldbus cable. A DCS such as PlantPAX now has access to data that it never had before.”
Hajarnavis reports that, in the past, a simple optical sensor might only be able to report if it was running high or low via a single digital input. “This situation improved when the DeviceNet protocol enabled sensors to indicate if its lens was dirty,” he adds. “Now, EtherNet/IP lets devices and their users analyze multiple process values at high speeds, perform additional configuration tasks, and improve their security—and these are just some of the capabilities that APL is bringing to hazardous settings.”
