Figure 1: When asked "Which of the following field instrumentation technologies would you be most likely to use in a new plant? (Please check all that apply)," Control readers indicated a diverse mix of technologies including Ethernet-APL, which is slated to see first commercial implementations in 2021.
While the mix of field communication technologies deployed in the process industries has changed little over the past two decades, recent end-user workshops and surveys conducted by the FieldComm Group and Control suggest that may be about to change. Many end-user organizations see the potential benefits of emerging digital transformation technologies such as Ethernet-APL and a common plant-floor-to-cloud software information model for process automation instruments and systems. And they’re willing to give them a try.
Indeed, while 18% of Control readers from across the process industries list Ethernet-APL—the new two-wire, loop-powered Ethernet standard that accommodates intrinsic safety—as a technology “likely to be used in a new plant,” it ranked number five among other options listed, including perennial front runner 4-20mA + HART (Figure 1).
Meanwhile, workshop conversations conducted by FieldComm Group representatives in late 2019 with oil & gas industry users in the Middle East and Asia confirm continued support for trusted fieldbus and 4-20mA + HART technology for safety and control applications, relegating likely Ethernet-APL usage to non-critical monitoring applications—at least for starters. Development of personnel skills as well as security (how?) and reliability (unproven) were cited as key concerns to be addressed prior to broader adoption.
Current options still important
Clearly, part of users’ reticence toward embracing new field communications technology is a certain level of satisfaction with the current status quo. 4-20mA + HART and FOUNDATION fieldbus do what they were designed to do, and they do those tasks well.
Chief among the reasons cited by users to continue using traditional technologies such as 4-20mA + HART and FOUNDATION fieldbus is that they are well understood (require no new training) and are reliable and flexible, including backwards compatibility and interoperability with other equipment. These sunk investments—in intellectual property as well as installed base of systems and instruments—guarantee the continued use of current technologies for years to come.
But underutilization of HART instrument data beyond the process variable has long been a widespread complaint and opportunity. Over the past several years, Control’s reader surveys have shown a stable two-thirds of users to have advanced beyond using HART data only during instrument commissioning or calibration and are using it for other purposes such as device diagnostics and conditioning monitoring. But that access is hard won, and FieldComm Group workshop participants indicate there is yet valuable data in their instruments that they are not using effectively. Users also indicate that getting the information from the device to the desired consumer of that information both inefficient and challenging.
Single information model appeals
For example, while many end users indicate overall satisfaction with current instrumentation communication options, a full 75% of users paradoxically indicate that using devices from multiple vendors in the same system is “challenging” or “very challenging.” Major obstacles identified by process automation professionals in Control’s latest survey range from legacy systems with functionality limitations to the challenge of managing diverse device drivers and versions (Figure 2). So, apparently there’s still some work to be done on this front.
