Looking back on Control's first 25 years' coverage of intelligent instrumentation reveals one of most important examples of process control technology held hostage to human nature. The problems with delivering on the tremendous promise began before Control was so much as a gleam in publisher Nick Cappelletti's eye with the birth of the smart transmitter in the early 1980s. "Self-diagnostics, remote calibration and improved measurement accuracy were its key features," wrote editor Brian Wolske in November 1989. "The push for digital field communications was underway. Promising to be one of the prominent topics of the 1990s, digital communication is poised to replace traditional analog electronic signals as the transmission medium for field instruments."
Communications standards and distributed intelligence were among "What's Still Missing in Process Control" in January 1990. The problem was summed up succinctly by Thomas Swift, a senior engineer at Bethlehem Steel, who said, "The next transmitter I purchase, I want to be able to specify conformity to an ISA standard." It was to be many years before he might get his wish.
As shown in the accompanying timeline, the 1990s saw steady improvements in microprocessors and digital signal conditioning, but communications problems persisted. "Certainly, there are some amazing capabilities built into today's field devices," wrote senior technical editor Rich Merritt in September 2002, "But these capabilities come with bewildering complexity and a steep learning curve. Smart field devices also come with several networks, as the vendors try to figure out which are the best to install from a marketing point of view: HART, fieldbus, device buses, Ethernet or proprietary buses? And just when you thought you knew all the instrument bus options, along comes FDT from Germany, promising to organize everything in the bus world." Virtually every instrument maker puts a highway addressable remote transducer (HART) interface into its field devices, but that's not enough, Merritt wrote. "Smart instrumentation desperately needs some standardization…Perhaps it's time for an ISA committee to step in."
Through 2000s, developments in HART, electronic device description language (EDDL), Field Device Tool/Device Type Manager (FDT/DTM) and object linking and embedding (OLE) for process control (OPC) made it possible, if not always practical, to get information from intelligent instruments into control systems.
In September 2011, the five major automation foundations—the FDT Group, Fieldbus Foundation, HART Communication Foundation, Profibus and Profinet International and the OPC Foundation—founded FDI Cooperation LLC to further development of a single, common solution for field device integration (FDI). FDI technology is to provide a common solution for managing information of intelligent field devices for the various tasks associated with all phases of their lifecycle from configuration, commissioning and diagnostics to calibration. In November 2013, FDI Cooperation released a Field Device Integration (FDI) specification and a demo of FDI developer toolkits, both designed to allow automation suppliers to develop products and host systems compatible with FDI.
Perhaps the next 25 years of intelligent instrumentation will be more about intelligence and less about communication.