Safety Instrumented Systems / SCADA

Some Standards Committees Work -- and Work Well

When Was the Last Time You Looked at the Standard for Duplex and Fourplex Convenience Electrical Receptacles?

Walt BoyesBy Walt Boyes, Editor in Chief

ISA100 continues to be the poster child for dysfunctional standards committees. The ISA100.12 WirelessHART convergence task group has issued its report. It identified three different paths to convergence between the two standards, but committee infighting prevented the group from issuing a recommendation. In fact, the mere publication of the committee report was bitterly fought by the ISA100.11a faction to the point of a literal screaming, yelling, table-pounding temper tantrum. At this writing, it appears that the ballot to release the report narrowly failed, and the ISA100.11a faction has prevailed in its continuing efforts to make the protocol a separate and non-interoperable standard.

The fundamental takeaway is that end users who want to wirelessly enable their plant field devices will have the same difficult choice that has delayed implementation of fieldbus technology: Which standard to choose? The safest answer is "none of them."

But, once in a while, even a blind dog finds a truffle, and sometimes standards committees do what they are supposed to with little or no dysfunction. That’s what happened on Dec. 1, when the Fieldbus Foundation made public the results of ISA100.15’s work on backhauls. Called "Foundation for Remote Operations Management [ROM]," this fascinating architecture enables the use of a single fieldbus (based on Foundation HSE) that can integrate wired and wireless standard protocols and provide bidirectional communication to any of the integrated devices. The system demonstrated had Wireless HART, ISA100.11a, wired HART and Foundation fieldbus H1 devices all communicating to the DCS or SCADA system and interoperating on the same network.

Foundation for ROM is a great idea and a great achievement for ISA100.15. The only question right now is whether vendors will embrace the concept. If you like the idea and want to be able to use Foundation for ROM, call your vendor and ask for it, loudly.

For years, there have been two major methods of describing devices for fieldbuses. EDDL has been used in most HART and Foundation fieldbus devices, while FDT/DTM has been used primarily in Profibus devices, with some spillover into the HART regime. When the FDT Group, the HART Communication Foundation, the Profibus Nutzerorganization (PNO or PI), the OPC Foundation and the Fieldbus Foundation issued a statement that they were working on a means to converge the two methods, most everybody yawned.

Ah, but some standards committees actually work, and work well. Achim Laubenstein of ABB has guided the FDI Cooperation LLC to the point where it has nearly succeeded in the task of creating a converged standard for EDDL and FDT/DTM. In December, FDI standardization began in IEC SC65E/WG7, and the first draft of the FDI specification was published. By the end of 2012, Laubenstein believes that the move to a single device driver for all field devices will have been completed, and the IEC will have adopted FDI as a standard.

Why are the FDI Cooperation and the ISA100.15/Foundation fieldbus endeavors so important? Because, unlike the ISA100.12/ ISA100.11a debacle, these groups are movements toward single, unified standards for basic system architectures of automation and control systems. We no longer have the "luxury" of having to write multiple drivers for multiple vendors’ devices or multiple APIs to allow one communications protocol to talk to another.

None of these efforts is going to put cash to the bottom line—they need to be done one time. When was the last time you looked at the standard for duplex and fourplex convenience electrical receptacles? There is just one. One time and done.