Fieldbus smokescreen? Helson responds

By Ron Helson, Executive Director, HART Communication Foundation

In the recent article by John Rezabek, “Users Driving the Bus”, John’s allegiance to Foundation Fieldbus is obvious, and that may be clouding his ability to properly represent the diagnostics capability of HART devices.

I’m not sure why “HART vs. Foundation Fieldbus” made the FF EUAC “Top 10” list, but I suppose it could be because users are starting to understand that the communications protocol is less and less a factor in the diagnostics capability of intelligent devices.

The term “FF-like diagnostics” as used by John is very interesting, since many of the initial and current FF registered devices are natively HART devices with an additional communication board to translate the data from HART to FF format. Consequently, the diagnostics in these devices is virtually identical.

The statement about “watered-down, fieldbus-like diagnostics” is also very ironic and misleading. Contrary to the implication, the fact is that all HART-enabled devices—dating back to the early 90s—contain device status and diagnostic information that is easily used by today’s HART-enabled automation and I/O systems without any upgrade to the device.

Users evaluating their automation system and field communication protocol options must consider many issues including, device replacement, training, project risk, infrastructure upgrades, automation and I/O system upgrades and others. In many cases, total cost vs. benefits have shown HART to be the most cost-effective option.

Users have a responsibility to their management to evaluate all their options for upgrading automation systems on brownfield sites including using the HART-enabled field devices that are currently installed. John’s implication that HART is not the most “promising technology of the day” is, we believe, incorrect.

Here are a few facts to set the record straight:

1. The real issue is taking advantage of the intelligence and diagnostic information available in smart field devices and using that information to keep plants competitive—not the protocol that is used to connect the device to the control system.
2. Very few, if any of the HART-enabled devices installed in user plants would require upgrade for their information to be integrated into control or asset management systems. The guiding principle for HART Communication Foundation is that all enhancements to the HART technology be backward compatible.
3. If users feel that they are getting a “smokescreen” when they ask suppliers to clarify the real capabilities and limitations of their proposed solution, they should consider another supplier or call the HART Communication Foundation for clarification.
4. Suppliers must provide several technology solutions because it’s to their advantage to be protocol independent in offering the best solution for their customers application. If HART happens to be the logical choice, that hardly qualifies as a “smokescreen.”

If you want to learn more about HART technology, the HART Communication Foundation can provide you with the facts to disperse the “smokescreen.”