By Ron Helson, Executive Director, HART Communication Foundation
In the recent article by John Rezabek, Users Driving the Bus, Johns allegiance to Foundation Fieldbus is obvious, and that may be clouding his ability to properly represent the diagnostics capability of HART devices.
Im 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 devicesdating back to the early 90scontain device status and diagnostic information that is easily used by todays 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. Johns 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:
- The real issue is taking advantage of the intelligence and diagnostic information available in smart field devices and using that information to keep plants competitivenot the protocol that is used to connect the device to the control system.
- 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.
- 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.
- Suppliers must provide several technology solutions because its 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.