I asked Ron, after he shared some concerns with me about John Rezabek's column, "Users Driving the Bus" in our April issue, to write a letter to the editor and share those concerns with all of you. I've lightly edited Ron's response, but his points are clear, and, more importantly, extremely valid. (If you really care, I took out all the name-calling, in the interest of civility---[evil grin]--although there wasn't even much of that, considering how forcefully Ron "shared his concerns" with me yesterday!). But seriously, folks, I agree with both John and Ron. John's position that there is a bunch of smoke being thrown around about HART capabilities is true. Ron's response to suggest that end users contact the HART foundation is the correct response to smoke throwing. And Ron's points about the diagnostic capabilities of HART devices are extremely valid. In fact, one of those little known facts emerged from Ron's letter, as you'll see when I get done pontificating and you can read the darn thing for yourself: many, if not most, of the FF devices currently available are HART enabled with an additional circuit board for FF. So, many "FF diagnostics" are in fact HART diagnostics as well. Nobody should lose sight of the point that, whether anybody likes it or not, the facts are clear: HART is the users' choice for brownfield plants unless you are going to do a gut-and-replace-everything rebuild. And looking at what will likely be the forthcoming HART 7 specification, currently in early draft form, it is pretty clear that there are some serious innovations, including Wireless HART coming this year. And HART will drive the wireless marketplace in process automation, regardless of what SP100 does, for at least the first few years. That's not debatable. That's just a fact. So, without further ado, heeeeeeeeere's Ron!
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 90's - 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, not correct.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." Ron Helson Executive Director HART Communication Foundation