Interested in linking to "Justifying HART investments to management"?
You may use the Headline, Deck, Byline and URL of this article on your Web site. To link to this article, select and copy the HTML code below and paste it on your own Web site.
THE HART DIFFERENCE
Two Simultaneous Communication Channels
35–40 Data Items Standard in Every HART Device!
OBVIOUSLY, no two plants are alike, and results that each can achieve through use of HART can vary widely. Based on their experience working with a wide variety of users, systems and instrumentation vendors have come up with a number of implementation tips to consider and pitfalls to avoid:
Implement Solutions Gradually
Emerson’s Cobb notes that HART can be effectively implemented gradually, by tiers, making it easier to budget investments over a long period.
”At the low end of investment, you can stay offline and simply monitor loops on a manual basis periodically. This can be done in the field with a handheld communicator or by hooking up a PC equipped with asset management software, including data on all your instrumentation,” says Cobb. “At the next level up, you can establish continuous monitoring via a separate asset management system. And, beyond that, if your plant has invested in a control system with HART I/O, you can bring the secondary variables directly into it.”
Rely on Existing Equipment
Rely as much as possible on existing equipment says Steve Todd, marketing director for Moore Industries, which manufactures HART multiplexers. "We've found that customers that stand to gain the most from HART technology are the ones that can leave as much existing equipment in place as possible, yet still make significant, cost-effective process improvements. For example, if a customer wants valve position feedback at the control room, he can go the traditional route and run additional wiring back to the control room that provides this data. This gets expensive fast. A second alternative, though, is for the customer to leave everything else alone, and install smart HART controllers on the existing valves. Then, extract the stem position data from the HART digital data using a HART interface instrument installed in the control room.”
Demand Interoperability From Vendors
“While HART is a very open protocol, not every company subscribes to it,” says Honeywell’s Raghavendra. “Consequently, buyers should make sure from their vendors that the field device and/or system fully complies with the protocol as defined by the HART Communications Foundation. Customers also should encourage their vendors to register their devices with the foundation.”
Be Specific About Your Goals
Be specific about how you want HART to meet your needs, advises John DuBay, instrumentation product manager for Meriam Process Technologies. “Predictive maintenance is a great story, but many end users aren’t sure what diagnostics they’re looking for. If you ask them about the specific diagnostic capabilities they’re interested in, they’re not always sure.”
Provide Easy Access to HART Data
To achieve the benefits of online configuration and diagnostics, operations and maintenance personnel need to cooperate. However, that situation often is the exception rather than the rule, says DuBay. “Not many operators are eager to open up access to their maintenance crews because they’re fearful that devices could be reconfigured incorrectly or by accident.”
Know Where the ROI is Coming From
Masoneilan Digital Product Specialist Sandro Esposito advises that users should not expect to get substantial maintenance-related ROI from new HART-enabled digital valves. “The big rate of return is on the existing valves,” says Esposito. “You can graph a valve's performance over time and see that it plateaus at a high level of performance when it's new. You want to know where's the drop-off from that plateau, and how steep it is.”
ControlGlobal.com is exclusively dedicated to the global process automation market. We report on developing industry trends, illustrate successful industry applications, and update the basic skills and knowledge base that provide the profession's foundation.