What is HART 7?

Is the latest version of the HART protocol strictly for wireless?

04/01/2011


Dear Control Engineering: Is HART 7 strictly a wireless protocol, or does it also cover wired devices? What version of HART are most manufacturers using with wired devices these days?

Given the number of protocols circulating these days, it's no wonder that they can get confusing. So we put this question to Ron Helson, executive director of the HART Communication Foundation. Here's his answer:

HART 7 is more than just a wireless protocol, the HART 7 standard applies to the full range of measurement, control, and automation systems products based on the HART Communication Protocol – whether wired or wireless. The WirelessHART capability is getting the most attention, but HART 7 provides many new capabilities beneficial to industry users in both wired and wireless products. Examples include:

1) Report by Exception—enables devices to push information to the control or asset management system without the system having to poll the device with a standard HART command. If there is a process or device status change, the device will automatically advise you.

2) Time-Stamped Data—a valuable tool that adds a time stamp to process data readings sent to the host system which is helpful in evaluating the sequence of events or analyzing problems that have occurred.

Each HART version builds on the functionality of the previous versions without taking anything away—the functionality of HART 5 is included in HART 6; the functionality of HART 5 and HART 6 is included in HART 7. HART Communication Foundation policies encourage manufacturers to design new devices and update existing devices to the latest HART version. Consequently many manufacturers are updating their device and systems products to HART 7. 

While this updating is going on, the vast majority of wired devices installed in user plants and available on the market today are built to the HART 5 standard. However, because all HART versions are backward compatible and interoperable with each other, the HART version is mostly transparent to the user. Each HART version builds on the functionality of the previous versions without taking anything away—the functionality of HART 5 is included in HART 6; the functionality of HART 5 and HART 6 is included in HART 7. This backward / forward compatibility preserves investments of both users and manufacturers as it enables a HART 5 control system to communicate with a new HART 7 device the same as it communicates with a HART 5 device. It also means that control system built to the latest HART 7 standard can communicate with all versions of HART devices – HART 5, HART 6 or HART 7. 

--Ron Helson, executive director of the HART Communication Foundation

www.hartcomm.org



No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Learn how to create value with re-use; gain productivity with lean automation and connectivity, and optimize panel design and construction.
Go deep: Automation tackles offshore oil challenges; Ethernet advice; Wireless robotics; Product exclusives; Digital edition exclusives
Lost in the gray scale? How to get effective HMIs; Best practices: Integrate old and new wireless systems; Smart software, networks; Service provider certifications
Fixing PID: Part 2: Tweaking controller strategy; Machine safety networks; Salary survey and career advice; Smart I/O architecture; Product exclusives
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Look at the basics of industrial wireless technologies, wireless concepts, wireless standards, and wireless best practices with Daniel E. Capano of Diversified Technical Services Inc.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.