Despite a public, 11th hour challenge from Honeywell, WirelessHart has become the first officially released industrial wireless communication standard. On Sept. 7, the Hart Communication Foundation (HCF) announced the official release of the Hart 7 Specification—which includes WirelessHart—following a vote by the HCF board of directors.
“With official release of the Hart 7 Specifications, the WirelessHart standard is now publicly available, and manufacturers can begin implementing this new capability into their products and process solutions,” said HCF Executive Director Ron Helson. “I expect that products complying with this new standard will be available from multiple manufacturers in early 2008.”
The HCF board vote authorizing release of the Hart 7 Specification came just two days after Phoenix-based Honeywell Process Solutions (HPS) issued a letter to the press urging HCF to remove WirelessHart from Hart 7.0. The letter, which was signed by HPS President Jack Bolick, recommended that HCF instead adopt ISA100 as the networking technology for Hart wireless deployments.
ISA100 is the industrial wireless networking standard being developed by the SP100 committee of the Instrumentation, Systems and Automation Society (ISA). A draft version of ISA100.11a—the first of an anticipated “family” of ISA industrial wireless standards—is expected for release in October.
Honeywell has one of five seats on the HCF board. In opposing the WirelessHart approval, Honeywell stated in its Sept. 5 letter its intention to “vote no on this particular issue.” Other companies with HCF board seats are ABB, Emerson Process Management, Endress+Hauser and Siemens. The HCF did not divulge the vote count, but an HCF spokesperson said that a simple majority, or at least three of the five board seat votes, was required to authorize the Hart 7 release. Various sources said unofficially that the vote was 4-1 in favor of the Hart 7 release.
In its letter opposing WirelessHart, Honeywell argued that unlike WirelessHart, which is designed to support only the Hart protocol, ISA100 is being developed as a universal network that will support multiple protocols. “…ISA100 supports implementation of protocols such as Hart, Profibus, CIP (Common Industrial Protocol) and Foundation Fieldbus on top of its flexible application layer. This obviates the need for single-protocol networks like WirelessHart,” Honeywell said.
In a response prior to the board vote, HCF’s Helson said the letter from Honeywell’s Bolick was “a surprise and disappointment to the [HCF]. The letter is counter to the view of the HCF staff and the HCF members who overwhelmingly approved the Hart 7 Specifications including WirelessHart during the extensive review and approval process that concluded in June of this year.” Helson noted that the enhanced Hart standard was created during a more than two-year-long process that involved leading companies in the process industry, including Honeywell.
In its press release announcing the Hart 7 release, the HCF bills WirelessHart as the first open wireless communication standard specifically designed for process measurement and control applications. And during a recent interview with Automation World, Helson said that he expects to see two “major use cases” for WirelessHart devices.
The first will involve wireless connection to existing, wired Hart devices using WirelessHart adapter products. This will enable end-users to gain wireless access to digital diagnostic data that is present with the 4-20 milliamp analog signal from Hart-enabled instruments, but is often not used in legacy distributed control system (DCS) implementations.
The second use case, Helson said, will enable a new class of wireless devices that are entirely self-powered, using batteries, solar power or other energy sources. These devices will be used for condition and performance monitoring of assets and parameters that may not have been measured or process-connected in the past, due to cost and wiring restrictions, Helson said.
The HCF announcement stated that WirelessHart technology addresses critical needs of the process industry for simple, reliable and secure wireless communication in the real-world industrial plant environment. The standard is easy to use, easy to deploy, and fully backward compatible with existing instrumentation and host systems, preserving the investment in Hart-enabled devices, tools, training, applications and work procedures used today, the HCF said.
Installed base protection
“WirelessHart provides the same experience that users know and expect from Hart-enabled products, protecting the global installed base of 24+ million Hart devices,” said Helson.
WirelessHart communication builds on established and field-proven international standards including the Hart protocol (IEC 61158, promulgated by the International Electrical Commission), EDDL, or Electronic Device Description Language (IEC 61804-3), the Institute of Electrical and Electronics Engineers’ IEEE 802.15.4 radio and frequency hopping, spread spectrum and mesh networking technologies. The new technology addresses the issues users face in the process plant environment and seamlessly integrates existing devices into Hart-enabled systems, according to the HCF.
WirelessHart technology was developed from user input through the combined, cooperative efforts of HCF member companies and leaders in wireless technology, including ABB, Adaptive Instruments, Crossbow Technology, Dust Networks, Elpro Technologies, Emerson Process Management, Endress+Hauser, Flowserve, Honeywell, MacTek, MTL, Omnex Control Systems, Pepperl+Fuchs, Phoenix Contact, Siemens, Smar, Yamatake and Yokogawa.
Hart Communication Foundation
Honeywell Process Solutions