The progress to standardization of wireless systems continues, as you might expect, to march down the several different directions that each supplier feels suits its business model best. The ISA100.12 committee, revitalized by a user revolt last year, met alongside the ARC Forum in Orlando to review three proposals as to how to establish a future working relationship between the polarized opinions.
A report of this meeting by Walt Boyes on his ControlGlobal SoundOff! blog suggests that the first group, the "Heathrow Group" of WirelessHART enthusiasts—ABB, Emerson, Endress + Hauser and Siemens—suggests the IEC62591 could be upgraded to include the useful aspects of ISA100.11a and the Chinese WIA-PA standard.
The second group, the ISA100.11a enthusiasts—Honeywell, Invensys, Nivis, Yokogawa, Fuji, Hitachi and Yamatake—say we only want an ISA100 approach because it covers everything (that we suppliers want to see in there).
The third group is GE, standing alone, suggesting rewriting ISA100.11a to be an umbrella standard under which IEC62591, ISA100.11a as it exists at present and WIA-PA are capable of being used in the same network framework with the same backhaul.
So What's New?
The INSIDER in July 2010 applauded the Nivis announcement that it could offer a dual WirelessHART/ISA100.11a gateway, which enables the essence of the proposal made by GE. The impression from discussions with Rockwell and Honeywell has been that their plant automation systems will be made capable of dealing with whatever wireless standards are appropriate or in use on their customer’s plant. After all that is their business capability, or even a requirement for their business.
The inclusion of Invensys in the ISA100.11a group seemed surprising, given its broad tolerance to working with any system, as also expressed in response to questions at OpsManage last year. Indeed, its whole approach to the InFusion Enterprise Control System also requires the capability to work with communications via all available interfaces and systems, so does this apparently new alignment alongside the ISA100.11a protagonists signal any change of view?
The response from Hesh Kagan, whose current job title at Invensys is "Portfolio Architect, Technology Innovations," provided via Stephen Ballard of the Invensys UK PR agency was that "Invensys has been supporting the development of ISA100 as an open standard since the beginning. We believe the ISA100 architecture is consistent with our view of enterprise wide industrial wireless and the overall ECS concept. The development of ISA100 was accomplished with the participation of many WirelessHART proponents and includes all of the functionality of HART plus many other functional capabilities required to meet the current and future application requirements of our users."
Interestingly Kagan was reported in the INSIDER of October 09 as saying that "I do believe in meeting your customer's needs" and predicted the rapid emergence of a multitude of gateways and other devices to enable networks based on the two standards to coexist within the same environment. That said, his own preference was clearly for ISA 100.11 which, he said, in contrast to WirelessHART, provides "a lot of headroom" for the development of a much wider range of potential applications.
Looking back still further, to the INSIDER three years ago (August 08), shows a little more of Kagan's insight, when he said: "My belief is that this technology becomes compelling at the point where it reaches the top of the 'S' curve in three to five years time. At that point activity becomes frenetic."
For 2011, Kagan adds a different viewpoint on the Orlando discussions last month. "We (Invensys) are additionally participating on the 'Heathrow' team to try to reconcile differences between the ISA and WirelessHART standards to achieve one standard. We presented (with Honeywell and Yokogawa) a joint proposal to add a HART communications object to the ISA100 protocol at the recent ISA100.11a meeting in Orlando. We think that this creates the best overall solution for convergence and a unified wireless architecture."