Uncharacteristic Outbreak of Common Sense in Wireless Wars
Last months attempt by Honeywell Process Solutions president Jack Bolick to delay release of the HART 7 specification and with it the WirelessHART standard seems to have concentrated the collective mind of the automation industry wonderfully. Bolicks objection to WirelessHART was, ostensibly, that it was unnecessary, duplicating the provision for communicating with HART devices that will in any case be included in the forthcoming ISA100 standard.
Such duplication, said Bolick, creates confusion and slows innovation. While some have ascribed less noble motives to the Honeywell stand, many clearly agree with the diagnosis, but are coming up with a rather different prescription. Two weeks after going ahead with the release in the face of Bolicks protest, the HART Communications Foundation (HCF) announced that it had entered into an agreement with ISA to collaborate and investigate opportunities to incorporate WirelessHART into the work of the SP100 Committee. Within the agreement is a mutual copyright licensing arrangement which allows ISA100 to evaluate and consider the adoption of WirelessHART and gives HCF access to all ISA100 documents going forward.
The two organizations are also establishing a joint technical committee to assess the degree to which WirelessHART technology meets the ISAs objectives and whether it can be incorporated into what is now being called the ISA100 family of standards, although that term has ominous echoes of the multiple mutually incompatible protocols whose incorporation into IEC 61158 finally resolved the acrimonious battles over fieldbus. Nevertheless HCF executive director Ron Helson welcomed the new spirit of cooperation, adding that, We believe WirelessHART is the right technology for process measurement and control applications and collaboration with ISA for adoption into the proposed ISA 100 standards is the right thing for the industry.
Less than a week later, HCF also announced jointly with the Fieldbus Foundation and Profibus Nutzerorganisation (PNO) the launch of a cooperative project to extend their successful collaboration on the Electronic Device Description Language (EDDL) and develop a specification for a common interface to a wireless gateway. The project will be based on WirelessHART and the emerging SP100.11a standard and will include the development of use cases, requirements and specifications for wireless communication with intelligent field devices.
Users and potential users of wireless technology could be forgiven for asking why the process automation industry has had, once again, to peer into the abyss before this degree of cooperation has emerged. Why, for example, would it not have been possible for the ISA 100 committee in effect to delegate development of HART provision within ISA 100 to HCF from the outset rather than allow the development of the very real possibility that existing users of the worlds 25 million HART devices would have to choose between a WirelessHART protocol from HCF and a rival protocol for HART over wireless from ISA? Nor should they assume that this belated outbreak of common sense is permanent and will lead inexorably to the development of a single, unified standard.
Indeed precedent is hardly encouraging. If there is a happy ending, however, the seeming paradox is that it will be Jack Bolick and his letters that we have to thank. Is that what he intended all along?
Meanwhile, on Another Front
If you thought the agreement announced at Hanover Fair between the FDT Group and the EDDL Cooperation Team (ECT) to develop a common Field Device Integration (FDI) model would mark an end to name-calling and point-scoring between the respective advocates of the two technologies, then think again. Last months FDT Group User Forum in Antwerp heard the preliminary results of a study sponsored by WIB (Werkgroup voor Instrument Beoordeling), the Hague, Netherlands, based international association of automation end users, comparing the functionality of FDT/DTM and eEDDL for the integration of Foundation fieldbus devices. WIB commissioned Shell Global Solutions to perform the tests earlier this year, using a test set up comprising three different DCSs, three stand-alone tools and four field devices, all of which supported DD, eEDDL and DTM in various combinations.
The latest FDT Group newsletter reports that the initial conclusion is that FDT is an intrinsically more powerful technology. While both provide the data accessibility and functionality required to support commissioning of smart Foundation fieldbus devices, FDT/DTM offers extended functionality for both commissioning and maintenance, leading to a recommendation that FDT is the right platform for advanced applications and that users and vendors should not try to stretch the capabilities of eEDDL to perform tasks for which it is not fit but should exploit the opportunities to implement intelligence in DTMs. Quite where that leaves the FDI project is not made clear.
Emerson Steals HPS OneWireless Clothes
Its little more than three months since Honeywell announced its OneWireless solution at its Honeywell User Group (HUG) meeting in Phoenix. OneWireless was, claimed HPS president Jack Bolick, the the only wireless network a plant needs, the implication being that users who were rash enough to adopt other vendors solutions, particularly those based on the then putative WirelessHART protocol, would rapidly find themselves having to manage a plethora of potentially conflicting wireless networks with unspecified, but undoubtedly dire results. While competitors names were scrupulously excluded from such utterances, it doesnt take a genius to work out that the principle target of this approach has been Emerson, which has been selling its HART-based Smart Wireless device networking solution since last autumn in North America and last January in Europe, although in quite what quantities is less than clear.