ISA100 wireless claims dismissed as "good marketing"
9 Dec 2009
Arguably the main selling point of the ISA100.11a wireless standard over its WIrelessHART alternative is that it supports functionalities such as video, WiFi and personnel monitoring - on top of doing everything that the rival standard can do in terms of sending and deliivering measurements and other data from devices across a network.
The Honeywell OneWireless industrial wireless network system, for example, offers a scalable infrastructure to support wireless-enabled devices located throughout process facilities. The network is said to support multiple industrial protocols and applications simultaneously and provides a single wireless network that is simple to manage and efficient to operate.The system also supports wired transmitters, mobile worker devices, as well as standard Wi-Fi and Ethernet.
Honeywell’s Rama Budampati, who is ISA100.11a technical editor for system management, adds: “We can support Foundation Fieldbbus, HART, Profibus, DeviceNet, and legacy protocols and send messages from those protocols over the wireless network. WirelessHART cannot do that. It can only support HART. This is important as customers want to make sure that, [given] all the money they have invested, they don’t want to take these out and put new devices in.”
Likewise, Henk van der Bent of Yokogawa Europe explains: “Whereas WirelessHART focuses on monitoring from HART-enabled field instruments, ISA100.11a offers the scope to cover everything from field instruments to control-room integration. Moreover, it is compatible with a variety of protocols including FOUNDATION Fieldbus, Profibus, Modbus and others as well as HART, and allows over 1000 devices in a network compared to only around 250 with WirelessHART.”
However, Peter Zornio, chief strategic officer of Emerson Process Management - part of a group of major vendors also including ABB, Endress+Hauser, Pepper+Fuchs and Siemens, that are backing WirelessHART - describes much of these claims as “clever marketing” on the part of the ISA100 camp.
ISA100 covers a family of standards for the application of wireless in total on the plant, explains Zornio, who joined Emerson from Honeywell just a couple of years ago. That, he said, includes field networks devices - which WirelessHart is targeted at - as well as plant networks which are high-speed networks using WiFi technology, Wimax etc.
“The part in ISA100 where we are really defining a new technology is really only the wireless sensor network or what we call wireless field networks, because the requirements in the process automation here are very specific and very different than in any other industry,” said the Emerson executive. For instance, he noted, noted that power consumption and reliability requirements of process companies are much higher than provided by any existing radio standard.
“So in that area we are defining an actual new technology for the process industries; WirelsssHART has defined one, and one piece of this ISA committee called ISA100.11a has defined one. That’s really the only place where there’s friction as these are both new technologies that have been defined specifically for the process industries.”
Zornio went on to argue that the other parts of ISA100, such as video and voice functionality, employ technologies that already exist and where companies such as Intel are spending given the many billions of dollars on development.
Citing the delivery of a full plant network architecture at Chevron Richmond, which has a Cisco mesh with a WirelessHART device mesh undernerath, Zornio said Emerson can deliver systems that are “very similar” to a complete ISA100 architecture.
“So it sound good that ISA100.11a covers the whole thing, but the fact of the matter is that Emerson and other companies have no issue with the other parts of ISA100,” , said Zornio. “The part where all the controversy [exists] is the network technology that goes into the devices. Here the ISA100.11a sub-commitee has developed a technology that is basically a duplication in functionality of what already existed in WirelesHART, but is technically different.”
Making a comparision with the battle between HD-DVD and BlueRay, Zornio said consumers didn’t really care about the technical differences between the two. What they wanted, he added, was one that worked gave a really good picture and had all the movie titles on it that you wanted to buy.
“The same thing is true here. Our customers want a good reliable functional technology and most importantly they want reliable products from suppliers they already work with today. In terms of what the technology functionally means to an end user, there aren’t too many [issues] that are really significant,” the Emerson expert concluded.
