In August 2011, IDTechEx published a survey, "Wireless Sensor Networks 2011-2021." In it, the researchers claimed that wireless sensor networks will grow from $0.45 billion in 2011 to $2 billion by 2021. Most of that growth will be in smart homes, smart grid and other non-industrial applications.
Raghu Das, CEO of IDTechEx says, "In 2011, industrial wireless sensor networks account for approximately 6% of the total $0.45 billion. In 2021, they will account for approximately 28% of the estimated $2 billion market."
"In 2011 I'd estimate WirelessHART to be 60% of that market segment that is industrial only," Das continued. It is difficult to predict its use in the future—the choice of standards is a problem."
A recent survey by Control magazine indicates that the prediction may well be easier than Das thinks. According to the survey, published in the August issue, end users have stopped waiting for the standards to be hashed out and have begun selecting WirelessHART over other standards. Part of this is undoubtedly true because WirelessHART is now the only international open standard for wireless sensor networks: IEC62591-WirelessHART.
As a further insight, the Control study showed that 18% of respondents said they didn't need wireless networks—any variable they needed badly enough was worth running cable to. If you remember that HART Communication is both wired and wireless, this is an important advantage to end users and asset owners. You can continue to use your wired HART systems and when there is a need, a WirelessHART network will fit right in.
Interoperability Makes WirelessHART Work
A unique feature of WirelessHART is its integration with the wired HART specification. Just as all HART instruments—including WirelessHART— have been interoperable and backward-compatible. You already know how to commission and calibrate the wireless versions, because you already have HART smart devices in your plant. There is no run-up learning curve.
"From the E+H perspective we support all standardized communication protocols which of course includes WirelessHART"says Endress+Hauser (www.endress.com) wireless product manager Jason Knuteson. "Our customers are continuing to ask for robust and flexibility solutions for difficult process applications they experience, and WirelessHART is a great answer to their needs!"
What does interoperability really mean? It means that any HART device of any kind will work seamlessly with all other certified and registered HART devices. Further, for its basic functions at least, any certified and registered HART device can be interchanged with any other similar device. So every HART temperature transmitter is interchangeable, and so forth. For WirelessHART, it means that any WirelessHART gateway can be used with any manufacturer's devices, and all devices can be used with any gateway.
The WirelessHART Ecosystem
Proprietary wireless systems and even some so-called standard systems generally have only one vendor. This can be very worrisome for the operator when selecting a wireless network for the plant. Since 2007 when it was introduced, the number of vendors producing registered and certified WirelessHART devices (the HART "Ecosystem") has been climbing—now numbering around 20. These vendors include the manufacturers of at least 80% of all transmitters, control valves, and online analysis equipment, such as Siemens, Endress+Hauser, Moore Industries International, Emerson Rosemount and Emerson Fisher.
"Siemens is continuing to see a strong demand for our WirelessHART products and solutions," says Michael Cushing, product marketing manager for Siemens Industry, Inc. (www.sea.siemens.com) "and our SITRANS products are the cornerstone to our portfolio. Cost and efficiency is driving this demand, as WirelessHART users eliminate significant costs of cabling and installation, and realize the convenience of faster commissioning and easier maintenance. We also have the ability to interface WirelessHART with other Siemens process instruments through our SITRANS AW200 adapter. Customers will continue to have the need for easy access to information from plant applications and operations, and WirelessHART is well-suited to provide diagnostic information on measured process values."
What this means for you is that you have much less risk selecting WirelessHART for your wireless sensor network than in selecting any other system. It means that WirelessHART is "future proof." You can be certain that the HART Communication Foundation will maintain the full backward compatibility that has become its hallmark.
So Who's Waiting?
You may not be waiting at all. According to the wireless study published in Control's August 2011 issue, 43% of respondents said they already had wireless field networks, while another 27% said they were planning to install them in the next 1-3 years. If that's the case, the next step is to learn how to design, configure, manage and operate IEC62591-WirelessHART sensor networks.
Setting Up WirelessHART
"The WirelessHART standard is built on proven industry standards," Executive Director Ron Helson says. "The radio uses the IEEE 802.15.4 standard and requires extremely low power, enabling the battery to last as long as 10 years in some applications. The radio operates in the same license-free 2.4 GHz band as Wi-Fi and many other wireless technologies. WirelessHART uses channel-hopping and channel black-listing to prevent interference and enable coexistence with other wireless networks, and a combination of star and mesh topology networking to ensure robustness in the presence of noise."