Applications for WirelessHART Field Networks

There’s a great article on The Institution of Engineering and Technology‘s website, Industry Unplugged, by Emerson’s Mike Ferris. Mike is with the Smart Wireless team in the Rosemount Measurement business of Emerson Process Management.

Mike’s conclusion describes why process manufacturers might consider wireless field networks (a.k.a. wireless sensor networks.) He writes:

Wireless offers the ability to add additional measurement points to previously unreachable or unaffordable places throughout the process plant. This means greater access to information about the process and also the health of devices. Wireless mesh networking solves the problem of reliability within tough non wireless-friendly areas. Security issues have been addressed and in WirelessHART the process industry has an open standard to work with. By adding plant wide wireless networks it is now possible to improve the availability of this extra data to those that need it most.

Mike notes the adoption of wireless networks in our homes and offices and how it has become a part of our daily lives. This has not been the case in process manufacturing plant applications. A number of reasons he cites include a limited range of sensors and transmitters for acquiring data, security concerns, power concerns, and a lack of industry standards. Most wireless solutions were point-to-point, which prevented the ability to scale if the application required it.

These concerns led to the WirelessHART standard that I discussed in an earlier post. The architecture scales, installs in a straightforward way, and has well thought through security. For more on the underlying IEEE standards and protocols, this data sheet provides a good summary.

The main objective of WirelessHART is to be fully complementary to the wired HART standard. As such, it extends standard functionality like electronic device description language (EDDL) and provides process manufacturers a similar user experience whether the HART device connects wirelessly or via wires.

In the article, Mike offers application examples as opportunities where process manufacturers might give wireless field networks a try. I’ll summarize his ideas in a bulleted list:

  • Applications not justifiable when wiring installation costs included
  • Remote devices in hard-to-reach areas
  • Uninstrumented operational blind spots
  • Existing HART devices with no way to deliver diagnostic information
  • Manual readings done in hazardous locations
  • Automating operator rounds
  • Incremental measurement points
  • Measurements on rotating or moving plant equipment (ex. lime kilns, rail cars, portable skids, etc.)
  • Safety relief valve emissions monitoring
  • Safety shower flow

Of course, many of these examples are possible. It’s more the case that they are not practical once you factor in the wiring installation. It’s kind of like your home. Some things are more trouble than their worth to do when wiring is involved. With a wireless option, things get a whole lot simpler and more doable.

Posted Wednesday, April 23rd, 2008 under Wireless.

4 comments

  1. “Wireless offers the ability to add additional measurement points to previously unreachable or unaffordable places throughout the process plant”
    Feedback and information always helps organizations from repeating the possibilities of recurring malfunctions within their operation of business.

  2. Good point! It’s usually what you can’t see or measure that the source of the problem.

  3. DUANE LEE MARTIN says:

    Can you help me with WirelessHART for PLC applications?

  4. Hi Duane, Thanks for your question. You can use a gateway like the Rosemount 1420 Wireless Gateway and connect to your PLC via MODBUS or OPC. The link goes to the product data sheet that describes this in a little more detail.
    Whatever your ultimate solution, let me know how it works for you.
    Take it easy, Jim

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