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WirelessHART: Yes or no?
September 6, 2007

There's been a  lot about wireless lately with our Wireless in Process Manufacturing Webcast yesterday (which will soon be available in an archived version) and the big wireless supplement with our August issue of Control Engineering.

This morning I fired up my email and there was a message waiting that said Jack Bolick from Honeywell Process Solutions had sent me a letter-to-the-editor on the topic of WirelessHART. When I see something like that from the president of one of the major suppliers in our industry, it gets my attention. Long story short, he contends that the scope of the WirelessHART protocol is too limited and wireless users should throw their support behind SP100 with the intent of creating a more comprehensive protocol. The analogy he used is why would you buy a beeper when you can have a cell phone? My colleague Mark Hoske turned his letter into a news item which we posted. We have even updated it with a response from the HART Foundation, which you can also read.

I spoke this afternoon with Jack Bolick and Jeff Becker (listen to a podcast with Jeff) to get more information. I have to listen to the discussion again, but Jack was realistic enough to admit that his efforts probably won't sway the vote against approving the next phase of the WirelessHART protocol, but he is hoping to create dialog among potential users and get them to look at the larger picture.

As I try to get a handle on the moment, I have been thinking about the wireless article in the August issue, including a discussion of WirelessHART. It always seemed to me that protocol was pretty big for the relatively simple capability to convey HART data wirelessly. What Ron Helson and Wally Pratt told me while I was doing the article was that they are creating a framework which will bring all the functionality, tools, practices and interoperability of wired HART into the wireless world. That's certainly a worthwhile ambition.

I don't want to put words in Honeywell's collective mouth, but I think their message is that having HART capability is a good thing, but it shouldn't be foundation stone on which you build your wireless architecture. HART diagnostics are valuable, and they can be communicated via wireless, but that shouldn't be the tail that wags the dog. SP-100 is the dog. HART is the tail. You don't normally choose a dog on the basis of its tail. Customers who begin with WirelessHART may find that they don't have much to build on if they start looking beyond clusters of individual instruments.

OK, that's enough about dogs. There will likely be a more cohesive discussion on this topic in subsequent blog entries and in Process Instrumentation and Sensors two weeks from today. Stay tuned.

Posted by Peter Welander on September 6, 2007 | Comments (1)