This article was printed in CONTROL's November 2009 edition.
Wireless Reluctance Not Just Psychological
I have to disagree with your assertion ( "High Wireless," Aug '09,) that the acceptance of wireless is just psychological.
I remember when Profibus was first introduced to us. The salesmen touted all sorts of savings, but failed to point out how we would diagnose this network when something went wrong. We tried it anyway and learned the hard way that commissioning a network of any size over any distance was a nightmare of swapping parts, terminating cables, guessing and so forth. Nobody understood this stuff well enough to get things diagnosed.
However, once test equipment became available and training followed, we had no problems installing Profibus. Today, we have fiber rings around our plants with Profibus. We own the test gear to know whether the fiber is any good, the Profibus cable is properly terminated, or the protocol is messed up.
My hesitation to accept wireless is the lack of any test equipment or training to diagnose problems. You alluded to this when you wrote about "physically seeing and manipulating...cables." However, you missed something huge—being able to see and manipulate those cables makes it possible to diagnose them when they fail.
That test gear and training is lacking in the wireless world. There are no equivalent test boxes to do what a traditional two- way radio service monitor did in old radio shops. There is no training. Once again, the control vendors have put the cart before the horse. I'm not going to meet anything half way if it means leaving my diagnostics capability behind.
Understand that I really want to use wireless gear, but it has to be something that I can validate. I have to be able to diagnose it if something goes wrong. And it has to be simple to fix.
I bought this once before. I won't make that mistake again.
Jake Brodsky, PE
Washington Suburban sanitary commission
Dancing Automation Engineers
I have to compliment you on your article, "Automation Profession: Dancing Backward in High Heels." (Sept. '09,) It was a very enjoyable article, and it really hit home with me.
I've worked with ISA and have been involved with many different aspects of process control (PC) at various companies during the last 20+ years, so I can relate very well to what you wrote.
I think the combination of the following: lean and mean companies requiring people to perform many different PC activities, which results in these people becoming very experienced in many things, making them extremely busy and in demand. This also means that they don't have time to contribute to ISA or other professional organizations. And this has caused ISA to fall behind in what it has to help automation professionals get ahead because it relied (in the past) on volunteers and companies to provide people to read/write specs, standards, etc. Granted it has the body of knowledge, but it needs so much more.
Also, colleges didn't offer this type of curriculum when I went to school (computers have advanced so much), but perhaps they do now, so ISA has had to fill this void—which it can't do. I think trade schools offer more PC training, and engineering firms do as well with their lunch-and-learns. Therefore, perhaps ISA should consider approaching these institutions to develop and market their books. The problem, however, will be getting people who can write to help ISA!
Anyway, keep up the good work. I get tired reading "dry" articles about process control.
Diane R. Barkin (formerly Harris)
Harris Automation Services, Inc.