I realize that you're trying to quote Schneider's latest sales pitch, but I lost track of that fact in your editorial ["Suddenly Impact?," Jul09, p9].
I find it very interesting that more and more companies are pushing the "green" sales pitch and, as you indicate at the end of your article, usually do not push the bottom line. I understand how the message could feel "substantial in its earnestness."
But I wanted to point you to alternative viewpoints at www.heartland.org and encourage you to check out "Is the U.S. Surface Termperature Record Reliable?" and "The Twenty Three (and Growing) Smoking Guns of Global Warming."
Paul Guidry, PE, project manager,
I read your Live Wire column ["Controls Choice Still Evolving," May09, p17] and was interested in any additional benchmarking information you may have about PC vs. PLC controls. I'm interested in why a vendor chooses one architecture over the other and their thoughts/justification in the decision-making process. Was there any additional data that you collected when researching this article? Have you compiled a listing of pros and cons to the debate? Any additional information would be greatly appreciated.
Matthew Wicks, PE,
Vice President—System Engineering
[Editor's Note: Here are four additional things you might find helpful. We ran a follow-up column with some more-specific anecdotal advice about the use of industrial PCs from some machine builders and a couple of vendors. We also did a recent survey that addresses this topic and created a video report of the results at www.ControlDesign.com/controllersreport. Also, if you scroll through the Machine Builder Spotlight videos at www.ControlDesign.com/mbs, you'll find a variety of individuals at companies explaining their machine automation and technology choices, including the controller platforms. We also ran an article on preferred controller platforms for machining centers a while back, which appears at www.ControlDesign.com/battleroyal]