I purchased one of the original iPod Shuffles back in 2005 for $149. It was completely functional and did everything I wanted it to do. That is until I played with an iPod that had a screen and I realized the Shuffle didn’t do everything I wanted it to do. The next iPod I purchased cost about $250. It really doesn’t do that much more than the original Shuffle except it has a screen and holds more. All of the iPods have fallen in price and competition heated up enough that you can purchase a cheap MP3 player for $5 or so now. Micro PLCs are kind of headed in the same direction.
Siemens recently launched their S7-1200 small form-factor controller and depending on the model, pricing starts around US$200. Rockwell Automation is launching a new MicroLogix 800 controller that will be in that same general price range depending on the feature set. Mitsubishi has their Alpha line. Omron the Sysmac CP1 and Automation Direct or Koyo have the DirectLogic or Click that is sold below US$100. How can a manufacturer provide a marketable PLC product that provides an adequate level of functionality for less than US$100.
The MicroLogix PLCs are a proven line of controllers and I assume the Siemens S7-1200 and several of the others are also functional. But somewhere in the list of available micro PLCs there are bound to be some real dogs. At this stage of my career it is pretty difficult for me to risk purchasing a micro PLC that I am not sure will hold up in my applications in order to save a couple hundred dollars.
Doug Brock has a broad range of factory automation and wholesale distribution experience and is an expert on the application of the Baldrige Criteria for continuous improvement efforts.
