Programmable Logic
Controllers

Almost every established manufacturing process has several things in common:

•     Firstly, the finished product, no matter how (seemingly) simple and unpretentious, is a result of (sometimes many) individual steps or processes. 
•     Secondly, over the years, many of these steps have become partly or fully automated. This was accomplished with custom designed control systems consisting of combinations of Relays, Electronic components and often, - Very complicated wiring. If something went wrong (and it often did) it meant expensive down time while troubleshooting and obtaining replacement components.
•     And Finally, Most of these processes can be Drastically simplified and improved with Today's Technologies.

    Programmable Logic Controllers (will be called PLC's hereafter) have been around in one form or another since the 60's. These devices were introduced to replace complicated proprietary control systems. They were devised to fill a need for a more "standardized" (we'll get to that later) means of controlling systems, often replacing Huge Banks of Relays with smaller, more readily available components. The basic idea here was to simplify Construction, Troubleshooting and Repair of Control systems with these "Standard" Components.

    The PLC is basically a Multipurpose Controller whose behavior can be controlled or "programmed" as needed. With the use of PLC's, if a process control had to be modified it could be done without expensive rewiring or hardware replacement. If a problem occurred it could mean simply plugging in a readily available Replacement. These reasons, coupled with increased reliability make the PLC the choice for controlling machinery and processes.

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