Programmable Logic Controllers

PLC History & Development

Programmable Logic Controllers (PLC) have been originally invented for the U. S. automotive manufacturing market to replace relay logic systems. The automotive industry adopted PLCs initially for software revision that replaced rewiring connected with control panels was used during the changing of production types. Before PLC, the process to change and update facilities for its fresh model each year was very expensive and time-intensive since each and every relay had to be individually rewired.

In 1986, GM requested any proposal for a device that would electronically change this get across system. Winning this project bid, Dick Morely with Bedford Associates is known as the “father” of the PLC with the 084 PLC as the first product of its kind. Bedford Related founded the company Modicon to help promote and service its 084 PLC, which was later sold to the German company today known as AEG. Schneider Electric in France is now the existing owner of Modicon’s 084 PLC. The PLC has become a vital part of many manufacturing industries saving hours of time in addition to thousands of dollars, but the automotive industry continues to be perhaps the largest best place to source plc control panels customer.

PLC Functions & System Tools

PLCs primary perform is to electronically rewire the hard-wired control panels that will, otherwise, require that each of the hundreds and even thousands of relays be replaced individually. PLCs accept data from switches, detectors and controls to control and drive various machines plus devices. PLC functions have expanded from its simple replacement of relay logic circuits to more advanced features concerning PIP implementation. The benefits and functions of the PLC have become found in industries beyond automotive manufacturing, including food digesting, mining and environment control.

Early PLCs were developed to resemble a schematic design of relay logic (known as ladder logic) to help reduce the training required for technicians, even though some used more of an instruction list type of encoding. PLCs today may take the form of this ladder logic or perhaps state logic, a far more complex programming language. Ladder common sense is more often used today because it allows the PLC coder to more easily detect issues with timing of the logic collection. PLCs today are programmed used computer software which capabilities also as a troubleshooting tool for the PLC software.

PLC functions have evolved since the 084 to include motion handle, sequential relay control, process control, networking and allocated control systems. Today, PLC data handling, storage, connection tools and processing power is equal to that of a computing. In fact , there are desktop logic applications that when combined with I/O hardware can overlap some PLC functions, which may be a lot more beneficial in smaller facilities or less critical situations. The advantage to PLCs in the form of a desktop logic program is generally the lower cost.

However , practicality is one area avoiding some industries to still not yet fully adopt PLCs, particularly the heavy industry manufacturers due to concerns over computer help longevity, cost and durability in humidity, harsher temperatures and less stable environments. As expected, the PLC has transformed coming from its original functions to the more efficient PLCs used by sectors today. Developers have also branched off from the PLC together with introduction of Programmable Logic Relays (PLRs), offering related functions as the PLC with the same goal in mind.

Releated Post