PLC Programming

Programmable Logic Controllers (PLCs) are the major components in industrial automation and control systems. The controlling nature of PLC is ranging from simple- push button switching to a single motor to several complex control structures. The PLC programming is an important task of designing and implementing control application depending on customers need. A PLC program consists of a set of instructions either in textual or graphical form, which represents the logic to be implemented for specific industrial realtime applications. As programmed intelligence, a controller runs by itself through the software that it is programmed with, as well as to receive updated set points or supervisor commands from the SCADA system or local HMI.

A dedicated PLC programming software comes from a PLC hardware of specific manufacturer that allows entry and development of user application code, which can be finally download to the PLC hardware. This software also ensures Human Machine Interface (HMI) as a graphical representation of variables. Once this program gets downloaded to the PLC and if the PLC is placed in Run mode, then the PLC continuously works according to the program.

Choosing the right PLC can be overwhelming for most people but, ultimately, it all boils down to how many inputs and outputs you require, as well as reliability, serviceability, maintainability, cost, and long-term effectiveness.