Automation uses three basic steps: decision making, execution, and monitoring. The first step involves choosing what should be automated and then writing the code for it. This step is followed by the execution phase where all the instructions are carried out without any human intervention. Finally, we monitor how things are going to make sure that everything is running smoothly before we move on to another process.
Ladder Diagram (LD), also known as Relay Ladder Logic, is the most common programming language for PLCs (RLL). This is a graphical language for representing logical links between inputs and outputs as contacts and coils in a hard-wired electromechanical relay circuit.