Here i will explain you how to learn about PLC in short time, for that we have some prerequisites to understand about the PLC.
1. Digital and Analog Fundamentals
2. Boolean Gates
3. Electrical Fundamentals
4. Digital Logic Desgin
Now after having knowledge of all these fundamentals we will start from PLC, what is PLC ?
A Programmable Logic Controller (PLC) is an electronic device that takes input from the plant / machine via sensors and transmitters, executes the logic programmed in its memory and generates the useful outputs on actuators to control plant / machine.
Richard E. Morley of Bedford Associates had invented the first PLC as a consulting project for General Electric in 1968. Bedford Associates is currently named Modicon and is a supplier of PLCs.
Now have you ever think ? Why PLC ?
Any industrial machine or plant are being controlled by control and power circuits located at control and power panels respectively.
Before the invention of the PLC, control circuits were designed using hardwired relay logic.Hardwired relay logic has many disadvantages as compared to PLC logic.
There are mainly 3 part of PLC.
1. Input Module
2, Output Module
for the input and output module you can see that there are again 2 types of module.
1. Digital Input module
2. Analog Input module
So according to input and output signal we can connect module.
Now Input module is receive the signal from input like Switch, Proximity sensors or any digital sensors.
its senses the signals from IP module and gives signal to CPU and CPU generates one bit in its memory which called as Process Image Input (PII) and then CPU execute the program which we have already loaded in PLC and update process output Image (POI) and finally its generates signal to output module and output module is connected with final control elements like bulb, LED, Contractor or analog output.
For learning PLC SCADA and industrial automation online please watch youtube channel “Automation Revolution”.