This document provides an overview of programmable logic controllers (PLCs). It discusses the history of PLCs, how they were developed to replace relay-based control systems. The key components of a PLC including the processor, memory, and input/output modules are described. Examples of PLC programming languages and applications in industrial automation like machine control, food/beverage processing, and material handling are provided. Advantages of PLCs include fast operation, modularity, ease of maintenance, and improved productivity. Disadvantages include initial high costs and difficulty changing or replacing systems. PLCs have become widely used in industrial automation applications ranging from simple to complex control systems.

1. PLC
Programmable Logic Controller

2. Content
▪ History
▪ Definition of PLC?
▪ Why we use PLC ?
▪ Architecture of a PLC
▪ Components
▪ Relay
▪ Circuit diagram of relay
▪ Sample of relay
▪ Programing Language Of PLC
▪ Block Diagram
▪ Our Project
▪ Circuit
▪ Project video
▪ Advantage
▪ Disadvantage
▪ Area of Applications
▪ Conclusion
▪ Summery
▪ References

3. HISTORY
▪ PLC was introduced in late 1960’s.
▪ First commercial and successful programmable logic
controllers was designed and developed by modicon as a
relay replacer for General Motors.
▪ Earlier , it was a machine with thousand of electronic parts.
▪ Later in late 1970’s the microprocessor became and greatly
enhanced the role of PLC permitting it to evolve from
simply relay to the sophisticated system as it is today.

4. Definition Of PLC?
▪ Programmable Logic Controller (PLC) is an industrial
computer that monitors inputs, makes decisions based on its
program and controls outputs to automate a process or
machine.
 The automation of many different processes , such as controlling
machines or factory assembly lines, is done through the use of
small computers called a programmable logic controllers(PLCs).

5. Why We Use PLC?
▪ To reduce human efforts .
▪ To get maximum efficiency
from machine and control
them with human logic .
▪ To reduce complex circuitry of
entire system .
▪ To eliminate the high costs
associated with inflexible,
relay-controlled systems.

6. Architecture of a PLC
INPUT
Power
Supply
Processor OUTPUT
MEMORY INTERFACE

7. COMPONENTS

8. COMPONENTS
▪ INPUT MODULES accepts and converts signals from sensors into a logic signal
Ex. : Switches, Pushbuttons.
▪ OUTPUT MODULES that convert control instructions a signal that can be used by
actuators.
Ex. : lamps, alarm.
INPUT
(PUSH BUTTON) PLC OUTPUT
(INDICATOR LIGHT)

9. Three Phase Motor
Terminal Box
Driver Shaft
Cooling Fan
Stator
Rotor
StatorWinding

10. Connection Of Motor with PLC
▪ This is the basic connection of
Induction motor with PLC .
▪ Here we use a circuit breaker & a
three phase relay.
▪ We also use two push button for
start and stop.
▪ In plc we start an induction motor
at Delta connection so that motor
can get enough current to start
and then running motor in Star
connection.

11. Use Of Motor in Our Project
We use a three phase
induction motor with
500 RPM for our project
.

12. Relay
Frist ever Relay

13. Circuit Diagram Of Relay

14. Sample Of Relay

15. Programing Language Of PLC
PLC
Language
Ladder
Logic
Functional Block
Diagram
Sequential Function
Chart
Boolean mnemonics

16. Block Diagram Of Our Project
Liquid-1 Liquid-2
Mixture
Tank
Dump
Tank

17. Our Project
Automatic liquid
mixing machine for
industrial use.

18. CIRCUIT
Neutral Mood

19. CIRCUIT
Liquid Coming
Mood

20. CIRCUIT
Motor Starting
Mood

21. CIRCUIT
Dump Mood

22. Area Of Application
 Machine controls

23. Area Of Application
 Machine controls
 Food/Beverage processing

24. Area Of Application
 Machine controls
 Food/Beverage processing
 Car park &Train station
control system.

25. Area Of Application
 Machine controls
 Food/Beverage processing
 Car park &Train station control
system.
 Manufacturing, Packaging,
Palletizing

26. Area Of Application
 Machine controls
 Food/Beverage processing
 Car park &Train station control
system.
 Manufacturing, Packaging,
Palletizing
 Material handling

27. Area Of Application
 Machine controls
 Food/Beverage processing
 Car park &Train station control system.
 Manufacturing
 Packaging, Palletizing
 Material handling
 Textile,Travel,printing Industry
 similar Sequential task as well as
Process control etc.

28. ADVANTAGES
very Fast , High speed of operation.
Small physical size, shorter project time Reduced space.
inputs and outputs already inside the controller.
Low power consumption
designed to withstand vibrations,temperature,humidity,noise
etc.
Easy maintenance due to modular assembly and flexibility
Improves Productivity
Improves Quality

29. DISADVANTAGES
InitialCosts Are High
PLC hold only one copy of programmes
PLC DevicesAre Proprietary
Unemployment Rate Increases
There's difficulty with changes or replacements.
When a problem occurs, hold-up time is indefinite,
usually long, It's always difficult to find errors.

30. Conclusion
The PLC have in recent years experienced an
unprecedented growth as universal element in
industrial automation .
It can be effectively used in applications ranging from
simple control like replacing a small number of relays
to complex automation problems.
Today the PLCs are used for control & automation job
in a single machine & it increases up to full automation
of manufacturing / testing process in a factory.

31. Summary
In this presentation we have discussed about:
What is PLC.
Why we use PLC.
Description of PLC.
A project over PLC.
Area of application.
Advantages & disadvantages

32. References
Wikipedia
Industrial Control Handbook, Industrial Press
Inc.
W. Bolton, Programmable Logic Controllers,
Fifth Edition.
 Maher, Michael J. Real-Time Control and
Communications.

34. Any Question

35. The
End