The document provides an overview of Programmable Logic Controllers (PLCs), detailing their history, function, architecture, components, programming languages, advantages, and disadvantages. PLCs automate processes and improve efficiency in various applications, evolving significantly since their introduction in the 1960s. It also includes a discussion on a specific PLC project and its relevance in industrial automation.

1. Programmable Logic Controller
Prepared by
Tahmid Rongon and Ahad hossain

2.  History
 What is PLC ?
 Why PLC ?
 Architecture of a PLC
 Components
 Programing Language Of
PLC
 Ladder Logic
 Programming Example
 Block Diagram
 Our Project
 Circuit
 Project video
 Advantage
 Disadvantage
 Area of Applications
 Conclusion
 Summery
 References

3.  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.  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).
 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.

5.  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. INPUT
Power
Supply
PLC OUTPUT
MEMORY INTERFACE

8.  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.  Most common languages encountered
in PLC programming are:
1) Ladder Logic.
2) Functional Block Diagram.
3) Sequential Function Chart.
4) Boolean mnemonics.

10.  The ladder logic is the oldest programming
language for PLC.
 It is well suited to express Combinational logic.
 The main ladder logic symbols represent the
elements :

11. Ladder Logic Program for Start/Stop of Motor :

12. Liquid-1 Liquid-2
Mixture
Tank
Dump
Tank

13. Automatic liquid mixing machine for industrial use.

14. Neutral Mood

15. Liquid Coming Mood

16. Motor Starting Mood

17. Dump Mood

18.  Machine controls

19.  Machine controls
 Food/Beverage processing

20.  Machine controls
 Food/Beverage processing
 Car park & Train station
control system.

21.  Machine controls
 Food/Beverage processing
 Car park & Train station
control system.
 Manufacturing, Packaging,
Palletizing

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

23.  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.

24.  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

25. Initial Costs Are High
PLC hold only one copy of programmes
PLC Devices Are 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.

26. 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.

27. 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

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