The document explains the fundamentals of programmable logic controllers (PLCs), highlighting their advantages over microcontrollers, such as higher processing capacity and the ability to handle high voltage. It details the components of PLCs, their operating cycle, programming languages, and examples of input and output devices. Additionally, it covers the setup of Human Machine Interfaces (HMIs) and introduces SCADA systems in the context of traffic control.

1. Programmable Logic
Controller
MADE BY: ASIF ADNAN RASHID

2. What is PLC(Programmable Logic
Controller)
 PLC may be defined as micro-controller based controlling device that used to
store instructions in programmable memory to implement logic, sequencing,
timing, counting and arithmetic function through digital/analog input/output
modules for controlling device or process.
 Why PLC is used over microcontroller?:
I. PLC has more input/output than microcontroller. We can also extend input and
output module in PLC.
II. PLC processing capacity is lot more higher and faster than microcontroller.
III. We can change PLC module or restore data if it is problematic.
IV. PLC can work on high voltage but microcontroller faces some discrepancies
while operating in high voltage.
V. PLC has display unit and observe the current condition, but in microcontroller
we can use display as an add-in service.

3. Components of PLC
PLC consists of the following units: 1)Processor 2)I/O unit 3)Memory unit 4)Power Supply
5)Programming Unit

4. PLC Operating Cycle
 PLC automate a process by
I. Read Input
II. Program Scan
III. Energize the Output
IV. Continue the cycle
PLC can be divided into 3 parts:
I. CPU
II. Input/Output
III. Programming Device
When box reaches at the end of the conveyor,
sensor send a signal to PLC to stop the motor as
well as stop the conveyor.

5. PLC INPUT and OUTPUT Module

6. Signal of Input and Output Module

7. SIEMENS PLC

8. SIEMENS S7-1212C DC/DC/DC
Specifications

9. SIEMENS S7-1212C DC/DC/DC
Specifications

10. Family of S7-1200

11. Schematic Diagram

12. Addressing System

13. Peripheral devices of PLC
Input Devices:
1. Limit Switches
2. Proximity Sensors
3. Sensors
4. Relay
5. Solenoid
6. Photoelectric sensors
Output Devices:
1. Actuators
2. Lamps
3. Valves
4. Motors etc
Different Brand PLC

14. PLC Programming Language
International Standards for PLC specifies Three graphical and Two text-based languages for
programming PLC.
Language Abbreviation Type Application best
suited for
Ladder Logic Diagram LD Graphical Discrete Control
Function Block Diagram FBD Graphical Continuous Control
Sequential Function Chart SFC Graphical Sequencing
Instruction List IL Textural Similar to Ladder Logic
Structured Text ST Textural Complex Logic ,
Computational etc

15. Ladder Diagram Example

16. Motor Connection
Motor that is run by PLC is controlled in 2 ways. 1)Power Ckt (AC current) 2) Control Ckt (PLC
)

17. PLC Ladder Diagram
To On/Off a motor it should follow the undermentioned ladder diagram with latching:

18. HMI(Human Machine Interface)

19. HMI Function

20. HMI setup procedure
 Steps
-Browse PLC
-Continue up to finish(Untick select item)
-Take start, stop, load
-Set properties of elements, object
-Match with PLC tag table
-Simulation
-Download HMI

21. HMI Configuration

22. HMI….
Add memory block in program main block

23. HMI….

24. HMI setup procedure….

25. HMI setup procedure….
Press Start – Stop Switch

26. HMI Download
Press Right Button On HMI
Download Hardware and Software
Finish and check HMI screen

27. What is SCADA?

28. Advantages

29. Traffic Control with 2 roads

30. Ladder Diagram for Traffic Control for 2
roads

31. SCADA SIMULATION FOR TRAFFIC SIGNAL

32. THANK YOU FOR YOUR ATTENTION