PLC INTRODUCTION

1. PLC
&
SCADA

3. PLC (Programmable Logic
Controller) Basics
– A PLC is a solid state device designed to perform logic functions previously
accomplished by electro mechanical relays.
– A PLC is a digital computer used for automation of electro mechanical
processes such as control of machinery on factory assembly lines.
– Basically a PLC is a assembly of solid state digital logic elements designed to
make logical decisions and provide outputs.
– PLC’s are used for control & operation of manufacturing process equipment &
machinery.

4. PLC Block Diagram
Rack & Chassis

5. PLC Components
– C.P.U (Central Processing unit)
– a) Microprocessor
– b) Memory Unit
– C) Power supply Module
– Programming / monitors
– I/O Modules
– Rack & Chassis
– Optional units

6. PLC Input Module

7. PLC Input Module

8. PLC output Module

9. PLC output Module

10. PLC power supply Module

11. PLC power supply Module

12. Advantages of PLC
– Flexibility
– Implementing Changes
& Minimising errors
– Large quantities of
Contacts
– Low Cost
– Pilot Running
– Visual Observation
– Speed of Response
– Ladder / Boolean
Programming method
– Reliability &
Maintainability
– Simplicity of Ordering
Control Systems
– Documentation
– Security

13. –Newer technology
–Environmental Condition
–Fail Safe Operation
–Fixed Programming Applications
Dis-advantages of PLC

14. Applications of PLC

15. – Number of logical inputs and outputs
– Size of memory required
– Number of special I/O Modules required
– Scan Time
– Communications
– Speed and power requirement of CPU and
Instruction set
– Software's
– Manufacturers support and Backup
Selection Criteria of
PLC

16. Than “Q”