1. Plc & scada applications
Role of Automation in Industry
Benefits of Automation
Necessity of PLC
Definition of PLC
History & Evolution of PLC
Types of PLC
Selection Criterion
Overall PLC System
PLC Input & Output Modules with Interface
CPU
Programmers
Power Supplies
Solid State Memory
Advantages & Disadvantages of PLC

2. Role of Automation
To Utilize the computers & controllers for controlling of process parameters
To increase the reliability & efficiency of system by replacement of no. of employees with machines
To increase the rate of production
To reduce the costing of process
To increase the quality of work.

3. Benefits of automation
Increase in productivity
Reduction in no. of Labour required
Enhanced Accuracy of work
Restless system operation
Ease in data collection

4. Necessity of plc
Gaining the control of manufacturing process
Consistency of operation
Improving the quality & accuracy
Work in difficult & hazardous atmosphere
Increase in productivity
Inventory of the process
Quick change in product.

5. Definition of plc
PLC is the solid state member of computer family that uses IC’s instead of electromechanical devices to implement the control functions of a System/ Process.

6. History & evolution of plc
The Hydramatic Division of the General Motors Corporation specified the design criteria for the first programmable controller in 1968.
To eliminate the high costs associated with inflexible, relay-controlled systems.
1968 Programmable concept developed
1969 Hardware CPU controller, with logic instructions, 1K of
memory and 128 I/Os
1974 Use of several (multi) processors within a PLC – timers
and counters; arithmetic operations; 12K of memory and I/Os
1976 Remote input/output systems introduced
1977 Microprocessors - based PLC introduced
1980 Intelligent I/Os developed with communication facilities
1983 Low Cost Small PLC Developed
1985 Networking of PLCs, Computer & Machines with the SCADA system

7. Types of plc
Micro PLCs : 32 I/Os
Small PLCs : 32 to 128 I/Os
Medium PLCs : 64 to 1028 I/Os
Large PLCs : to 4096 I/Os
Very Large PLCs : to 8192 I/Os.

8. Selection criterion
No. of I/Os
Memory of CPU
Scan Time
Communication
Availability of Program Software
Special Arrangements such as distance between machine & panel
Physical Environment

9. Overall plc system

10. Overall plc system

11. Input module

12. output module

13. Cpu Bitwise Performance Scan Time Diagnostics of System
Control of Process
Bitwise Performance
Scan Time
Diagnostics of System

14. Programmers – Mini programmers

15. Power supply
As per rating of the PLC
Also monitors & controls the supply voltage
Sustain 10-15% tolerance
Also has diagnostic feature
Const Voltage Transformer
Isolation Transformer

16. Solid state memory
Executive Memory Area
Application Memory Area
ROM
RAM
PROM
EPROM
EAROM
EEPROM

17. Advantages Flexibility Faster response time
Implementing changes & Error Detection
Lower Cost
Large no of Contacts
Pilot Running
Visual Operation
Easy Programming
Reliability & Maintainability
Documentation
Communication Capabilities
Small Size

18. disadvantages
High Capital Investment
Fixed Program Application
Fail Safe Mode