1. PROGRAMMABLE LOGICAL CONTROLLER (PLC) PRESENTED BY:- Mrs. Bindu Thakral And Jaidev Singh

2. I NDEX Introduction PLC Basics PLC and Controls History Advantages of PLCs PLC Operation Comparison to Relay Logic Applications Conclusion

3. I NTRODUCTION Programmable Logic Control, or PLC as it is universally called, is the ‘work horse’ of industrial automation. A PLC is used to control, time and regulate the sequence. Many production processes are controlled using PLCs like – metal machining sequences, product assembly lines and batch chemical processes.

4. PLC B ASICS Programmable Logic Controllers (PLCs), also referred to as programmable controllers, are in the computer family. They are used in commercial and industrial applications

5. B ASIC PLC O PERATION PLCs consist of input modules or points, a Central Processing Unit (CPU), and output modules or points.

6. B ASIC PLC O PERATION ( CONT..) Pushbuttons (sensors), in this simple example, connected to PLC inputs, can be used to start and stop a motor connected to a PLC through a motor starter (actuator).

7. PLC AND C ONTROLS H ISTORY Large amount of work required connecting wires Difficulty with changes or replacements Difficulty in finding errors; requiring skillful/experienced work force When a problem occurs, hold-up time is indefinite, usually long o Too many moving parts

8. A DVANTAGES OF PLC S Number of wires reduced by approximately 80% Fast and easy error detection. No change in wiring to change program Needs fewer spare parts Cheaper when large number of I/O instruments are needed Less moving parts Compact Cost effective for installation/maintenance

9. C OMPONENTS CPU Memory Areas Circuits to input or output data Basically, a big box of math

10. S PECIFIC C OMPONENTS Input Relays (contacts) Output Relays (coils) Data Storage Internal Utility Relays Counters Timers

11. PLC O PERATION Continually scans ladder diagram Consists of 3 important steps

12. P LC SCAN :-

13. L ADDER L OGIC Definition Comparison to Relay Logic

14. D EFINITION One form of drawing electrical logic schematics Very popular for PLCs Originally invented for use with relays

15. C OMPARISON TO R ELAY L OGIC First used for technicians, electricians & engineers Still first choice for most technicians, electricians, etc.

16. R ELAY L OGIC L ADDER L OGIC

17. “Jog” function added to previous relay circuit 1 component added 3 wires added

18. Two status indicators added 6 additional wires

19. P ROGRAMMING Basics – NO/NC Contacts/Coils AND & OR Gates Timers and Counters Building a PLC Ladder Logic Programming

20. B ASICS NO Contact NO Coil (Output) NC Contact NC Coil (Output)

21. AND G ATE

22. OR G ATE

23. T IMERS Very simple concept, it times 2 basic types, on- delay and off-delay Still sends logic as its output

24. C OUNTERS Counts number of times a lever is pulled, a button is pushed, etc. 3 types Up Counter Down Counter Up-Down Counter

25. B UILDING A PLC/L ADDER L OGIC P ROGRAM To illustrate, will start in relay logic, convert to ladder logic at end Will need to remove/replace some components

26. Relay Logic converted to Ladder Logic Diagram Much fewer hard wired components Double Pole Pushbutton for Jog switched to Single Pole Instead of motor relays, PLC just checks state of motor output

27. A PPLICATIONS :- Manufacturing Industry Food Industry Textile Industry Plastics Industry And many other……

28. C ONCLUSION :- We can conclude that A lot of wiring work have been reduced Error detection has became fast and easy Size has been reduced Cost effective for installation/maintenance

29. THANKS Q&A