Published on

Prgrammable Logic Controller

Published in: Technology, Business
No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1. Programmable Logic Controllers
  2. 2. Organization of the Presentation <ul><li>Introduction </li></ul><ul><li>Components of PLC </li></ul><ul><li>PLC Functioning </li></ul><ul><li>PLC Programming </li></ul><ul><li>Example Problems </li></ul><ul><li>Applications </li></ul><ul><li>PLC Selection </li></ul>
  3. 3. Introduction
  4. 4. PLC Defined <ul><li>Programmable Logic Controller (PLC) is a solid state device designed to perform logic functions. </li></ul><ul><li>Essentially PLC is an assembly of solid state digital electronic elements designed to make logical decisions and provide outputs </li></ul>
  5. 5. Why PLC <ul><li>Relay based Process or Machine Control is expensive and Rigid </li></ul><ul><li>Need for programmable and reconfigurable control </li></ul><ul><li>Move towards Flexible Automation </li></ul>
  6. 7. Areas of Application <ul><li>Process control </li></ul><ul><li>Control of Machinery </li></ul><ul><li>Control of Equipments </li></ul><ul><li>Certain Aspects of Control in CNC machines and Machining Centers </li></ul>
  7. 8. Components of PLC
  8. 9. PLC Components <ul><li>Any PLC Has </li></ul><ul><li>1. A Central Processing Unit (CPU) </li></ul><ul><li>Microprocessor based system </li></ul><ul><li>2. Input / Output Section (I/O Section) </li></ul><ul><li>Digital and analog I/O s </li></ul><ul><li>3. Programming Device </li></ul><ul><li>Usually a Computer </li></ul>
  9. 10. PLC Components
  10. 11. PLC Functioning
  11. 12. PLC’s Perform Scans Sequentially and Cyclically
  12. 13. Typical PLC Scan Sequence
  13. 14. PLC programming
  14. 15. Typical Inputs and their Representation
  15. 16. Inputs (Continued )
  16. 17. Inputs (Continued )
  17. 18. Inputs (Continued )
  18. 19. Inputs (Continued )
  19. 20. An Electro Mechanical Relay
  20. 21. Typical Outputs and Their Representation
  21. 22. Timers <ul><li>On Delay Timers </li></ul><ul><li>Off delay timers </li></ul><ul><li>Retentive Timers </li></ul>
  22. 23. Counters <ul><li>Up Counters </li></ul><ul><li>Down Counters </li></ul><ul><li>Up Down Counters </li></ul>
  23. 24. Relays <ul><li>Internal Relays </li></ul><ul><li>External Relays </li></ul><ul><li>Retentive Relays </li></ul>
  24. 25. Example Programs
  25. 26. Design a Control Program for a Water Pump Motor
  26. 27. Product in Position (LS1 Close) Start button on. Conveyer moves product to A (Limit switch LS1 returns to normal) Conveyer moves the Product to A and stops Distance to A counted by encoder (8 Pulses) Waits at A for 10 s Moves again to LS2 and stops Emergency stop Emergency stop resets counter and timer
  27. 29. Applications
  28. 30. Process Control <ul><li>Electroplating </li></ul><ul><li>Heat Treatment </li></ul><ul><li>Powder Coating </li></ul><ul><li>Chemical Processing </li></ul><ul><li>Refineries </li></ul><ul><li>Control of Hydraulic and Pneumatic Circuits </li></ul>
  29. 31. Control of Machinery and Equipment <ul><li>Control of Material Handling Equipments like Conveyer Belts </li></ul><ul><li>Control of Flexible, Automated Assembly Lines </li></ul><ul><li>Control of Special Purpose Machines like Bottling Machine etc. </li></ul>
  30. 32. CNC Machines <ul><li>velocity, displacement and position control is being carried out by exclusive controllers (Hardware interpolators, Closed Loop Controllers etc..) </li></ul><ul><li>Mostly all ‘M’ codes are transferred to PLC Control </li></ul><ul><li>PLC Provides one more level of Protection in CNC Machines </li></ul>
  31. 33. Machining Centers <ul><li>Automatic Tool Changers </li></ul><ul><li>Automatic Pallet Changers </li></ul><ul><li>Overall system protection </li></ul>
  32. 34. PLC Selection
  33. 35. Criteria for Selecting PLC <ul><li>Number of logical inputs and outputs. </li></ul><ul><li>Memory </li></ul><ul><li>Number of special I/O modules </li></ul><ul><li>Scan Time </li></ul><ul><li>Communications </li></ul><ul><li>Software </li></ul>
  34. 36. Typical PLC Specification
  35. 37. Commercial PLC Manufacturers <ul><ul><li>Omron Electronics Inc. </li></ul></ul><ul><ul><li>Allen Bradley </li></ul></ul><ul><ul><li>Aromat </li></ul></ul><ul><ul><li>GE-Fanuc </li></ul></ul><ul><ul><li>IDEC </li></ul></ul><ul><ul><li>Keyence </li></ul></ul><ul><ul><ul><li>Mitsubishi </li></ul></ul></ul><ul><ul><ul><li>Modicon </li></ul></ul></ul><ul><ul><ul><li>Omron </li></ul></ul></ul><ul><ul><ul><li>Automation Direct </li></ul></ul></ul><ul><ul><ul><li>Siemens </li></ul></ul></ul><ul><ul><ul><li>Toshiba </li></ul></ul></ul>
  36. 38. PLC Manufacturers Websites <ul><li>Aromat </li></ul><ul><ul><li>http://www. aromat .com </li></ul></ul><ul><li>Keyence </li></ul><ul><ul><li>http://www. keyence .com/ plc /start. htm </li></ul></ul><ul><li>Toshiba </li></ul><ul><ul><li>http://www. toshiba plc /index.html </li></ul></ul>
  37. 39. Some Interesting PLC Websites <ul><li> </li></ul><ul><li> </li></ul><ul><li> ? </li></ul>
  38. 40. Reference <ul><li>Programmable Logic Controllers by Frank D Petruzella, McGraw – Hill Books Companey, 1989. </li></ul>
  39. 42. Thank You