1. Copyright © 2002 Delmar Thomson Learning Chapter 13 Understanding Relay Instructions and the Programmable Controller Input Modules

2. Copyright © 2002 Delmar Thomson Learning Objectives  Explain proper programming of normal closed and normally open PLC input signals.  Describe hardware relay operation and its correlation to proper PLC interface and programming.  Convert a conventional start-stop schematic to a PLC ladder rung diagram.

3. Copyright © 2002 Delmar Thomson Learning Objectives (cont’d.)  Explain why PLC ladder logic for motor starter interface has an additional contact in comparison to a conventional schematic.  Hook up a start-stop station to a PLC input module.  Hook up and develop a PLC program to correctly control a motor starter.

4. Copyright © 2002 Delmar Thomson Learning Typical Hard-Wired Start-Stop Latching Circuit

5. Copyright © 2002 Delmar Thomson Learning Incorrect Conversion of Conventional Start-Stop Schematic to PLC Control

6. Copyright © 2002 Delmar Thomson Learning Normally Open Push Button and Non-Energized Relay

7. Copyright © 2002 Delmar Thomson Learning Normally Open Push Button Energizing Relay Coil and Pilot Light B

8. Copyright © 2002 Delmar Thomson Learning Normally Closed Push Button Energizing Relay Coil and Pilot Light B

9. Copyright © 2002 Delmar Thomson Learning Normally Closed Stop Push Button Depressed

10. Copyright © 2002 Delmar Thomson Learning Relay Status in Conjunction with Input Push Buttons

11. Copyright © 2002 Delmar Thomson Learning Input and Output Separation

12. Copyright © 2002 Delmar Thomson Learning Separated Inputs Connected to PLC Input Screw Terminals

13. Copyright © 2002 Delmar Thomson Learning Start Push-Button Status Reflected in the Input Status Table

14. Copyright © 2002 Delmar Thomson Learning Start-Stop Input Bit Status from Input Hardware in a Non-Energized State

15. Copyright © 2002 Delmar Thomson Learning Normally Open Push Button Not Activated

16. Copyright © 2002 Delmar Thomson Learning Normally Open Push Button Input Pressed

17. Copyright © 2002 Delmar Thomson Learning Normally Closed Input Push Button

18. Copyright © 2002 Delmar Thomson Learning Normally Closed Push Button Input to PLC

19. Copyright © 2002 Delmar Thomson Learning Push Button Released Output Latched through CR 1-1

20. Copyright © 2002 Delmar Thomson Learning Conventional Schematic Start-Stop Logic

21. Copyright © 2002 Delmar Thomson Learning Conventional Motor Starter Schematic Diagram

22. Copyright © 2002 Delmar Thomson Learning Conventional Motor Starter Circuit Converted for PLC System Management