1. Copyright © 2002 Delmar Thomson Learning Chapter 3 Programming a Programmable Controller

2. Copyright © 2002 Delmar Thomson Learning Objectives  Describe the available options for programming a PLC.  Explain what online is in comparison to offline.  List the advantages of software programming with a personal computer over a handheld programming terminal.

3. Copyright © 2002 Delmar Thomson Learning Objectives (cont’d.)  Explain the differences when interfacing a notebook personal computer to a PLC.  Discuss open or soft PLC programming.  Provide an overview of the IEC 1131-3 standard.

4. Copyright © 2002 Delmar Thomson Learning PLC Run Mode  The PLC can do nothing without someone developing a program and loading it into the PLC processor’s memory.  Once the program has been loaded into PLC memory the processor is put into run mode.  While in run mode, the processor is solving the ladder program.

5. Copyright © 2002 Delmar Thomson Learning PLC Run Mode (cont’d.)  While in run mode, the processor reads field device input signals and stores them in memory.  There is one memory location for each input screw terminal’s on or off state.  Field device status information is stored in the input status table.

6. Copyright © 2002 Delmar Thomson Learning PLC Programming  Oldest programming method is the handheld programmer.  Most popular programming method is IBM-compatible personal computer using either DOS or Windows software.  Higher-end PLCs can only be programmed using software.

7. Copyright © 2002 Delmar Thomson Learning Allen-Bradley SLC 500 Programming Options Image courtesy of Allen-Bradley, a Rockwell Automation business

8. Copyright © 2002 Delmar Thomson Learning Allen-Bradley SLC 500 Handheld Terminal (HHT) Image courtesy of Allen-Bradley, a Rockwell Automation business

9. Copyright © 2002 Delmar Thomson Learning Handheld Programmer and SLC 500 Modular Processors  Handheld used only on fixed SLC 500, 5/01 and 5/02 processors.  5/03, 5/04 and 5/05 modular processors allow software programming only.  MicroLogix 1000 PLC has own handheld programmer.

10. Copyright © 2002 Delmar Thomson Learning Smart Handheld Programming Terminal Advantages  Compact size.  Easy to use and learn, no software required.  Low cost; cheaper than notebook computer.  Easy to transport a program to the field.  Easy to transfer PLC program to HHT for editing or troubleshooting.

11. Copyright © 2002 Delmar Thomson Learning Smart Handheld Programming Terminal Disadvantages  Holds one program at a time.  Newer more complex processors do not support.  Limited capability to display ladder rungs.  Documentation not displayed.  Many keystrokes needed to program or edit ladder program.  Dead battery means program lost.

12. Copyright © 2002 Delmar Thomson Learning Software Programming Using PC Advantages  Newer software Windows based.  View or monitor multiple ladder rungs.  Documentation displayed.  Easy to scroll through rungs for troubleshooting.

13. Copyright © 2002 Delmar Thomson Learning Software Programming Using PC Advantages (cont’d.)  Programs stored on computer’s hard drive.  Programs transferred to floppy or CDROM.  Easy editing and programming, drag and drop, cut and paste, etc.

14. Copyright © 2002 Delmar Thomson Learning Software Programming Disadvantages  Maintenance personnel must learn Windows programming software.  Notebook computers are expensive.  Interface cards are expensive.  Personal computers not designed for factory use.  Frequent software upgrades.

15. Copyright © 2002 Delmar Thomson Learning Allen Bradley 1747-PIC Interface  1747-PIC communication box used to communicate from a PC’s serial port to a SLC 500 family data highway 485 PLC.  Connects to any PC with a serial port.  Communicates with fixed SLC 500, and 5/01, 5/02, and 5/03 modular processors.

16. Copyright © 2002 Delmar Thomson Learning AB 1747-PIC Interface Converter Interface Image courtesy of Allen-Bradley, a Rockwell Automation business

17. Copyright © 2002 Delmar Thomson Learning Connecting a GE RS-422/RS-485 to a RS-232 to a PC Image courtesy of GE Fanuc Automation

18. Copyright © 2002 Delmar Thomson Learning Connecting a GE RS-422/RS-485 to a RS-232 to a PC (cont’d.)  Easy connection between personal computer and Series 90-30 or 90-70 PLC.  Connects to computer serial port.  Connects up to 50 feet away.

19. Copyright © 2002 Delmar Thomson Learning Desk Top or Industrial Computer Interface to PLC  Allen Bradley 1784-KTX interface card.  PC ISA expansion slot card.  Connects to data highway plus or data highway 485 processors.  Set up RSLinx software drivers to communicate.

20. Copyright © 2002 Delmar Thomson Learning Allen-Bradley’s 1784-KTX Interface Card Image courtesy of Allen-Bradley, a Rockwell Automation business

21. Copyright © 2002 Delmar Thomson Learning 1784-KTX Card and Network Interface  Easy network connectivity between personal computer and up to 64 data highway plus PLC 5 or SLC 5/04 processors (nodes) on DH+ network.  Up to 32 data highway-485 SLC 500 family processors on network.

22. Copyright © 2002 Delmar Thomson Learning Node Addresses  Each device on the network will require a unique identifier called a node or station address.  Data highway plus network will support up to 64 nodes, using octal addresses.  Data highway-485 network will support up to 32 nodes, using decimal addresses.

23. Copyright © 2002 Delmar Thomson Learning Communicating to Multiple SLC 500s Image courtesy of Allen-Bradley, a Rockwell Automation business

24. Copyright © 2002 Delmar Thomson Learning Notebook PC Interface to PLC  Direct serial connection  Hardware interface device such as 1747-PIC  PCMCIA card

25. Copyright © 2002 Delmar Thomson Learning PCMCIA Interface Card  Notebook PCs do not have expansion slots for installation of KTX card.  PCMCIA card is a credit-card sized plug-in interface card.  Allen-Bradley’s PCMCIA card is called the 1784 PCMK card.  1784 PCMK card serves as an interface between a PLC and a PC used as a programming terminal.

26. Copyright © 2002 Delmar Thomson Learning 1784 PCMK Card Installation  Interface between notebook PC and either DH+ or DH-485.  Interface PLC 5 or SLC 500 family processors.  Insert card into notebook computer PCMCIA slot.

27. Copyright © 2002 Delmar Thomson Learning PCMK Card Insertion into a PC’s PCMCIA Slot Image courtesy of Allen-Bradley, a Rockwell Automation business

28. Copyright © 2002 Delmar Thomson Learning Interface Cable Attachment to PCMK Card Image courtesy of Allen-Bradley, a Rockwell Automation business

29. Copyright © 2002 Delmar Thomson Learning Interface Cable Attachment to PCMK Card (cont’d.)  One cable to communicate to SLC 500 DH-485 processors  One cable to communicate to SLC 5/04, DH+processor  Same DH+ cable will communicate to PLC 5 processors

30. Copyright © 2002 Delmar Thomson Learning Interface Cable from PCMK Card to PLC Processors Image courtesy of Allen-Bradley, a Rockwell Automation business

31. Copyright © 2002 Delmar Thomson Learning Industrial Computers  Notebook and desktop personal computers were not designed for continuous use in the manufacturing environment.

32. Copyright © 2002 Delmar Thomson Learning Industrial Computers Are Designed to Withstand:  Dirt.  Shock.  Vibration.  High temperatures.  Wash downs.

33. Copyright © 2002 Delmar Thomson Learning Industrial Computer Features  Shock-mounted hard drives  Air filters with air intake fans  Hazardous environment rating  NEMA 12, 4, and 4X ratings  Integrated mouse on front panel  Air-conditioned enclosure not required  Modular for easy repair

34. Copyright © 2002 Delmar Thomson Learning Two Styles of Industrial Computers  Panel-Mount  Computer and monitor built into one integrated unit  Rack-Mount  Computer either separate component mounted in standard 19-inch rack or embedded inside enclosure  Separate monitor or touch screen display

35. Copyright © 2002 Delmar Thomson Learning Rockwell Automation’s RAC 6181 Computer Connections Image courtesy of Allen-Bradley, a Rockwell Automation business

36. Copyright © 2002 Delmar Thomson Learning Connecting Industrial Mouse and Keyboard to the RAC 6181 Image courtesy of Allen-Bradley, a Rockwell Automation business

37. Copyright © 2002 Delmar Thomson Learning What Is the IEC 1131-3?  Standardize PLC programming  A program developed on one system could be used on other PLC platforms with minimum modification.  Programming languages, Part 3 of the 1131-3 standard, has attracted the most attention internationally.

38. Copyright © 2002 Delmar Thomson Learning IEC 1131-3 Programming Standard  Defines a consistent set of set of programming languages for PLCs:  Ladder diagram  Function block diagram  Instruction list  Structured text  Sequential function block

39. Copyright © 2002 Delmar Thomson Learning Sequential Function Chart  Similar to flowchart programming.  Consists of steps and transitions.  Each step is represented by a box that contains one or more major actions.  When actions in the box are satisfied, the box is exited.  Transition step must be true before next step.

40. Copyright © 2002 Delmar Thomson Learning Sequential Function Chart (cont’d.)

41. Copyright © 2002 Delmar Thomson Learning Sequential Function Chart OR Logic

42. Copyright © 2002 Delmar Thomson Learning Sequential Function Chart Illustrating a Simultaneous Branch