Classic 1785 PLC5 User Manual - Rockwell Automation

1 UserManualClassic 1785 PLC 5 ProgrammableControllers(1785 LT, LT2, LT3, LT4)Allen BradleyBecause of the variety of uses for the products described in thispublication, those responsible for the application and use of this controlequipment must satisfy themselves that all necessary steps have beentaken to assure that each application and use meets all performance andsafety requirements, including any applicable laws, regulations, codes,and illustrations, charts, sample programs, and layout examples shown inthis guide are intended solely for purposes of example. Since there aremany variables and requirements associated with any particularinstallation, Allen-Bradley does not assume responsibility or liability (to include intellectual property liability) for actual use based on theexamples shown in this publication , Safety Guidelines for the Application,Installation, and Maintenance of Solid State Control (available from yourlocal Allen-Bradley office)

2 , describes some important differences betweensolid-state equipment and electromechanical devices that should be takeninto consideration when applying products such as those described inthis of the contents of this copyrighted publication, in wholeor in part, without written permission of Allen-Bradley Company, Inc.,is this Manual we use notes to make you aware ofsafety considerations:ATTENTION: Identifies information about practices orcircumstances that can lead to personal injury or death,property damage, or economic statements help you to: identify a hazard avoid the hazard recognize the consequencesImportant: Identifies information that is critical for successful applicationand understanding of the User InformationSummary of ChangesiSummary of ChangesThis Manual has been revised to cover only Classic PLC-5 programmablecontrollers.

3 PLC-5/10, -5/12, -5/15, and -5 has also been revised to include the accompanying design worksheetsthat were formerly available as a separate publication: Thisseparate publication is no longer available; see Appendix B for information about Enhanced and Ethernet PLC-5 processors, see theEnhanced and Ethernet PLC-5 programmable Controllers User Manual ,publication of Changes i.. Classic plc 5 programmable Controllers iii.. Purpose of this Manual iii.. Manual Organization iv.. How to Use this Manual iv.. Understanding Your System 1 1.. Using this Chapter 1 1.. Understanding the Terms Used in this Chapter 1 1.

4 Designing Systems 1 2.. Preparing Your Functional Specification 1 3.. Introducing Classic PLC 5 Processor Modules 1 5.. Using the Classic PLC 5 Processor as a Remote I/O Scanner 1 8.. Using the Classic PLC 5 Processor as a Remote I/O Adapter 1 9.. Choosing hardware 2 1.. Chapter Objectives 2 1.. Selecting I/O Modules 2 1.. Selecting I/O Adapter Modules 2 4.. Selecting I/O Chassis 2 6.. Selecting an Operator Interface 2 6.. Choosing a Classic PLC 5 Processor for Your Application 2 9.. Selecting Power Supplies 2 9.. Selecting Memory Modules 2 13.. Selecting a Replacement Battery 2 13.. Selecting Complementary I/O 2 13.

5 Selecting a PLC 5 Processor Backup System 2 14.. Selecting Link Terminators 2 15.. Connecting a Programming Terminal to a Processor Module 2 15.. Choosing Cables 2 15.. Placing System hardware 3 1.. Chapter Objectives 3 1.. Determining the Proper Environment 3 1.. Protecting Your Processor 3 4.. Avoiding Electrostatic Damage 3 4.. Laying Out Your Cable Raceway 3 4.. Planning Cabling 3 5.. Laying Out the Backpanel Spacing 3 6.. Grounding Configuration 3 7.. Table of ContentsTable of ContentsiiAssigning Addressing Modes, Racks, and Groups 4 1.. Chapter Objectives 4 1.. Placing I/O Modules in Chassis 4 1.

6 Understanding the Terms Used in this Chapter 4 2.. Choosing the Addressing Mode 4 3.. Assigning Racks 4 9.. Addressing Complementary I/O 4 12.. Choosing Communication 5 1.. Chapter Objectives 5 1.. Identifying Classic PLC 5 Processor Channels/Connectors 5 1.. Configuring Communication for Your Processor 5 3.. Configuring a DH+ Link 5 3.. Connecting a DH+ Link to Data Highway 5 10.. Choosing Programming Terminal Connection 5 10.. Planning Your System Programs 6 1.. Chapter Objectives 6 1.. Planning Application Programs 6 1.. Using SFCs with PLC 5 Processors 6 1.. Preparing the Programs for Your Application 6 3.

7 Addressing Data Table Files 6 7.. Using the Processor Status File 6 9.. Selecting Interrupt Routines 7 1.. Chapter Objectives 7 1.. Using Programming Features 7 1.. Writing a Fault Routine 7 3.. Understanding Processor Detected Major Faults 7 11.. Transferring Discrete and Block Transfer Data 8 1.. Chapter Objectives 8 1.. Transferring Data Using Adapter Mode 8 1.. Programming Discrete Transfer in Adapter Mode 8 4.. Programming Block Transfer in Adapter Mode 8 7.. Transferring Data Using Scanner Mode 8 16.. Programming Discrete Transfer in Scanner Mode 8 16.. Programming Block Transfer in Scanner Mode 8 17.

8 Programming Considerations 8 21.. Table of ContentsiiiCalculating Program Timing 9 1.. Chapter Objectives 9 1.. Introduction to Classic PLC 5 Processor Scanning 9 1.. I/O Scanning Discrete and Block Transfer 9 5.. Instruction Timing and Memory Requirements 9 7.. Program Constants 9 13.. Direct and Indirect Elements 9 13.. Maximizing System Performance 10 1.. Chapter Objectives 10 1.. Components of Throughput 10 1.. Input and Output Modules Delay 10 1.. I/O Backplane Transfer 10 2.. Remote I/O Scan Time 10 2.. Processor Time 10 6.. Calculating Throughput 10 6.. Selecting Switch Settings A 1.. Chassis Backplane with Classic PLC 5 Processor A 1.

9 Chassis Backplane with Adapter Module A 2.. Chassis Configuration Plug for Power Supply A 3.. Remote I/O Adapter Module 1771 ASB Series C without Complementary I/O A 4.. Remote I/O Adapter Module 1771 ASB Series C with Complementary I/O A 6.. SW1 A 7.. Adapter Mode Processors SW2 in a PLC 5 or Scanner Module A 8.. Adapter Mode Processors SW2 in a PLC 2/20, 2/30, or Sub I/O Scanner Module System A 9.. Adapter Mode Processors SW2 in a PLC 3 or PLC 5/250 System with 8 Word Groups A 10.. Adapter Mode Processors SW2 in a PLC 3 or PLC 5/250 System with 4 Word Groups A 11.. SW3 A 12.. Design Worksheets B 1.

10 Conventions Used in These Worksheets B 1.. Prepare a Functional Specification B 2.. Determine Control Strategy B 4.. Identify Chassis Locations B 6.. Select Module Types and List I/O Points B 7.. Total I/O Module Requirements B 9.. Assign I/O Modules to Chassis and Assign Addresses B 10.. Select Adapter Modules B 12.. Place System hardware B 14.. Table of ContentsivConfigure Switch Settings B 15.. Determine Communication Requirements B 17.. Select a Classic PLC 5 Processor B 21.. Select Power Supplies B 23.. Choose a Programming Terminal B 24.. Select Programming Terminal Configuration B 25.. Select Operator Interface B 26.