Programmable Logic Controllers, 4th Edition

now In Four-color, This Outstanding Text For The First Course In Programmable Logic Controllers (plcs) Focuses On How Plcs Work And Gives Students Practical Information About Installing, Programming, And Maintaining Plc Systems. It's Not Intended To Replace Manufacturer's Or User's Manuals, But Rather Complements And Expands On The Information Contained In These Materials. All Topics Are Covered In Small Segments. Students Systematically Carry Out A Wide Range Of Generic Programming Exercises And Assignments. All Of The Information About Plcs Has Been Updated. Cover......Page 2 Title Page......Page 4 Copyright......Page 5 Contents......Page 6 Preface......Page 10 Acknowledgments......Page 13 About the Author......Page 14 Walkthrough.......Page 15 1 Programmable Logic Controllers (PLCs) An Overview......Page 19 1.1 Programmable Logic Controllers......Page 20 1.2 Parts of a PLC......Page 22 1.3 Principles of Operation......Page 26 1.5 PLCs versus Computers......Page 29 1.6 PLC Size and Application......Page 30 Problems......Page 33 2 PLC Hardware Components......Page 35 2.1 The I/O Section......Page 36 2.2 Discrete I/O Modules......Page 40 2.3 Analog I/O Modules......Page 45 2.4 Special I/O Modules......Page 47 Typical Discrete I/O Module Specications......Page 50 2.6 The Central Processing Unit (CPU)......Page 51 2.7 Memory Design......Page 53 2.8 Memory Types......Page 54 2.9 Programming Terminal Devices......Page 55 2.11 Human Machine Interfaces (HMIs)......Page 56 Review Questions.......Page 58 Problems......Page 60 3 Number Systems and Codes......Page 61 3.2 Binary System......Page 62 3.3 Negative Numbers......Page 64 3.4 Octal System......Page 65 3.6 Binary Coded Decimal (BCD) System.......Page 66 3.7 Gray Code......Page 68 3.10 Binary Arithmetic......Page 69 Review Questions.......Page 73 Problems......Page 74 4 Fundamentals of Logic......Page 75 The AND Function......Page 76 The OR Function......Page 77 The NOT Function......Page 78 4.3 Boolean Algebra......Page 79 4.5 Producing the Boolean Equation for a Given Logic Gate Circuit......Page 81 4.6 Hardwired Logic versus Programmed Logic......Page 82 4.7 Programming Word Level Logic Instructions......Page 85 Problems......Page 87 5 Basics of PLC Programming......Page 89 Data Files......Page 90 5.2 Program Scan......Page 94 5.3 PLC Programming Languages......Page 97 5.4 Relay-Type Instructions......Page 99 5.5 Instruction Addressing......Page 102 5.6 Branch Instructions......Page 103 5.7 Internal Relay Instructions......Page 105 5.8 Programming Examine If Closed and Examine If Open Instructions......Page 106 5.9 Entering the Ladder Diagram......Page 107 5.10 Modes of Operation......Page 109 Review Questions......Page 110 Problems......Page 111 6 Developing Fundamental PLC Wiring Diagrams and Ladder Logic Programs......Page 113 6.1 Electromagnetic Control Relays......Page 114 6.2 Contactors......Page 115 6.3 Motor Starters......Page 116 6.4 Manually Operated Switches......Page 117 6.5 Mechanically Operated Switches......Page 118 Proximity Sensor......Page 119 Light Sensors......Page 122 Strain/Weight Sensors......Page 124 Flow Measurement......Page 125 6.7 Output Control Devices......Page 126 6.8 Seal-In Circuits......Page 128 6.9 Latching Relays......Page 129 6.10 Converting Relay Schematics into PLC Ladder Programs......Page 134 6.11 Writing a Ladder Logic Program Directly from a Narrative Description......Page 137 Review Questions......Page 140 Problems......Page 141 7 Programming Timers......Page 143 7.1 Mechanical Timing Relays......Page 144 7.2 Timer Instructions......Page 146 7.3 On-Delay Timer Instruction......Page 147 7.4 Off-Delay Timer Instruction......Page 151 7.5 Retentive Timer......Page 154 7.6 Cascading Timers......Page 158 Problems......Page 162 8 Programming Counters......Page 167 8.1 Counter Instructions......Page 168 8.2 Up-Counter......Page 170 8.3 Down-Counter......Page 177 8.4 Cascading Counters......Page 180 8.5 Incremental Encoder-Counter Applications......Page 183 8.6 Combining Counter and Timer Functions......Page 184 Problems......Page 189 9 Program Control Instructions......Page 194 9.1 Master Control Reset Instruction......Page 195 9.2 Jump Instruction......Page 198 9.3 Subroutine Functions......Page 199 9.4 Immediate Input and Immediate Output Instructions......Page 202 9.5 Forcing External I/O Addresses......Page 205 9.6 Safety Circuitry......Page 208 9.7 Selectable Timed Interrupt......Page 211 9.9 Temporary End Instruction......Page 212 9.10 Suspend Instruction......Page 213 Problems......Page 214 10 Data Manipulation Instructions......Page 218 10.2 Data Transfer Operations......Page 219 10.3 Data Compare Instructions......Page 227 10.4 Data Manipulation Programs......Page 231 10.5 Numerical Data I/O Interfaces......Page 234 10.6 Closed-Loop Control......Page 236 Review Questions......Page 240 Problems......Page 241 11 Math Instructions......Page 244 11.2 Addition Instruction......Page 245 11.3 Subtraction Instruction......Page 247 11.4 Multiplication Instruction......Page 248 11.5 Division Instruction......Page 249 11.6 Other Word-Level Math Instructions......Page 251 11.7 File Arithmetic Operations......Page 253 Review Questions......Page 255 Problems......Page 256 12 Sequencer and Shift Register Instructions......Page 260 12.1 Mechanical Sequencers......Page 261 12.2 Sequencer Instructions......Page 263 12.3 Sequencer Programs......Page 266 12.4 Bit Shift Registers......Page 272 12.5 Word Shift Operations......Page 278 Problems......Page 282 13PLC Installation Practices,Editing, and Troubleshooting......Page 286 13.1 PLC Enclosures......Page 287 13.2 Electrical Noise......Page 289 13.4 Grounding......Page 290 13.5 Voltage Variations and Surges......Page 292 13.6 Program Editing and Commissioning......Page 293 13.7 Programming and Monitoring......Page 294 13.8 Preventive Maintenance......Page 296 Input Malfunctions......Page 297 Ladder Logic Program......Page 299 13.10 PLC Programming Software......Page 304 Problems......Page 306 14 Process Control, Network Systems, and SCADA......Page 309 14.1 Types of Processes......Page 310 14.2 Structure of Control Systems......Page 312 14.3 On/Off Control......Page 314 14.4 PID Control......Page 315 14.5 Motion Control......Page 319 14.6 Data Communications......Page 321 DeviceNet......Page 326 ControlNet......Page 328 Modbus......Page 329 Fieldbus......Page 330 14.7 Supervisory Control and Data Acquisition (SCADA)......Page 331 Review Questions......Page 333 Problems......Page 334 15 ControlLogix Controllers......Page 335 Conguration......Page 336 Project......Page 337 Programs......Page 338 Tags......Page 339 Structures......Page 342 Creating Tags......Page 343 Array......Page 344 Review Questions......Page 346 Program Scan......Page 347 Creating Ladder Logic......Page 348 Tag-Based Addressing......Page 349 Adding Ladder Logic to the Main Routine ......Page 350 Latch and Unlatch Instructions......Page 352 One-Shot Instruction......Page 353 Problems......Page 354 Timer Prede. ned Structure......Page 356 On-Delay Timer (TON)......Page 357 Off-Delay Timer (TOF)......Page 360 Retentive Timer On (RTO)......Page 362 Problems......Page 364 Counters......Page 365 Count-Up (CTU) Counter......Page 366 Count-Down (CTD) Counter......Page 368 Problems......Page 370 Math Instructions......Page 371 Comparison Instructions......Page 373 Move Instructions......Page 375 Problems......Page 378 Function Block Diagram (FBD)......Page 379 FBD Programming......Page 383 Problems......Page 389 Glossary......Page 391 Index......Page 403 Cover 2 Title Page 4 Copyright 5 Contents 6 Preface 10 Acknowledgments 13 About the Author 14 Walkthrough. 15 1 Programmable Logic Controllers (PLCs) An Overview 19 1.1 Programmable Logic Controllers 20 1.2 Parts of a PLC 22 1.3 Principles of Operation 26 1.4 Modifying the Operation 29 1.5 PLCs versus Computers 29 1.6 PLC Size and Application 30 Review Questions 33 Problems 33 2 PLC Hardware Components 35 2.1 The I/O Section 36 2.2 Discrete I/O Modules 40 2.3 Analog I/O Modules 45 2.4 Special I/O Modules 47 2.5 I/O Speci. cations 50 Typical Discrete I/O Module Specications 50 Typical Analog I/O Module Specications 51 2.6 The Central Processing Unit (CPU) 51 2.7 Memory Design 53 2.8 Memory Types 54 2.9 Programming Terminal Devices 55 2.10 Recording and Retrieving Data 56 2.11 Human Machine Interfaces (HMIs) 56 Review Questions. 58 Problems 60 3 Number Systems and Codes 61 3.1 Decimal System 62 3.2 Binary System 62 3.3 Negative Numbers 64 3.4 Octal System 65 3.5 Hexadecimal System 66 3.6 Binary Coded Decimal (BCD) System. 66 3.7 Gray Code 68 3.8 ASCII Code 69 3.9 Parity Bit 69 3.10 Binary Arithmetic 69 Review Questions. 73 Problems 74 4 Fundamentals of Logic 75 4.1 The Binary Concept 76 4.2 AND, OR, and NOT Functions 76 The AND Function 76 The OR Function 77 The NOT Function 78 The Exclusive-OR (XOR) Function 79 4.3 Boolean Algebra 79 4.4 Developing Logic Gate Circuits from Boolean Expressions 81 4.5 Producing the Boolean Equation for a Given Logic Gate Circuit 81 4.6 Hardwired Logic versus Programmed Logic 82 4.7 Programming Word Level Logic Instructions 85 Review Questions. 87 Problems 87 5 Basics of PLC Programming 89 5.1 Processor Memory Organization 90 Program Files 90 Data Files 90 5.2 Program Scan 94 5.3 PLC Programming Languages 97 5.4 Relay-Type Instructions 99 5.5 Instruction Addressing 102 5.6 Branch Instructions 103 5.7 Internal Relay Instructions 105 5.8 Programming Examine If Closed and Examine If Open Instructions 106 5.9 Entering the Ladder Diagram 107 5.10 Modes of Operation 109 Review Questions 110 Problems 111 6 Developing Fundamental PLC Wiring Diagrams and Ladder Logic Programs 113 6.1 Electromagnetic Control Relays 114 6.2 Contactors 115 6.3 Motor Starters 116 6.4 Manually Operated Switches 117 6.5 Mechanically Operated Switches 118 6.6 Sensors 119 Proximity Sensor 119 Magnetic Reed Switch 122 Light Sensors 122 Ultrasonic Sensors 124 Strain/Weight Sensors 124 Temperature Sensors 125 Flow Measurement 125 Velocity and Position Sensors 126 6.7 Output Control Devices 126 6.8 Seal-In Circuits 128 6.9 Latching Relays 129 6.10 Converting Relay Schematics into PLC Ladder Programs 134 6.11 Writing a Ladder Logic Program Directly from a Narrative Description 137 Review Questions 140 Problems 141 7 Programming Timers 143 7.1 Mechanical Timing Relays 144 7.2 Timer Instructions 146 7.3 On-Delay Timer Instruction 147 7.4 Off-Delay Timer Instruction 151 7.5 Retentive Timer 154 7.6 Cascading Timers 158 Review Questions 162 Problems 162 8 Programming Counters 167 8.1 Counter Instructions 168 8.2 Up-Counter 170 8.3 Down-Counter 177 8.4 Cascading Counters 180 8.5 Incremental Encoder-Counter Applications 183 8.6 Combining Counter and Timer Functions 184 Review Questions 189 Problems 189 9 Program Control Instructions 194 9.1 Master Control Reset Instruction 195 9.2 Jump Instruction 198 9.3 Subroutine Functions 199 9.4 Immediate Input and Immediate Output Instructions 202 9.5 Forcing External I/O Addresses 205 9.6 Safety Circuitry 208 9.7 Selectable Timed Interrupt 211 9.8 Fault Routine 212 9.9 Temporary End Instruction 212 9.10 Suspend Instruction 213 Review Questions 214 Problems 214 10 Data Manipulation Instructions 218 10.1 Data Manipulation 219 10.2 Data Transfer Operations 219 10.3 Data Compare Instructions 227 10.4 Data Manipulation Programs 231 10.5 Numerical Data I/O Interfaces 234 10.6 Closed-Loop Control 236 Review Questions 240 Problems 241 11 Math Instructions 244 11.1 Math Instructions 245 11.2 Addition Instruction 245 11.3 Subtraction Instruction 247 11.4 Multiplication Instruction 248 11.5 Division Instruction 249 11.6 Other Word-Level Math Instructions 251 11.7 File Arithmetic Operations 253 Review Questions 255 Problems 256 12 Sequencer and Shift Register Instructions 260 12.1 Mechanical Sequencers 261 12.2 Sequencer Instructions 263 12.3 Sequencer Programs 266 12.4 Bit Shift Registers 272 12.5 Word Shift Operations 278 Review Questions 282 Problems 282 13PLC Installation Practices,Editing, and Troubleshooting 286 13.1 PLC Enclosures 287 13.2 Electrical Noise 289 13.3 Leaky Inputs and Outputs 290 13.4 Grounding 290 13.5 Voltage Variations and Surges 292 13.6 Program Editing and Commissioning 293 13.7 Programming and Monitoring 294 13.8 Preventive Maintenance 296 13.9 Troubleshooting 297 Processor Module 297 Input Malfunctions 297 Output Malfunctions 299 Ladder Logic Program 299 13.10 PLC Programming Software 304 Review Questions 306 Problems 306 14 Process Control, Network Systems, and SCADA 309 14.1 Types of Processes 310 14.2 Structure of Control Systems 312 14.3 On/Off Control 314 14.4 PID Control 315 14.5 Motion Control 319 14.6 Data Communications 321 Data Highway 326 Serial Communication 326 DeviceNet 326 ControlNet 328 EtherNet/IP 329 Modbus 329 Fieldbus 330 PROFIBUS-DP 331 14.7 Supervisory Control and Data Acquisition (SCADA) 331 Review Questions 333 Problems 334 15 ControlLogix Controllers 335 Part 1 Memory and Project Organization 336 Memory Layout 336 Conguration 336 Project 337 Programs 338 Routines 339 Tags 339 Structures 342 Creating Tags 343 Monitoring and Editing Tags 344 Array 344 Review Questions 346 Part 2 Bit-Level Programming 347 Program Scan 347 Creating Ladder Logic 348 Tag-Based Addressing 349 Adding Ladder Logic to the Main Routine 350 Internal Relay Instructions 352 Latch and Unlatch Instructions 352 One-Shot Instruction 353 Review Questions 354 Problems 354 Part 3 Programming Timers 356 Timer Prede. ned Structure 356 On-Delay Timer (TON) 357 Off-Delay Timer (TOF) 360 Retentive Timer On (RTO) 362 Review Questions 364 Problems 364 Part 4 Programming Counters 365 Counters 365 Count-Up (CTU) Counter 366 Count-Down (CTD) Counter 368 Review Questions 370 Problems 370 Part 5 Math, Comparison, and Move Instructions 371 Math Instructions 371 Comparison Instructions 373 Move Instructions 375 Review Questions 378 Problems 378 Part 6 Function BlockProgramming 379 Function Block Diagram (FBD) 379 FBD Programming 383 Review Questions 389 Problems 389 Glossary 391 Index 403 This fourth edition of "Programmable Logic Controllers" continues to provide an up-to-date introduction to all aspects of PLC programming, installation, and maintaining procedures. No previous knowledge of PLC systems or programming is assumed. As one reviewer of this edition put it "I honestly believe that someone with little or no background to PLC systems could take this book and teach themselves PLCs"