Programmable Logic Controllers - Dogwood …

1 Programmable LogicControllers:An Emphasis on Design and ApplicationSecond EditionKelvin T. EricksonMissouri University of Science and TechnologyDogwoodValleyPress,LLCC opyright 2011 Dogwood Valley Press, LLC. All rights portion of this book may be reproduced, stored in a retrieval system, or transmitted inany form or by any means, including electronic, mechanical, photocopying, scanning,recording or otherwise, except as permitted under the 1976 United States Copyright Act,without explicit.

2 Prior written permission of the publisher except for brief passagesexcerpted for review and critical book was set in Times New Roman and printed on acid-free in the United States of AmericaISBN 978-0-9766259-2-6 Dogwood Valley Press, LLC1604 Lincoln LaneRolla, MO 654011-573-426-3507 to Fran, Esther, David and AmandaCONTENTSP refaceviiChapter 1 Introduction to Control in System of the Versus Other PLC Summary20 References20 Chapter 2 Basic Ladder Logic Ladder Ladder Logic Logic Processor with NC Contacts and Summary66 References66 Problems67 Chapter 3 Memory Organization and 61131-3 Memory Unity ControlLogix/CompactLogix PLC-5 and SLC-500/MicroLogix S7 Summary144 References144 Problems147 Chapter 4 Input/Output Modules and Summary200

3 References200 Problems203 Chapter 5 Timers and Timers and Timers and ControlLogix Timers and PLC-5/SLC-500 Timers and S7 Timers and Timers and Timer and Counter Summary279 References280 Problems281 Chapter 6 Sequential Function Chart in Ladder Reset Questions in the Sequential Design and Single-Step Sequential When PLC Has No Set/Reset Summary374 References379 Problems380 Chapter 7 Comparison and of Physical Comparison and Comparison and ControlLogix Comparison and PLC-5/SLC-500 Comparison and S7 Comparison and Comparison and Summary520 References520 Problems522 Chapter 8 Other Ladder Logic IEC Function Modicon Function ControlLogix Function PLC-5/SLC-500/MicroLogix Function Siemens S7 Function GE Function Summary678 References680 Problems682 Chapter 9 Other Function Chart Register-Based Function Summary769 References769 Problems771 Chapter 10 PID Control controller Control PID Function

4 Summary864 References864 Problems866 Chapter 11 Function Block 61131-3 Function Block Function Block Function Block S7 Function Block PACS ystems Function Block Summary933 References933 Problems935 Chapter 12 Structured 61131-3 Structured Structured Structured Structured S7 Structured Control PACS ystems Structured Summary971 References971 Problems972 Chapter 13 Instruction 61131-3 Instruction Instruction S7 Statement List Instruction Summary991 References991 Problems992 Chapter 14 Sequential Function 61131-3 Sequential Function Sequential Function Sequential Function Sequential Function S7 Sequential Function Summary1082 References1082 Problems1083 Chapter Troubleshooting I/O Status for Fault Summary1109 References1109 Chapter 16 Sensors and Summary1184 References1184 Appendix - Thermocouple Conversion Polynomial Coefficients1186 Problems1192 Chapter 17 Communication (DP, PA, PROFInet)

5 Proprietary Proprietary Logic Communication Summary1276 References1276 Chapter 18 Human-Machine Panel HMI HMI Summary1305 References1305 Chapter 19 Control System Automation Network Processor Security1312 Contents Summary1325 References1325 Chapter 20 Selecting a Summary1337 References1338 Chapter 21 Control Control Design Control Requirements Summary1428 References1428 Problems1430 Chapter 22 Example Handling Chemical Summary1444 References1444 Appendix ANumber Systems and Conversions1445 Appendix BElectrical Diagram Symbols1451 Appendix CPiping and Instrumentation Diagram (P&ID) Symbols1454 Glossary1457 Index1473viContentsPREFACEThe field of automatic control has been undergoing a transformation over the pasttwenty years.

6 Twenty years ago, the engineering undergraduate had a course in feedbackcontrol theory and those interested in control engineering secured a position in theaerospace or chemical industries. Due to various factors, the number of control engineeringpositions in the aerospace industry has been declining, but the number of controlengineering positions in manufacturing has been dramatically increasing to the point thatthe majority of control engineering positions is now in manufacturing and involves book presents the subject of programming industrial Controllers , calledprogrammable Logic Controllers (PLCs)

7 With an emphasis on the design of the texts teach one how to program the PLC in its languages, but little, if any, attention ispaid to how does one attack the problem: Given a set of operational specifications, howdoes one develop the PLC program? This book develops the design process: the tasksinvolved, breaking the program into manageable pieces, standard code for the various parts,and handling the sequential parts of the problem. The emphasis is toward those who will beprogramming of its popularity (now and in the future), ladder Logic is the language that isused for the majority of the text.

8 The industry trend is toward using the IEC 61131-3(formerly IEC 1131-3) standard, and so it is the primary language. However, IEC 61131-3is only a voluntary standard and individual manufacturers have some freedom in theimplementation. Therefore, the Allen-Bradley ControlLogix, Modicon, Siemens S7, andGE implementations of the 61131-3 standard are covered. Because of their large installedbase, the Allen-Bradley PLC-5/SLC-500 PLC languages are also to the limitations of ladder Logic , the IEC 61131-3 standard defines four otherlanguages: function block diagram, structured text, instruction list, and sequential functionchart.

9 These four languages will become more popular in the future. Therefore, this text alsocovers these a typical manufacturing plant may contain discrete, continuous, and batchprocesses, all of these applications are treated in this text, although the emphasis is ondiscrete and continuous processes. The emphasis is on a methodology that can be applied toany automation project, regardless of the , the book contains example problems demonstrating good design addition, these problems are solved with each PLC covered in the book.

10 The textculminates in two full-length case studies where the application of the design techniques toa large problem is book takes a practical approach to the design of PLC control systems. Somemathematical theory is used to backup the presentation on PID Controllers . However, thetheory is not detailed and can be for Chapters 1 and 13, every chapter begins with a scenario that reflects theexperience of the author and his colleagues in the challenging world of factory scenarios present a small problem and the solution and are intended to illustratetroubleshooting main objectives of this text are to teach.