IEC61131-3 Programming industrial automation systems

Contents......Page 3 1 Introduction......Page 11 1.1 Subject of the Book......Page 12 1.2.1 Goals and benefits of the standard......Page 14 Customers......Page 15 1.2.2 History and components......Page 16 1.3.1 Aims......Page 18 1.3.2 Committees and fields of activity......Page 19 Certification......Page 20 Exchange format for user programs......Page 21 2.1 Introduction to the New Standard......Page 22 Declaration of variables......Page 23 Code part of a POU......Page 24 2.1.2 Introductory example written in IL......Page 26 2.1.3 PLC assignment......Page 28 2.2 The Program Organisation Unit (POU)......Page 31 2.3 Elements of a POU......Page 33 2.3.1 Example......Page 34 2.3.2 Declaration part......Page 35 Characteristics of the POU interface......Page 36 The formal parameters and return values of a POU......Page 37 External and internal access to POU variables......Page 38 2.3.3 Code part......Page 40 2.4.1 Instances of function blocks......Page 41 What is an “instance”?......Page 42 Instance means “structure”.......Page 43 Instance means “memory”.......Page 45 Relationship between FB instances and data blocks.......Page 46 2.4.2 Re-usable and object-oriented FBs......Page 47 2.5 The Function......Page 48 2.5.1 Types of variables in functions and the function value......Page 49 2.5.2 Execution control with EN and ENO......Page 50 2.6 The Program......Page 52 2.7.1 Mutual calls of POUs......Page 53 2.7.2 Recursive calls are forbidden......Page 54 2.7.3 Calling with formal parameters......Page 56 2.7.4 Calls with input parameters omitted or in a different order......Page 58 2.7.5 FB instances as actual FB parameters......Page 59 Example of an indirect FB call.......Page 61 2.8 Summary of POU Features......Page 63 3 Variables, Data Types and Common Elements......Page 65 4 The New Programming Languages of IEC€61131-3......Page 66 5 Standardised PLC Functionality......Page 67 5.1 Standard Functions......Page 68 Overloaded functions......Page 72 Extensible functions......Page 74 5.1.1 Examples......Page 75 Type conversion functions......Page 76 Arithmetic functions......Page 77 Bitwise Boolean functions......Page 78 Selection functions......Page 79 Comparison functions......Page 80 Functions for time data types.......Page 81 Functions for enumerated data types......Page 82 5.2 Standard Function Blocks......Page 83 5.2.2 Examples......Page 84 Edge detection......Page 86 Counter......Page 88 Timer......Page 89 6.1 Structuring Projects with Configuration Elements......Page 92 6.2 Elements of a Real-World PLC Configuration......Page 93 6.3.1 Definitions......Page 95 6.3.2 The CONFIGURATION......Page 96 6.3.3 The RESOURCE......Page 97 6.3.4 The TASK with run-time program......Page 98 6.3.5 ACCESS declarations......Page 101 6.4 Configuration Example......Page 102 6.5 Communication between Configurations and POUs......Page 105 7.1 Requirements of Innovative Programming Tools......Page 108 7.2.4 Uniform user interfaces......Page 109 7.3 Decompilation (Reverse Documentation)......Page 110 7.3.3 Decompilation including graphics......Page 111 7.4.1 Cross-compilation......Page 112 The motivation for cross-compilation......Page 113 Different approaches in graphical and textual languages.......Page 114 Differences in languages affect cross-compilation.......Page 115 Cross-compilation IL / ST.......Page 116 Full cross-compilation only with additional information.......Page 117 Quality criteria for cross-compilation.......Page 118 7.4.2 Language independence......Page 119 7.5.1 Cross-reference list......Page 120 7.5.3 Comments......Page 121 7.6 Project Manager......Page 122 7.7.1 Program transfer......Page 126 7.7.3 Remote control: Starting and stopping the PLC......Page 127 7.7.4 Variable and program status......Page 128 7.7.5 Forcing......Page 132 7.7.6 Program test......Page 133 7.8 Data Blocks and Recipes......Page 134 7.9.1 Data exchange and co-ordination of blocks in distributed systems......Page 138 7.9.2 Macro techniques in FB interconnection......Page 140 7.10 Diagnostics, Error Detection and Error Handling......Page 141 Extended error handling model (beyond IEC).......Page 142 7.12 Readiness for New Functionality......Page 144 7.12.1 Exchange of programs and data......Page 145 7.12.2 Extension with additional software packages......Page 146 8.1 Convenience and Security with Variables and Data Types......Page 148 8.2 Blocks with Extended Capabilities......Page 149 8.3 PLC Configuration with Run-Time Behaviour......Page 150 8.6 Trend towards Open PLC Programming Systems......Page 151 8.7 Conclusion......Page 153 9.1 Programming by FB Interconnection with IEC€61131......Page 154 9.2 IEC 61499 – The Programming Standard for Distributed PLC Systems......Page 155 9.2.2 Device model......Page 156 9.2.3 Resource model......Page 157 9.2.4 Application model......Page 158 9.2.5 Function block model......Page 159 Composite function blocks......Page 161 9.3 Overview of the Parts of IEC€61499......Page 163 Footnote......Page 164 10.2 Buyer's Guide for IEC€61131......Page 165 A.1 Type Conversion Functions......Page 166 A.2 Numerical Functions......Page 167 A.3 Arithmetic Functions......Page 168 A.5 Bitwise Boolean Functions......Page 170 A.6 Selection Functions for Max., Min. and Limit......Page 171 A.7 Selection Functions for Binary Selection and Multiplexers......Page 173 A.8 Comparison Functions......Page 174 A.9 Character String Functions......Page 176 A.10 Functions for Time Data Types......Page 177 A.11 Functions for Enumerated Data Types......Page 179 B.1 Bistable Elements (Flip-Flops)......Page 180 B.2 Edge Detection......Page 181 B.3 Counters......Page 182 B.4 Timers......Page 184 C.1 Example of a FUNCTION......Page 188 C.2 Example of a FUNCTION_BLOCK......Page 190 C.3 Example of a PROGRAM......Page 192 D Standard Data Types......Page 196 E Causes of Error......Page 199 F Implementation-Dependent Parameters......Page 201 G.1 Syntax Diagrams for IL......Page 205 G.2 IL Example from Syntax Diagrams......Page 213 H.1 Reserved Keywords......Page 215 H.2 Delimiters......Page 218 I Planned Amendments to the Standard......Page 223 J Glossary......Page 225 K Bibliography......Page 231 L Index......Page 234