plc.myforum.ro

ratko · Member 3 Joined: 20 Jul 2012 Posts: 524

IEC+61131-3+Programming+Industrial+Automation+Systems

Contents
1 Introduction ........................................................................................................9
1.1 Subject of the Book .........................................................................................10
1.2 The IEC 61131 standard ..................................................................................12
1.2.1 Goals and benefits of the standard ................................................................12
Manufacturers (PLC hardware and software) ......................................................................... 13
Customers............................................................................................................................... 13
1.2.2 History and components ...............................................................................14
1.3 The OrganisationPLCopen ..............................................................................16
1.3.1 Aims..............................................................................................................16
1.3.2 Committees and fields of activity..................................................................17
1.3.3 Results ..........................................................................................................18
Certification ........................................................................................................................... 18
Exchange format for user programs........................................................................................ 19
2 Building Blocks of IEC 61131-3.......................................................................21
2.1 Introduction to the New Standard ....................................................................21
2.1.1 Structure of the building blocks ....................................................................22
Declaration of variables.......................................................................................................... 22
Code part of a POU................................................................................................................ 23
2.1.2 Introductory example written in IL ...............................................................25
2.1.3 PLC assignment ............................................................................................27
2.2 The Program Organisation Unit (POU) ...........................................................30
2.3 Elements of a POU ..........................................................................................32
2.3.1 Example ........................................................................................................33
2.3.2 Declaration part ............................................................................................34
Types of variables in POUs. ................................................................................................... 35
Characteristics of the POU interface ...................................................................................... 36
The formal parameters and return values of a POU................................................................ 37
External and internal access to POU variables ....................................................................... 37
2.3.3 Code part ......................................................................................................39
2.4 The Function Block .........................................................................................41
2.4.1 Instances of function blocks..........................................................................41
What is an “instance”? ........................................................................................................... 41
Instance means “structure”. ................................................................................................... 43
Instance means “memory”. .................................................................................................... 45
2 Contents
Relationship between FB instances and data blocks............................................................... 46
2.4.2 Re-usable and object-oriented FBs .............................................................. 47
2.4.3 Types of variables in FBs............................................................................. 48
2.5 The Function ................................................................................................... 48
2.5.1 Types of variables in functions and the function value ................................ 49
2.5.2 Execution control with EN and ENO ........................................................... 50
2.6 The Program.................................................................................................... 52
2.7 Calling Functions and Function Blocks........................................................... 53
2.7.1 Mutual calls of POUs................................................................................... 53
2.7.2 Recursive calls are forbidden ....................................................................... 54
2.7.3 Calling with formal parameters .................................................................... 56
2.7.4 Calls with input parameters omitted or in a different order.......................... 59
2.7.5 FB instances as actual FB parameters .......................................................... 60
Example of an indirect FB call. .............................................................................................. 62
FB instance names as actual parameters of functions............................................................. 63
Function values as actual parameters. .................................................................................... 63
2.8 Summary of POU Features.............................................................................. 64
3 Variables, Data Types and Common Elements.............................................. 65
3.1 Simple Language Elements ............................................................................. 65
3.1.1 Reserved keywords ..................................................................................... 67
3.2 Literals and Identifiers .................................................................................... 68
3.2.1 Literals ......................................................................................................... 68
3.2.2 Identifiers ..................................................................................................... 70
3.3 Meanings of Data Types and Variables........................................................... 71
3.3.1 From direct PLC addresses via symbols to variables ................................... 72
3.3.2 The data type determines the properties of variables ................................... 73
3.3.3 Type-specific use of variables...................................................................... 74
3.3.4 Automatic mapping of variables onto the PLC ............................................ 75
3.4 Data Types ...................................................................................................... 75
3.4.1 Elementary data types .................................................................................. 76
3.4.2 Derived data types (type definition) ............................................................. 77
Additional properties for elementary data types. .................................................................... 78
Arrays. .................................................................................................................................... 80
Data structures........................................................................................................................ 81
Initial values in type definitions. ............................................................................................ 83
3.4.3 Generic data types........................................................................................ 84
3.5 Variables ......................................................................................................... 85
3.5.1 Inputs, outputs and flags as deosebit variables ............................................... 86
3.5.2 Multi-element variables: arrays and structures............................................. 88
3.5.3 Assignment of initial values at the start of a program .................................. 90
3.5.4 Attributes of variable types .......................................................................... 91
3.5.5 Graphical representation of variable declarations ........................................ 93
Contents 3
4 The New Programming Languages of IEC 61131-3 ......................................95
4.1 Instruction List IL ............................................................................................96
4.1.1 Instruction in IL ............................................................................................96
4.1.2 The universal accumulator (Current Result) .................................................97
4.1.3 Operators ....................................................................................................100
Negation of the operand. ...................................................................................................... 100
Nesting levels by parenthesis................................................................................................ 100
Conditional execution of operators....................................................................................... 101
4.1.4 Using functions and function blocks...........................................................104
Calling a function. ................................................................................................................ 104
Calling a function block. ...................................................................................................... 106
4.1.5 IL example: Mountain railway....................................................................107
4.2 Structured Text ST.........................................................................................111
4.2.1 ST statements..............................................................................................111
4.2.2 Expression: Partial statement in ST ...........................................................113
Operands. ............................................................................................................................. 113
Operators. ............................................................................................................................. 113
Function as operator. ............................................................................................................ 115
4.2.3 Statement: Assignment................................................................................116
4.2.4 Statement: Call of function blocks..............................................................118
4.2.5 Statement: RETURN ..................................................................................118
4.2.6 Statement: Selection and Multi- selection...................................................119
Selection............................................................................................................................... 119
Multi- selection. ................................................................................................................... 120
4.2.7 Statement: Iteration.....................................................................................122
WHILE and REPEAT statements. ........................................................................................ 122
FOR statement...................................................................................................................... 123
EXIT statement..................................................................................................................... 125
4.2.8 Example: Stereo cassette recorder ..............................................................125
4.3 Function Block Diagram FBD.......................................................................128
4.3.1 Networks, graphical elements and connections of LD and FBD.................128
Network label. ...................................................................................................................... 128
Network comment. ............................................................................................................... 129
Network graphic. .................................................................................................................. 129
4.3.2 Network architecture in FBD......................................................................131
4.3.3 Graphical objects in FBD ...........................................................................133
Connections.......................................................................................................................... 134
Execution control (jumps). ................................................................................................... 134
Call of functions and function blocks................................................................................... 135
4.3.4 Programming methods in FBD ...................................................................136
Network evaluation. ............................................................................................................. 136
Feedback variable................................................................................................................. 137
4.3.5 Example: Stereo cassette recorder ..............................................................137
Comments on the networks of Example 4.24 and Example 4.31 ......................................... 140
4 Contents
4.4 Ladder Diagram LD...................................................................................... 141
4.4.1 Networks, graphical elements and connections (LD)................................. 141
4.4.2 Network architecture in LD........................................................................ 141
4.4.3 Graphical objects in LD............................................................................. 142
Connections.......................................................................................................................... 142
Contacts and coils. ............................................................................................................... 143
Execution control. ................................................................................................................ 147
Call of functions and function blocks................................................................................... 148
4.4.4 Programming methods in LD..................................................................... 149
Network evaluation. ............................................................................................................. 149
Feedback variable................................................................................................................. 151
4.4.5 Example in Ladder Diagram: Mountain railway ........................................ 153
Comments on the mountain railway networks...................................................................... 156
4.5 The American way of Ladder programming ................................................. 159
4.5.1 Network Layout.......................................................................................... 159
4.5.2 Module addresses and memory areas ......................................................... 161
4.5.3 Configuration ............................................................................................. 163
4.6 Sequential Function Chart SFC..................................................................... 164
4.6.1 Step / Transition combination .................................................................... 165
4.6.2 Step - transition sequence........................................................................... 167
4.6.3 Detailed description of steps and transitions .............................................. 172
Step....................................................................................................................................... 172
Transition. ............................................................................................................................ 174
4.6.4 Step execution using action blocks and actions.......................................... 179
4.6.5 Detailed description of actions and action blocks ...................................... 181
Actions. ................................................................................................................................ 181
Action block. ........................................................................................................................ 182
4.6.6 Relationship between step, transition, action and action block .................. 185
4.6.7 Action qualifiers and execution control ..................................................... 189
Qualifier. .............................................................................................................................. 189
Sequential control................................................................................................................. 195
4.6.8 Example: “Dino Park”................................................................................ 196
Comments on the network for the dinosaur park.................................................................. 200
5 Standardised PLC Functionality .................................................................. 201
5.1 Standard Functions........................................................................................ 202
5.1.1 Overloaded and extensible functions.......................................................... 206
Overloaded functions............................................................................................................ 206
Extensible functions ............................................................................................................. 208
Contents 5
5.1.1 Examples ....................................................................................................209
Type conversion functions.................................................................................................... 210
Numerical functions ............................................................................................................. 211
Arithmetic functions............................................................................................................. 211
Bit-shift functions ................................................................................................................ 212
Bitwise Boolean functions.................................................................................................... 212
Selection functions ............................................................................................................... 213
Comparison functions .......................................................................................................... 214
Character string functions .................................................................................................... 215
Functions for time data types. .............................................................................................. 215
Functions for enumerated data types .................................................................................... 216
5.2 Standard Function Blocks..............................................................................217
5.2.2 Examples ....................................................................................................218
Bistable element (flipflop).................................................................................................... 220
Edge detection...................................................................................................................... 221
Counter................................................................................................................................. 223
Timer .................................................................................................................................... 224
6 State-of-the-Art PLC Configuration.............................................................227
6.1 Structuring Projects with Configuration Elements.........................................227
6.2 Elements of a Real-World PLC Configuration ..............................................228
6.3 Configuration Elements .................................................................................230
6.3.1 Definitions ..................................................................................................230
6.3.2 The CONFIGURATION ............................................................................231
6.3.3 The RESOURCE ........................................................................................232
6.3.4 The TASK with run-time program..............................................................233
6.3.5 ACCESS declarations .................................................................................236
6.4 Configuration Example..................................................................................237
6.5 Communication between Configurations and POUs......................................240
7 Innovative PLC Programming Systems........................................................243
7.1 Requirements of Innovative Programming Tools ..........................................243
7.2 Technological Change ...................................................................................244
7.2.1 Processor performance................................................................................244
7.2.2 Full-graphics display and printout ..............................................................244
7.2.3 Operating systems.......................................................................................244
7.2.4 Uniform user interfaces...............................................................................245
7.3 Decompilation (Reverse Documentation)......................................................245
7.3.1 No decompilation........................................................................................246
7.3.2 Decompilation with symbols and comments...............................................246
7.3.3 Decompilation including graphics ..............................................................246
7.3.4 Sources stored in the PLC...........................................................................247
7.4 Language Compatibility.................................................................................247
6 Contents
7.4.1 Cross-compilation ...................................................................................... 248
The motivation for cross-compilation................................................................................... 248
Different approaches in graphical and textual languages. .................................................... 249
Differences in languages affect cross-compilation. .............................................................. 250
Restrictions in LD/ FBD....................................................................................................... 251
Restrictions in IL/ ST. .......................................................................................................... 251
Cross-compilation IL / ST. ................................................................................................... 251
Full cross-compilation only with additional information...................................................... 252
Quality criteria for cross-compilation................................................................................... 253
7.4.2 Language independence ............................................................................. 254
7.5 Documentation .............................................................................................. 255
7.5.1 Cross-reference list..................................................................................... 255
7.5.2 Allocation list (wiring list) ......................................................................... 256
7.5.3 Comments .................................................................................................. 257
7.6 Project Manager ............................................................................................ 257
7.7 Test & Commissioning Functions ................................................................. 261
7.7.1 Program transfer......................................................................................... 261
7.7.2 Online modification of a program.............................................................. 262
7.7.3 Remote control: Starting and stopping the PLC......................................... 263
7.7.4 Variable and program status....................................................................... 263
7.7.5 Forcing ....................................................................................................... 267
7.7.6 Program test ............................................................................................... 268
7.7.7 Testing Sequential Function Chart programs ............................................. 269
7.8 Data Blocks and Recipes............................................................................... 269
7.9 FB Interconnection........................................................................................ 273
7.9.1 Data exchange and co-ordination of blocks in distributed systems ............ 273
7.9.2 Macro techniques in FB interconnection.................................................... 275
7.10 Diagnostics, Error Detection and Error Handling ....................................... 276
Error concept of IEC 61131-3. ............................................................................................. 277
Extended error handling model (beyond IEC). ..................................................................... 277
7.11 Hardware-Dependence................................................................................ 279
7.12 Readiness for New Functionality ................................................................ 279
7.12.1 Exchange of programs and data ............................................................... 280
7.12.2 Extension with additional software packages........................................... 281
8 Main Advantages of IEC 61131-3................................................................. 283
8.1 Convenience and Security with Variables and Data Types ........................... 283
8.2 Blocks with Extended Capabilities................................................................ 284
8.3 PLC Configuration with Run-Time Behaviour.............................................. 285
8.4 Uniform Programming Languages ................................................................ 286
8.5 Structured PLC Programs.............................................................................. 286
8.6 Trend towards Open PLC Programming Systems ........................................ 286
8.7 Conclusion .................................................................................................... 288
Contents 7
9 Programming by Configuring with IEC 61499............................................289
9.1 Programming by FB Interconnection with IEC 61131-3 ...............................289
9.2 IEC 61499 – The Programming Standard for Distributed PLC Systems .......290
9.2.1 System model..............................................................................................291
9.2.2 Device model..............................................................................................291
9.2.3 Resource model ..........................................................................................292
9.2.4 Application model ......................................................................................293
9.2.5 Function block model .................................................................................294
Composite function blocks................................................................................................... 296
9.2.6 Creating an application ...............................................................................298
9.3 Overview of the Parts of IEC 61499..............................................................298
10 Contents of CD-ROM...................................................................................299
10.1 IEC Programming Systems STEP 7 and OpenPCS .....................................299
Demo versions of STEP 7 (Siemens) and OpenPCS (infoteam)........................................... 299
IL examples .......................................................................................................................... 300
10.2 Buyer's Guide for IEC 61131-3 PLC Programming Systems ......................300
A Standard Functions........................................................................................301
A.1 Type Conversion Functions .........................................................................302
A.2 Numerical Functions ....................................................................................303
A.3 Arithmetic Functions....................................................................................304
A.4 Bit-Shift Functions.......................................................................................305
A.5 Bitwise Boolean Functions ..........................................................................306
A.6 Selection Functions for Max., Min. and Limit .............................................307
A.7 Selection Functions for Binary Selection and Multiplexers .........................308
A.8 Comparison Functions ..................................................................................310
A.9 Character String Functions...........................................................................311
A.10 Functions for Time Data Types..................................................................313
A.11 Functions for Enumerated Data Types.......................................................314
B Standard Function Blocks .............................................................................315
B.1 Bistable Elements (Flip-Flops)......................................................................316
B.2 Edge Detection..............................................................................................317
B.3 Counters ........................................................................................................318
B.4 Timers ...........................................................................................................320
C IL Examples....................................................................................................323
C.1 Example of a FUNCTION ............................................................................323
C.2 Example of a FUNCTION_BLOCK.............................................................325
C.3 Example of a PROGRAM.............................................................................327
D Standard Data Types .....................................................................................331
E Causes of Error ..............................................................................................333
8 Contents
F Implementation-Dependent Parameters ...................................................... 335
G IL Syntax Example........................................................................................ 339
G.1 Syntax Diagrams for IL ................................................................................ 340
G.2 IL Example from Syntax Diagrams .............................................................. 347
H Reserved Keywords and Delimiters............................................................. 349
H.1 Reserved Keywords...................................................................................... 349
H.2 Delimiters ..................................................................................................... 353
I Planned Amendments to the Standard ......................................................... 357
J Glossary .......................................................................................................... 359
K Bibliography .................................................................................................. 365
L Index ............................................................................................................... 331
Author Biographies........................................................................................... 375
Karl-Heinz John .................................................................................................. 375
Michael Tiegelkamp..........................................................................................

http://en.file-upload.net/download-8382363/IEC-61131-3-Programming-Industrial-Automation-Systems.rar.html