IEC 61131-3:1993

Programmable controllers - Part 3: Programming languages

Automates programmables - Partie 3: Langages de programmation

S'applique à la représentation imprimée et affichée, à l'aide des caractères ISO/CEI 646, des langages de programmation devant être utilisés pour les automates programmables. Spécifie la syntaxe et la sémantique.

General Information

• Status: Published
• Publication Date: 21-Mar-1993
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.060 - Languages used in information technology
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: SC 65B - Measurement and control devices
• Drafting Committee: WG 7 - TC 65/SC 65B/WG 7
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 22-Jan-2003

Relations

• Revised: IEC 61131-3:2003 - Programmable controllers - Part 3: Programming languages
• Effective Date: 05-Sep-2023

Standards Content (Sample)

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CONTENTS
Page
FOREWORD. 7

Clause
1  General . 9

1.1  Scope . 9
1.2  Normative references . 9
1.3  Definitions . 10
1.4  Overview and general requirements . 15
1.4.1  Software model . 15
1.4.2  Communication model . 17
1.4.3  Programming model . 19
1.5  Compliance . 21
1.5.1  Programmable controller systems. 22
1.5.2  Programs. 23
2  Common elements . 24
2.1  Use of printed characters . 24
2.1.1  Character set. 24
2.1.2  Identifiers. 25
2.1.3  Keywords . 26
2.1.4  Use of spaces . 26
2.1.5  Comments . 26
2.2  External representation of data . 26
2.2.1  Numeric literals . 26
2.2.2  Character string literals . 27
2.2.3  Time literals . 28
2.3  Data types . 30
2.3.1  Elementary data types . 30
2.3.2  Generic data types . 31
2.3.3  Derived data types . 32
2.4  Variables . 36

2.4.1  Representation . 36
2.4.2  Initialization . 38
2.4.3  Declaration . 39
2.5  Program organization units . 44
2.5.1  Functions. 44
2.5.2  Function blocks . 61
2.5.3  Programs. 76

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Clause Page
2.6  Sequential Function Chart (SFC) elements . 77

2.6.1  General . 77

2.6.2  Steps . 77

2.6.3  Transition . 79

2.6.4  Actions . 83

2.6.5  Rules of evolution. 92

2.6.6  Compatibility of SFC elements . 101

2.6.7  Compliance requirements . 101

2.7  Configuration elements . 102

2.7.1  Configurations, resources, and access paths . 103
2.7.2  Tasks. 105
3  Textual languages . 115
3.1  Common elements . 115
3.2  Language IL (Instruction List) . 115
3.2.1  Instructions . 115
3.2.2  Operators, modifiers and operands . 116
3.2.3  Functions and function blocks . 117
3.3  Language ST (Structured Text) . 118
3.3.1  Expressions. 118
3.3.2  Statements . 121
4  Graphic languages . 124
4.1  Common elements . 124
4.1.1  Representation of lines and blocks . 124
4.1.2  Direction of flow in networks . 125
4.1.3  Evaluation of networks . 126
4.1.4  Execution control elements . 128
4.2  Language LD (Ladder Diagram). 130
4.2.1  Power rails . 130
4.2.2  Link elements and states . 130
4.2.3  Contacts . 131
4.2.4  Coils . 131
4.2.5  Functions and function blocks . 131
4.2.6  Order of network evaluation . 131
4.3  Language FBD (Function Block Diagram) . 134

4.3.1  General . 134
4.3.2  Combination of elements . 134
4.3.3  Order of network evaluation . 134
Annexes
A Specification method for textual languages. 135
A.1 Syntax . 135
A.2 Semantics . 137

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Annexes (concluded)
B Formal specifications of language elements . 138

B.0 Programming model. 138
B.1 Common elements . 138
B.2 Language IL (Instruction List) . 148
B.3 Language ST (Structured Text) . 149

C Delimiters and keywords . 151

D Implementation-dependent parameters . 154

E Error conditions . 156
F Examples . 157
F.1 Function WEIGH . 157
F.2 Function block CMD_MONITOR. 158
F.3 Function block FWD_REV_MON . 161
F.4 Function block STACK_INT . 166
F.5 Function block MIX_2_BRIX . 171
F.6 Analog signal processing . 174
F.7 Program GRAVEL. 183
F.8 Program AGV. 191
G Index . 195
H Software compliance testing . 207
Tables
1 Character set features . 25
2 Identifier features . 25
3 Comment feature . 26
4 Numeric literals . 27
5 Character string literal feature .28
6 Two-character combinations in character strings . 28
7 Duration literal features. 29
8 Date and time of day literals .29
9 Examples of date and time of day literals . 30
10 Elementary data types .31
11 Hierarchy of generic data types . 32
12 Data type declaration features . 34

13 Default initial values . 34
14 Data type initial value declaration features . 35
15 Location and size prefix features for directly represented variables. 37
16 Variable declaration keywords . 40
17 Variable type assignment features . 41
18 Variable initial value assignment features . 43
19 Graphical negation of Boolean signals . 45
20 Use of EN input and ENO output . 47
21 Typed and overloaded functions . 49
22 Type conversion function features .
...