TABLE OF CONTENTS This appendix contains a list of keywords used in the IEC languages. To avoid the possibility of having ambiguous language identifiers, the names of the following keywords should be regarded as reserved and not used as identifiers; see Chapter 3 for further details on identifiers.
| Keywords | Comments |
|---|---|
| N R S L D P SD DS SL | Action block qualifiers used in Sequential Function Charts |
| ACTION END_ACTION | Declares an action block body |
| ARRAY OF | Array variable definition |
| AT | Used to associate variables with directly represented variables |
| CASE OF ELSE END_CASE | Case statement in Structured Text |
| CONFIGURATION END_CONFIGURATION | Declares a configuration body |
| CONSTANT | Attribute of a variable |
| EN ENO | Control of functions and function blocks in Ladder Diagram language |
| EXIT | To exit from an iteration loop in Structured Text |
| FALSE | Boolean literal (constant) for false or = 0 |
| F_EDGE | Falling edge data type |
| FOR TO BY DO END_FOR | Iteration constructs in Structured Text |
| FUNCTION END_FUNCTION | Declares a function body |
| FUNCTION_BLOCK END_FUNCTION_BLOCK | Declares a function block body |
| IF THEN ELSIF ELSE END_IF | Conditional statements in Structured Text |
| INITIAL_STEP END_STEP | Declares an initial step body |
| NON_RETAIN | Attribute of a variable that defines that its value is never retained when there is a powerfail [1] |
| PROGRAM WITH | Used to configure a program |
| PROGRAM END_PROGRAM | Declares a program body |
| R_EDGE | Rising edge data type |
| READ_ONLY READ_WRITE | Attributes of a variable |
| REPEAT UNTIL END_REPEAT | Iteration constructs in Structured Text |
| RESOURCE ON END_RESOURCE | Used in resource configuration |
| RETAIN | Attribute of a variable that defines that the value is... |
