Chapter 13 Structured Texts Table of Contents 13.1 Introducing Structured Texts ....................................................... 13-2 13.1.1 Basic Structure of a Structured Text ........................................... 13-2 13.1.2 Statement .............................................................................. 13-3 13.1.3 Expression .............................................................................. 13-4 13.1.4 Operand and Operator .............................................................. 13-5 13.1.5 Keyword and Comment.............................................................
13-6 13.1.6 Using Array Symbols in ST ........................................................ 13-8 13.1.7 Notes on ST Programming ......................................................... 13-8 13.2 Structure of a Statement ............................................................ 13-11 13.2.1 Assignment Structure─:=........................................................ 13-11 13.2.2 Conditional Structure - IF ........................................................ 13-13 13.2.4 Loop Structure - REPEAT ......................................................... 13-18 13.2.3 Conditional Structure─CASE ....................................................
13-15 13.2.5 Loop Structure - WHILE .......................................................... 13-19 13.2.6 Loop Structure - FOR .............................................................. 13-20 13.2.7 Applied Instruction Structure ................................................... 13-22 13.2.8 Function Block Structure ......................................................... 13-23 13.2.9 Blank Statement .................................................................... 13-25 13.2.10 RETURN Statement ................................................................ 13-25 13.2.11 EXIT Statement .....................................................................
13-26 13.3 Create a Structured Text in ISPSoft ............................................ 13-27 13.3.1 ST Editing Environment .......................................................... 13-27 13.3.2 Edit Structured Text ............................................................... 13-28 13.3.3 Insert API and Function Blocks ................................................. 13-29 13.3.4 Bookmark ............................................................................. 13-31 13.4 Example of a Structured Text ..................................................... 13-32 13.4.1 Explanation ...........................................................................
13-32 13.4.2 Planning Hardware ................................................................. 13-32 13.4.3 Planning a Program ................................................................ 13-32 13.4.4 Creating a Program ................................................................ 13-33 13-1