Rockwell-automation Logix5000 Controllers Structured Text Programming Manuale Utente Pagina 1

Logix5000 Controllers Structured TextCatalog Numbers 1756 ControlLogix, 1769 CompactLogix, 1789 SoftLogix, 1794 FlexLogix, PowerFlex 700S with DriveL

10 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextInstruction(see page 20)An instruction is a standalone statemen

Publication 1756-PM007D-EN-P - November 2012 11Program Structured Text Chapter 1AssignmentsUse an assignment to change the value stored within

12 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextSpecify a Non-retentive AssignmentThe non-retentive assignment

Publication 1756-PM007D-EN-P - November 2012 13Program Structured Text Chapter 1Assign an ASCII Character to a StringUse the assignment operato

14 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextIn structured text, you use two types of expressions:BOOL expre

Publication 1756-PM007D-EN-P - November 2012 15Program Structured Text Chapter 1Use Arithmetic Operators and FunctionsYou can combine multiple

16 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextFor example:Use Relational OperatorsRelational operators compar

Publication 1756-PM007D-EN-P - November 2012 17Program Structured Text Chapter 1For example:How Strings Are EvaluatedThe hexadecimal values of

18 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextUse Logical OperatorsLogical operators let you check if multipl

Publication 1756-PM007D-EN-P - November 2012 19Program Structured Text Chapter 1Use Bitwise OperatorsBitwise operators manipulate the bits with

Important User InformationSolid state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines

20 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextInstructionsStructured text statements can also be instructions

Publication 1756-PM007D-EN-P - November 2012 21Program Structured Text Chapter 1ConstructsConstructs can be programmed singly or nested within

22 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextIF...THENUse IF…THEN to do something if or when specific condit

Publication 1756-PM007D-EN-P - November 2012 23Program Structured Text Chapter 1This table summarizes combinations of IF, THEN, ELSIF, and ELSE

24 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextExample 3: IF…THEN…ELSIFThe [:=] tells the controller to clear

Publication 1756-PM007D-EN-P - November 2012 25Program Structured Text Chapter 1CASE...OFUse CASE to select what to do based on a numerical val

26 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextThe syntax for entering the selector values is:The CASE constru

Publication 1756-PM007D-EN-P - November 2012 27Program Structured Text Chapter 1ExampleThe [:=] tells the controller to also clear the outlet t

28 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextFOR…DOUse the FOR…DO loop to do something a specific number of

Publication 1756-PM007D-EN-P - November 2012 29Program Structured Text Chapter 1Description: The syntax is:These diagrams show how a FOR...DO l

3Publication 1756-PM007D-EN-P - November 2012 3Summary of ChangesThis manual contains new and updated information. Changes throughout this revision ar

30 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextExample 1:Example 2:If you want this Enter this structured text

Publication 1756-PM007D-EN-P - November 2012 31Program Structured Text Chapter 1WHILE…DOUse the WHILE…DO loop to keep doing something as long a

32 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextThese diagrams show how a WHILE...DO loop executes and how an E

Publication 1756-PM007D-EN-P - November 2012 33Program Structured Text Chapter 1Example 2:If you want this Enter this structured textMove ASCII

34 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextREPEAT…UNTILUse the REPEAT…UNTIL loop to keep doing something u

Publication 1756-PM007D-EN-P - November 2012 35Program Structured Text Chapter 1These diagrams show how a REPEAT...UNTIL loop executes and how

36 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextExample 2:If you want this Enter this structured textMove ASCII

Publication 1756-PM007D-EN-P - November 2012 37Program Structured Text Chapter 1CommentsTo make your structured text easier to interpret, add c

38 Publication 1756-PM007D-EN-P - November 2012Chapter 1 Program Structured TextFor example:Format Example//comment At the beginning of a line/

4 Publication 1756-PM007D-EN-P - November 2012Summary of ChangesNotes:

Publication 1756-PM007D-EN-P - November 2012 41Supersedes Publication 1756-PM007C-EN-P - October 2009 Copyright © 2012 Rockwell Automation, Inc. All r

5Publication 1756-PM007D-EN-P - November 2012 5Table of ContentsPrefaceStudio 5000 Engineering and Design Environment and Logix Designer Application.

6 Publication 1756-PM007D-EN-P - November 2012Table of Contents

7Publication 1756-PM007D-EN-P - November 2012 7PrefaceStudio 5000 Engineering and Design Environment and Logix Designer ApplicationThe Studio 5000™ En

8 Publication 1756-PM007D-EN-P - November 2012Preface How to Use this ManualSome text is formatted differently from the rest of the text.Text t

Publication 1756-PM007D-EN-P - November 2012 9Chapter 1Program Structured TextIntroductionStructured text is a textual programming language that uses