Case...of, Operands, Description – Rockwell Automation Logix5000 Controllers Structured Text Programming Manual User Manual
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Publication 1756-PM007D-EN-P - November 2012
25
Program Structured Text Chapter 1
CASE...OF
Use CASE to select what to do based on a numerical value.
Operands:
Structured Text
Description:
The syntax is:
Operand
Type
Format
Enter
numeric_
expression
SINT
INT
DINT
REAL
Tag
Expression
Tag or expression that evaluates to a
number (numeric expression)
selector
SINT
INT
DINT
REAL
Immediate
Same type as
numeric_expression
IMPORTANT
If you use REAL values, use a range of values for a selector
because a REAL value is more likely to be within a range of
values than an exact match of one, specific value.
CASE numeric_expression OF
selector1: statement;
selectorN: statement;
ELSE
statement;
END_CASE;
CASE numeric_expression OF
Specify as many
alternative selector
values (paths) as you
need
selector1 :
<statement>;
.
.
.
Statements to execute when
numeric_expression = selector1
selector2 :
<statement>;
.
.
.
Statements to execute when
numeric_expression = selector2
selector3 :
<statement>;
.
.
.
Statements to execute when
numeric_expression = selector3