Lenze DDS v2.3 - Manual (Page 46)

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DDS EN 2.3
4.3.9 FOR loop
Use the FOR loop to program repetitive procedures.
Syntax:
INT_Var :INT;
FOR <INT_Var>:=<INIT_VALUE> TO <END_VALUE> {BY <step size>} DO
<instructions>
END_FOR ;
•
The part in curly brackets {} is optional.
•
The <instructions> are executed as long as the counter<INT_Var> is not greater than
the<END_VALUE>.
•
A check is performed before the <instructions> are executed so that the
<instructions>
will never be executed if <INIT_VALUE> is greater than <END_VALUE>.
•
Whenever the section <instructions> has been executed, <INT_Var> will be increased
by <step size>.
•
The step size can have any integer value. If no other step size is specified, step size 1 will be
used. The loop must terminate because <INT_Var> will only become greater.
•
If <INIT_VALUE> is greater than <END_VALUE> and <step size> is negative, the FOR
loop is counted in opposite direction.
•
If <INIT_VALUE> is less than <END_VALUE> and <step size> is negative, the FOR loop
will not be executed.
Example:
FOR Counter:=1 TO 5 BY 1 DO
Var1:=Var1*2;
END_FOR ;
Res:=Var1;
Assuming that the variable Var1 has been pre-assigned value 1, it will be 32 after the FOR loop.
Caution!
<END_VALUE> must not be the limit value of the counter <INT_VAR>.
If, for instance, the variable Counter is of type SINT, <END_VALUE> must not be 127 since
otherwise the loop would be endless.
After completion of the FOR loop, Counter has a value 6.
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