Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 60)

L-force | PLC Designer
What is What in PLC Designer
58 DMS 3.2 EN 02/2011 TD29
When are executed, is always increased by . The
step size can have any integer value. If it is missing, then it is set to 1. The loop must
also end since only becomes greater.
Example:
FOR Counter:=1 TO 5 BY 1 DO
Var1:=Var1*2;
END_FOR;
Erg:=Var1;
Let us assume that the default setting for Var1 is the value 1. Then it will have the
value 32 after the FOR loop.
Note!
must not be equal to the limit value of the counter . For
example: If the variable Counter is of type SINT and if is 127, you will
get an endless loop.
WHILE loop
The WHILE loop can be used like the FOR loop with the difference that the break-off
condition can be any Boolean expression. This means you indicate a condition which,
when it is fulfilled, the loop will be executed.
Syntax:
WHILE
END_WHILE;
The are repeatedly executed as long as the
returns TRUE. If the is already FALSE at the first evaluation,
then the are never executed. If never assumes
the value FALSE, then the are repeated endlessly which causes a
relative time delay.