Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 62)

L-force | PLC Designer
What is What in PLC Designer
60 DMS 3.2 EN 02/2011 TD29

If <Boolean expression> is produced already at the first TRUE evaluation, then
<Instructions> are executed only once. If <Boolean_expression> never assumes the
value TRUE, then the <Instructions> are repeated endlessly which causes a relative
time delay.
Note!
The programmer must make sure that no endless loop is caused. He does this by
changing the condition in the instruction part of the loop, for example by counting
up or down one counter.
Example:
REPEAT
Var1 := Var1*2;
Counter := Counter-1;
UNTIL
Counter=0
END_REPEAT;
EXIT instruction
If the EXIT instruction appears in a FOR, WHILE, or REPEAT loop, then the innermost
loop is ended, regardless of the break-off condition.