C Control The I Unit-M Advanced 5 Vdc Inputs / outputs 16 x digital I/Os / 8 x analogue or digital I/Os Program memory 2 198805 Datenbogen

To create a simple program loop, you should use DO LOOP UNTIL. The loop is executed at least one time 
and may be quit early with Exit Do. The Until instruction at the end of the loop checks the expression to be 
True or False. True will cause to exit the loop. 
 
The Exit Do can only be used within a Do...Loop control structure to provide an alternate way to exit a 
Do...Loop. Any number of Exit Do statements may be placed anywhere in the Do...Loop. Often used with the 
evaluation of some condition (for example, If...Then), Exit Do transfers control to the statement immediately 
following the Loop.  
When used within nested Do...Loop statements, Exit Do transfers control to the loop that is one nested level 
above the loop where it occurs. 
 
 
 
Syntax: Do 

Loop (Until [expression])  

 
 
 
IF, THEN, ELSE END IF 
Conditionally executes a group of statements, depending on the value of an expression.  
 
You can use the single-line form (first syntax) for short, simple tests. However, the block form (second 
syntax) provides morestructure and flexibility than the single-line form and is usually easier to read, maintain, 
and debug. A block IF statement must be the first statement on a line. The block IF must end with an END IF 
statement. 
 
Syntax1:     If [expression] Then [instruction] [Else] [instruction] 

End If  

 
 
 
 
 
 
 
SELECT CASE, CASE, CASE  ELSE 
 Executes one of several groups of statements, depending on the value of an expression.  
 
If matchexpression matches any Case expression, the statements following that CASE clause are executed 
up to the next CASE clause, or for the last clause, up to END SELECT. Control then passes to the statement 
following END SELECT If matchexpression matches an expression in more than one CASE clause, only the 
statements following the first match are executed. 
 
The CASE ELSE clause is used to indicate the elseinstructions to be executed if no match is found between 
the matchexpression and an Case expression in any of the other Case selections. Although not required, it is 
a good idea to have a CASE ELSE statement in your SELECT CASE block to handle unforeseen 
matchexpression values. If no Case expression matches matchexpression and there is no CASE ELSE 
statement, execution continues at the statement following END SELECT