100BBasic instructions
7.8 Program control
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
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7.8
Program control
7.8.1
Overview of SCL program control statements
Structured Control Language (SCL) provides three types of program control statements for
structuring your user program:
●
Selective statements: A selective statement enables you to direct program execution into
alternative sequences of statements.
●
Loops: You can control loop execution using iteration statements. An iteration statement
specifies which parts of a program should be iterated depending on certain conditions.
●
Program jumps: A program jump means an immediate jump to a specified jump
destination and therefore to a different statement within the same block.
These program control statements use the syntax of the PASCAL programming language.
Table 7- 92 Types of SCL program control statements
Program control statement
Description
(Page 210)
Enables you to direct program execution into one of two alternative
branches, depending on a condition being TRUE or FALSE
Selective
(Page 211)
Enables the selective execution into 1 of
n
alternative branches, based
on the value of a variable
(Page 212)
Repeats a sequence of statements for as long as the control variable
remains within the specified value range
(Page 213)
Repeats a sequence of statements while an execution condition
continues to be satisfied
Loop
Repeats a sequence of statements until a terminate condition is met
(Page 214)
Stops the execution of the current loop iteration
(Page 215)
Exits a loop at any point regardless of whether the terminate condition
is satisfied or not
(Page 216)
Causes the program to jump immediately to a specified label
Program jump
(Page 210)
Causes the program to exit the block currently being executed and to
return to the calling block
See also