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Statement Descriptions Section 5-5
2. The values that will be passed between variables are specified within pa-
rentheses after the instance name registered in step 1 (Calcu_execute in
this example), and a semi-colon marks the end of the statement, as shown
in the following example.
Calcu_execute (A:=B,C=>D) ;
The value of B is passed to A, and at the same time the value of C is re-
ceived at D.
A: Called function block definition’s input variable name
B: One of the following values, depending on the ST program being used
• Calling function block’s input variable or a constant (when ST is being
used in the function block’s instance)
• Global variable or local variable name (when ST is being used in an
ST task or SFC action program)
C: Called function block definition’s output variable name or constant
D: One of the following values, depending on the ST program being used
• Calling function block’s output variable or constant (when ST is being
used in the function block’s instance)
• Global variable or local variable name (when ST is being used in an
ST task or SFC action program)
■ Examples Showing Additional Details
The following two examples show how to actually use an ST program to call a
function block.
Example 1:
These examples show how to call a function block from each kind of source
program (ST task, SFC, and function block).
• Conditions:
A function block is called.
The called function block is written in ladder language or ST language.
Call Details
a. Calling a function block from an ST task or SFC program
(ST)
Example) ...
Instance_FB(...,...);
INSTANCE_FB is an instance name of
data type FUNCTIONBLOCK.
(ST)
Example) ...
(Ladder diagram)
Function block (FB)ST task
Function block (FB)
(ST)
Example) ...
Instance_FB(...,...);
SFC
N Stepn aaa
Action
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