Specifications

5-10

5.1 ST

5.1.5 Calling function blocks in ST language

The following description is used to call a function block in the ST language.

Enclose the assignment syntax that assigns variables to the input variable and output variable by

'( )' after the instance name.

When using multiple variables, delimit assignment syntax by ',' (comma).

The execution result of the function block is stored by assigning the output variable that is

specified by adding '.' (period) after the instance name to the variable.

1) Calling a function block with one input variable and one output variable

The following is the description to call the function block above.

2) Calling a function block with three input variables and two output variables

The following is the description to call the function block above.

Arguments using at function block call;

VAR_OUTPUT is not appeared on a template if a checkbox in the following option

window is not selected;

[Tools]

 [Options] "Convert" "Structured Ladder/FBD/ST""Compile

Condition1"

"Allow VAR_OUTPUT at FB call (ST)".

Instance name(Input variable1:= Variable1, ... Output variable1: = Variable2, ...);

FB definition

FB Name: FBADD

FB instance name: FBADD1

Input variable1: IN1

Output variable1: OUT1

FBADD1(IN1:=Input1);

Output1:=FBADD1.OUT1;

FB definition

FB Name: FBADD

FB instance name: FBADD1

Input variable1: IN1

Input variable2: IN2

Input variable3: IN3

Output variable1: OUT1

Output variable2: OUT2

FBADD1(IN1:=Input1, IN2:=Input2, IN3:= Input3);

Output1:=FBADD1.OUT1;

Output2:=FBADD1.OUT2;