Mitsubishi Electric MELSEC iQ-F Series Programming Manual page 25

■Creating instances
A function block needs to be instantiated to be used in programs.
By creating instances, a function block can be called and executed by a program block or another function block.
Declare instances with global labels or local labels.
Label type
Global label
*1
Local label
*1 Local labels can be declared as the local labels of a program block or function block. Local labels cannot be declared in a function.
Same function blocks can be instantiated with different names in a single POU.
Instance A
Function block
wLabel5
wLabel1 Input variable 1
wLabel6
wLabel2 Input variable 2
wLabel7
wLabel9
wLabel3 Input variable 3
Instance A
Function block
wLabel5
wLabel1 Input variable 1
wLabel6
wLabel2 Input variable 2
wLabel7 wLabel9
wLabel3 Input variable 3
(1) Same instances use the same internal variables.
(2) Different instances use different internal variables.
Instance type
Global FB
Local FB
wLabel8
Output variable
wLabel4
Local variable
(1)
wLabel8 wLabel10
Output variable wLabel4
wLabel11
Local variable wLabel12
Class
VAR_GLOBAL
VAR
(2)
Instance B
Function block
wLabel5
Input variable 1 wLabel8
Output variable
wLabel6
Input variable 1
wLabel7 wLabel9
Input variable 1 Local variable
3 PROGRAM ORGANIZATION UNITS
wLabel13
3.3 Function Blocks (FB)
3
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