Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 27

For function blocks, both the FB definition and instance initial values can be set.
If both initial values are set, the initial values used will take the following priority.
Priority Type
High Instance initial value

FB definition initial value

Default initial value
Low
If two instances of a function block for which the FB definition initial value has been set are created and the
instance initial value is set for only one of them, the FB1 definition initial value will be used for the instance for
which the instance initial value has not been set and the instance initial value will be used for the other.
FB1 definition
FB1
Local label definition (FB1)
Label name
AAA
BBB
CCC
(1) When the instance initial value is not set, the FB definition initial value will be used.
(2) When the instance initial value is set, it will be used.
Global label definition
Label name
-
FB1_a
AAA
BBB
CCC
Local label definition
Initial value
(program block 1)
Label name
1111
2222
-
FB1_b
3333 3333
AAA
BBB
CCC
Remarks


Used if neither the instance nor FB definition initial value has been set.
(1)
Initial value
-
1111
2222
3333
(2)
Initial value
-
7777
8888
9999
3 PROGRAM ORGANIZATION UNITS
3.3 Function Blocks (FB)
3
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