Local Data - GE PACSystems RXi User Manual

Chapter 6. Program Organization
6.1.6

Local Data

Each block or UDFB in a block-structured program has an associated local data block.
_MAIN's data block memory is referenced by %P; all other data block memories are
referenced by %L.
The size of the data block is dependent on the highest reference in its block for %L and in all
blocks for %P.
All blocks within the program can use data associated with the _MAIN block (%P). Blocks
and UDFBs can use their own %L data as well as the %P data that is available to all blocks.
The _MAIN block cannot use %L.
External blocks and parameterized blocks can use the Local Data (%L) of their calling block
as well as the %P data of the _MAIN block. If a parameterized block or external block is
called by MAIN, all %L references in the parameterized block or external block will actually be
references to corresponding %P references (for example, %L0005 = %P0005). In addition to
inheriting the Local Data of their calling blocks, parameterized blocks and external blocks
inherit the FST_EXE status of their calling blocks.
110
data
%P
_MAIN
block
data
%P
Inherits as %L
_MAIN
Block
PACSystems* RXi Distributed IO Controller User Manual
data
%L
Block
2
Data
%L
Block
3
Data
%L
Block
4
PSB 1
or
EB 1
data
%L
Inherits as %L
BLOCK
1
PSB 2
or
EB 2
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