GE PACSystems RX7i

Chapter 3. Program Data
44 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
3.7 Data Scope
Each of the user references has scope; that is, it may be available throughout the system, available to
all programs, restricted to a single program, or restricted to local use within a block.
User Reference Type
Range
Scope
%I, %Q, %M, %T, %S, %SA, %SB,
%SC, %G, %R, %W, %AI, %AQ,
convenience references, fault
locating references
Global
From any program, block, or host computer. Variables defined
in these registers have system (global) scope by default.
However, variables with local scope can also be assigned in
these registers.
Symbolic variable
Global
From any program, block, or host computer. Symbolic variables
have system (global) scope by default. However, symbolic
variables with local scope can be created using the naming
conventions for local variables.
I/O variable
Global
From any program, block, or host computer.
%P
Program
From any block, but not from other programs (also available to
a host computer).
%L
Local
From within a block only (also available to a host computer).
In an LD block:
▪ %P should be used for program references that are shared with other blocks.
▪ %L are local references that can be used to restrict the use of register data to that block. These
local references are not available to other parts of the program.
▪ %I, %Q, %M, %T, %S, %SA, %SB, %SC, %G, %R, %W, %AI, and %AQ references are available
throughout the system.