Rockwell Automation Logix5000 Controllers I/O and Tag Data Programming Manual - Manual (Page 67)

Data access control Chapter 4
As shown in the following example, the External Access list is unavailable for an
alias tag.
There may be many alias tags in a program. To locate an associated base tag to
assign an external access, use the Go To feature. See Find a base tag with Go To on
page 69 for details.
For other tag considerations, see External access availability on page 70 .
The Connection button (next to the Type box) becomes active when you select
either a produced or consumed tag type. The button displays a dialog box to set up
produced and consumed tag connections. See the
Logix5000 Controllers
Produced and Consumed Tags Programming Manual , publication 1756-PM011.
Set up external access in the Tag Properties dialog box
Use the Tag Properties dialog box to edit properties of existing tags. You can
change tag attributes and change tag types.
Follow these steps to choose an external access option for an existing tag.
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