Rockwell Automation Logix5000 Controllers I/O and Tag Data Programming Manual - Manual (Page 68)

Chapter 4 Data access control
1. In the Tag Editor, right-click a tag and then click Edit (tag name)
Properties.
2. In the Tag Properties dialog box, in the Type list, choose a tag type.
3. In the External Access list, choose an external access option.
The External Access list is unavailable for an alias tag. If a tag is a module
tag, the only external access option is Read/Write.
See External access availability on page 70 for other considerations.
4. Click OK.
68 Rockwell Automation Publication 1756-PM004E-EN-P - October 2014