Allen-Bradley Logix5000 Programming Manual

76 Publication 1756-PM004C-EN-P - October 2009
Chapter 4 Data Access Control
Add-On Instruction
Definition - Parameters
Tab
The External Access column is disabled if:
• InOut parameters, which are blank.
• EnableIn and EnableOut parameters, which default ‘Read
Only’.
• you do not have permission to change the external access
settings.
(1)
• the controller is online.
• the tag is an alias tag.
• the Add-On Instruction is in Source Protection mode.
• the row represents an expanded bit, or data member.
When creating a new parameter, changing usage causes the
External Access column auto update to default to:
• Input parameter - equipment phase input parameter and
Add-On Instruction input parameter.
• Output parameter - equipment phase output parameter and
Add-On Instruction output parameter.
• InOut parameter - External Access column cell is blank and
disabled.
Changing external access attributes will cause:
• an error message if you change a tag from Input or Output
parameter to InOut parameter and the present attribute is
either ‘Read/Write,’ or ‘Read Only’.
• no change if you switch between Input and Output
parameters.
• the value of the external access updates to the new target
for an alias.
Add-On Instruction
Definition - Local Tags
Tab
The External Access column is disabled if:
• you do not have permission to change external access
settings.
(1)
• the controller is online.
• the Add-On Instruction is in Source Protection mode.
• the row represents an expanded array dimension, bit, or data
member.
Add-On Instruction External Access Variables
Dialog Box/Window Considerations

Allen-Bradley Logix5000 Specifications

General

Brand	Allen-Bradley
Model	Logix5000
Category	Controller
Language	English