Rockwell Automation Logix5000 Controllers Add-on Instructions Programming Manual - Manual (Page 58)

Chapter 2 Defining Add-On Instructions
If any parameters or tags become unverified due to the change of class, they are
identified on the Parameters and Local Tags tabs of the Add-On Instruction
Editor.
If any of the restrictions for safety Add-On Instructions are violated by changing
the class from standard to safety, one of the following errors is displayed and the
change does not succeed:
• Routines must be of Ladder Diagram type.
• Safety Add-On Instructions do not support the Postscan routine.
• One or more parameters or local tags have an invalid data type for a safety
Add-On Instruction.
You must edit the parameter, tag, or routine types before the class change can be
made.
Tip: If the safety controller project contains safety Add-On Instructions, you must remove them from the project
or change their class to standard before changing to a standard controller type.
You need to test and troubleshoot the logic of an instruction to get it working.
Tip: When a fault occurs in an Add-On Instruction routine, a fault log is created that contains extended
information useful for troubleshooting.
Before you test
Before you start to test an Add-On Instruction, do the following.
1. Open a project to debug offline.
Tip: Add-On Instructions can only be created or modified when offline. You can add, delete, or modify tag
arguments in calls to Add-On Instructions while editing online, but you cannot edit arguments inside the
Add-On Instruction while online.
2. Add the Add-On Instruction to the project, if it is not already there.
Testing the flow
1. Add a call to the instruction in a routine in the open project.
2. Assign any arguments to required parameters for your call.
3. Download the project.
Testing the Add-On
Instruction
58 Rockwell Automation Publication 1756-PM010F-EN-P - October 2014