Rockwell Automation Logix5000 Controllers Add-on Instructions Programming Manual - Manual (Page 81)

Using Add-On Instructions Chapter 3
the down arrow and choose the module reference parameter from the
program.
You can now access the attributes associated with the Module Object from within
the Add-On Instruction.
This table describes programming tips for you to reference when using Add-On
Instructions.
Topic Description
Instruction Help Use the instruction help to determine how to use the instruction in your code.
Ladder Rungs
In a ladder rung, consider if the instruction should be executed on a false rung condition. It
may improve scan time to not execute it.
Data Types
A data type defined with the Add-On Instruction is used for the tag that provides context
for the execution from your code. A tag must be defined of this Add-On
Instruction-defined type on the call to the instruction.
Indexed Tag
You can use an indirect array indexed tag for the Instruction instance. One drawback is
that you cannot monitor the Add-On Instruction by using this as a data context.
Passing Data
• Input and Output parameters are passed by value.
• InOut parameters are passed by reference.
Follow these procedures for any language when you want to access an Add-On
Instruction parameter that isn't available on the instruction face by default.
Tips for using an Add-On
Instruction
Programmatically access a
parameter
Rock well Automati on Publication 1756- PM010F-EN-P - Oct ober 2014 81