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Planning your add-on instruction design, Intended behavior – Rockwell Automation Logix5000 Controllers Add-on Instructions Programming Manual User Manual

Page 36

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Chapter 1

Designing Add-On Instructions

Take time to plan your instruction design. Advance planning can identify issues
that need to be addressed. When defining the requirements of an instruction, you

are also determining the interface. Keep the following aspects in mind when

defining your instruction requirements and creating your Add-On Instruction.

Intended behavior

• What is the purpose for creating the Add-On Instruction?
• What problem is it expected to solve?
• How is it intended to function?
• Do you need to higher level of integrity on your Add-On Instruction?

If so, you can generate an instruction signature as a means to verify that your
Add-On Instruction has not been modified.

• Do you need to use safety application instructions and certify your safety

Add-On Instruction to SIL-3 integrity?
For details on how to certify a safety Add-On Instruction, refer to the

GuardLogix Controller Systems Safety Reference Manual

, publication

1756-RM093.

Planning your Add-On

Instruction design

36

Rockwell Automation Publication 1756-PM010F-EN-P - October 2014