36
Rockwell Automation Publication 1715-RM001A-EN-P - June 2019
Chapter 4
Using 1715 Hardware in a ControlLogix SIL 2 System
Add-On Instructions
The Add-On Instructions provide a mechanism to verify the validity of data that
is transferred between the ControlLogix controller and the 1715 adapter. When
you use the Add-On Instructions, the sender of the data adds check data to the
produced data. The receiver of the data uses the check data to verify the integrity
of the consumed data.
A 1715 SIL 2 Add-On Instruction must be added to the SIL 2 safety program for
EACH simplex or duplex 1715 module that has channels that are used within
SIL 2 safety function. Note that a duplex module only requires one Add-On
Instruction.
1715 SIL 2 Add-On Instructions must be imported into the RSLogix 5000®
project. Import only the Add-On Instructions you need based on your SIL 2
configuration. The CRC-calculator Add-On Instruction is imported when you
import any of the other Add-On Instructions.
IMPORTANT
To meet SIL 2 application requirements in a ControlLogix system while using
1715 I/O, you must use the 1715 Add-On Instructions described in the
following section.
See chapter 8 of
from complete information.
IMPORTANT
Before you import the Add-On Instructions to your project, you must do the
following:
• Add your I/O modules to the project in the I/O configuration tree and
configure them properly.
• SIL 2 = Yes must be selected when configuring the module. This creates the
data types and tags that you must use in the Add-On Instruction.
