Rockwell Automation Publication 1715-RM001A-EN-P - June 2019
15
Features of the ControlLogix SIL 2 System
Chapter 2
Application Development
Requirements
The application software for the SIL2-related automation system is created using
the programming tool, that is, RSLogix 5000® software or the Studio 5000 Logix
Designer® application, according to IEC 61131-3.
The application program has to be created by using the programming tool and
contains the specific equipment functions that the ControlLogix system
implements. Parameters for the operating function are also entered into the
system with the programming software.
The safety concept of the SIL 2 ControlLogix system assumes the following:
• The user who is responsible for creating, operating, and maintaining the
application is fully qualified, specially trained, and experienced in safety
systems.
• The programming software is installed correctly.
• Control system hardware is installed in accordance with product
installation guidelines.
• User application code (user program) uses common and good design
practices.
• A test plan is documented and adhered to, including well-understood
proof test requirements and procedures.
• A well-designed validation process is defined and implemented.
• A well-designed Management of Change (MOC) procedure is in place
Security
In the ControlLogix system and in the programming software, protection
mechanisms are available that help prevent unintentional or unauthorized
modifications to the safety system.
The following tools can be employed for security reasons in a SIL2-certified
ControlLogix application:
• Source Protection
• FactoryTalk® AssetCentre
• FactoryTalk® Security
In RSLogix 5000® software, V18 and later, and in the Studio 5000 Logix
Designer® application, tags have two attributes: External Access and Constant.
External Access controls access from external applications like HMIs. It can have
values of read/write, read-only, or none. Set all SIL 2 safety-related tags to
read-only. The Constant attribute is either on or off. When enabled, it helps
IMPORTANT
This document does not cover the specifics of creating the application code. It is
assumed the use knows the requirements of IEC-61511 and their specific
application when designing their system. This document only covers the steps
if it is necessary for ControlLogix to meet SIL 2.
