194 Rockwell Automation Publication 1756-UM001M-EN-P - February 2012
Chapter 13 SIL 2 Certification
Typical SIL2 Configurations
SIL2-certified ControlLogix systems can be used in non-redundancy or
redundancy configurations. For the purposes of documentation, the various levels
of availability that can be achieved by using various ControlLogix system
configurations are referred to as fail-safe, high-availability, or fault-tolerant.
This table lists each system configuration and the hardware that is part of the
system’s safety loop.
Table 52 - SIL2 Configurations and Hardware Summary
With this system configuration The safety loop includes
Fail-safe Configuration, page 195 • Nonredundant controller
• Nonredundant communication modules
• Nonredundant remote I/O
High-availability Configuration, page 196 • Redundant controllers
• Redundant communication modules
• Nonredundant remote I/O
Fault-tolerant Configuration
, page 197 • Redundant controllers
• Redundant communication modules
• Redundant remote I/O
• I/O termination boards
Note that the system user is responsible the tasks listed here when any of
the ControlLogix SIL2 system configurations are used:
• The setup, SIL rating, and validation of any sensors or actuators connected to the
ControlLogix control system.
• Project management and functional testing.
• Programming the application software and the module configuration according
to the descriptions in the following chapters.
The SIL2 portion of the certified system excludes the development tools
and display/human machine interface (HMI) devices; these tools and
devices are not part of the safety loop.