User manual

41Publication 1756-RM093F-EN-P - January 2010 41
Chapter 5
Characteristics of Safety Tags, the Safety
Task, and Safety Programs
Introduction
This chapter explains how to use the standard and safety components
of the GuardLogix system.
Differentiate Between
Standard and Safety
Because it is a Logix series controller, both standard
(non-safety-related) and safety-related components can be used in the
GuardLogix control system.
You can perform standard automation control from standard tasks
within a GuardLogix project. 1756 GuardLogix controllers provide the
same functionality as other 1756 ControlLogix series controllers. 1768
Compact GuardLogix controllers provide the same functionality as
other 1768-L4x CompactLogix controllers. What differentiates 1756
and 1768 GuardLogix controllers from standard controllers is that they
provide a SIL 3-capable safety task.
However, a logical and visible distinction is required between the
standard and safety-related portions of the application. RSLogix 5000
software provides this differentiation via the safety task, safety
programs, safety routines, safety tags, and safety I/O modules. You
can implement both SIL 2 and SIL 3 levels of safety control with the
safety task of the GuardLogix controller.
Topic Page
Differentiate Between Standard and Safety 41
SIL 2 Safety Applications 42
SIL3 Safety – the Safety Task 47
Safety Programs 49
Safety Routines 50
Safety Tags 50
Additional Resources 52