Rockwell Automation 1756-L7x GuardLogix 5570 Controllers - Manual (Page 82)

82 Rockwell Automation Publication 1756-UM022A-EN-P - November 2012
Chapter 6 Develop Safety Applications
Safety Routines Safety routines have all the attributes of standard routines, except that they exist
only in a safety program. At this time, only ladder diagram is supported for safety
routines.
Safety Tags A tag is an area of a controller’s memory where data is stored. Tags are the basic
mechanism for allocating memory, referencing data from logic, and monitoring
data. Safety tags have all the attributes of standard tags with the addition of
mechanisms certified to provide SIL 3 data integrity.
When you create a tag, you assign the following properties:
• Name
• Description (optional)
• Tag type
• Data type
• Scope
• Class
• Style
• External Access
You can also specify if the tag value should be a constant.
To create a safety tag, open the New Tag dialog box by right-clicking Controller
Tags or Program Tags and choosing New Tag.
TIP A watermark feature visually distinguishes a safety routine from a standard
routine.