Rockwell Automation 1756-L7x GuardLogix 5570 Controllers - Manual (Page 93)

Rockwell Automation Publication 1756-UM022A-EN-P - November 2012 93
Develop Safety Applications Chapter 6
Restrictions
Safety tag mapping is subject to these restrictions:
• The safety tag and standard tag pair must be controller-scoped.
• The data types of the safety and standard tag pair must match.
• Alias tags are not allowed.
• Mapping must take place at the whole tag level. For example, myTimer.pre
is not allowed if myTimer is a TIMER tag.
• A mapping pair is one standard tag mapped to one safety tag.
• You may not map a standard tag to a safety tag that has been designated as
a constant.
• Tag mapping cannot be modified when the following is true:
– The project is safety-locked.
– A safety task signature exists.
– The keyswitch is in RUN position.
– A nonrecoverable safety fault exists.
– An invalid partnership exists between the primary controller and safety
partner.
Create Tag Mapping Pairs
1. Choose Map Safety Tags from the Logic menu to open the Safety Tag
Mapping dialog box.
ATTENTION: When using standard data in a safety routine, you are responsible for providing
a reliable means of ensuring that the data is used in an appropriate manner. Using standard
data in a safety tag does not make it safety data. You must not directly control a SIL 3/PLe
safety output with standard tag data.
Refer to the GuardLogix 5570 Controller Systems Safety Reference Manual, publication
1756-RM099 , for more information.