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Safety tag mapping, Restrictions, Safety tag – Rockwell Automation 1768-L45S Compact GuardLogix Controllers User Manual

Page 86

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86

Rockwell Automation Publication 1768-UM002C-EN-P - April 2012

Chapter 6

Develop Safety Applications

Safety Tag Mapping

Controller-scoped standard tags cannot be directly accessed by a safety routine.
To allow standard tag data to be used within safety task routines, the Compact
GuardLogix controllers provide a safety tag mapping feature that lets standard tag
values be copied into safety task memory.

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.

Table 22 - Additional Resources

Resource

Description

Pages

57

61

Provides more information on setting the RPI and understanding
how the Max. Network Delay, Timeout Multiplier, and Network
Delay Multipliers affect the Connection Reaction Time

Chapter 8

Contains information on the CONNECTION_STATUS predefined
data type

Logix5000 Controllers Produced and Consumed
Tags Programming Manual, publication

1756-

PM011

Provides detailed information on using produced and consumed
tags

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 Controller Systems Safety Reference Manual, publication

1756-RM093

, for more information.

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