Safety task signature, Hmi devices – Rockwell Automation 1768-L45S Compact GuardLogix Controllers User Manual
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Rockwell Automation Publication 1768-UM002C-EN-P - April 2012
Chapter 1
System Overview
For information on assigning the SNN, see
Safety Task Signature
The safety task signature consists of an ID number, date, and time that uniquely
identifies the safety portion of a project. This includes safety logic, data, and
configuration. The Compact GuardLogix system uses the safety task signature to
determine the project’s integrity and to let you verify that the correct project is
downloaded to the target controller. Creating, recording, and verifying the safety
task signature is a mandatory part of the safety-application development process.
See
Generate a Safety Task Signature on page 90
for more information.
Distinguishing Between
Standard and Safety
Components
Slots in the Compact GuardLogix backplane may be populated with other
CompactLogix I/O modules that are certified to the Low Voltage and EMC
Directives. Refer to
to find the CE
certificate for the Programmable Control – CompactLogix Product Family and
determine which modules are certified.
You must create and document a clear, logical, and visible distinction between the
safety and standard portions of the application. To aid in creating this distinction,
RSLogix 5000 programming software features safety identification icons to
identify the safety task, safety programs, safety routines, and safety components.
In addition, the RSLogix 5000 software uses a safety class attribute that is visible
whenever safety task, safety programs, safety routine, safety tag, or safety
Add-On Instruction properties are displayed.
The controller does not allow writes to safety tag data from external HMI devices
or via message instructions from peer controllers. RSLogix 5000 software can
write safety tags when the Compact GuardLogix controller is safety-unlocked,
does not have a safety task signature, and is operating without safety faults.
The 1768 CompactLogix Controllers User Manual, publicatio
provides information on using 1768 CompactLogix controllers in standard
(non-safety) applications.
HMI Devices
HMI devices can be used with Compact GuardLogix controllers. HMI devices
can access standard tags just as with a standard controller. However, HMI devices
cannot write to safety tags; safety tags are read-only for HMI devices.