Rockwell Automation Publication 1734-UM013J-EN-P - July 2014 181
Appendix D
Safety Data
This appendix lists calculated values for probability of failure on demand (PFD), 
probability of failure per hour (PFH), and mean time to failure (MTTF). PFD 
and PFH calculations comply with IEC61508, edition 2, 2010.
Calculated values of probability of failure on demand and probability of failure 
per hour appear in the table and must be calculated for the devices within the 
system to comply with the SIL level required for application.
Users must be responsible for following the requirements of ISO 13849-1:2008, 
to assess performance levels in their safety system.
Within the proof test interval, every I/O module must be functionally tested by 
individually toggling each input point and verifying that it is detected by the 
controller. 
Additionally, each output point must be individually toggled by the controller 
and user-verified that the output point changes state.
For more information, refer to these publications.
Resource Description
GuardLogix 5570 Controller Systems Safety 
Reference Manual, publication 
1756-RM099
Provides information on safety application requirements for GuardLogix 
5570 controllers in Studio 5000 Logix Designer projects.
GuardLogix Controller Systems Safety 
Reference Manual, publication 
1756-RM093
Provides information on safety application requirements for GuardLogix 
5560 and 5570 controllers in RSLogix 5000 projects.