Rockwell Automation AADvance Controller PFH avg and PFD avg Data - Manual (Page 5)

Document: 553847
(ICSTT-RM449_EN_P) Issue 04:
v
Forward Forward Forward Forward
This document contains the PFH
avg
and PFD
avg
Data for the AADvance Controller. It
includes examples on how to calculate the final figures for different controller
configurations. The data supports the recommendations in the AADvance Safety
Manual Doc No: 553630.
Abbreviations Abbreviations Abbreviations Abbreviations
Abbreviation Description
FMPH Failures Per Million Hours
HFT Hardware Fault Tolerance
MTBF Mean Time Between Failures
MTTR Mean time to Repair
MTI Manual Test Interval
PFDavg Probability of Failure on Demand - average
PFDe Probability of Failure on Demand - energized to action
PFDde Probability of Failure on Demand - de-energized to action
PFHe Probability of Failure per Hour - energized to action
PFHde Probability of Failure per Hour - de-energized to action
SFF Safe Failure Fraction
SIF Safety Instrumented Function