This document discusses a safety certified modular configuration that achieves SIL3 certification in a single module. It has an internal duplex channel architecture with comparators and diagnostic functions in the CPU and IOM. Over 99% diagnostic coverage is achieved through comparison and over 99.5% with self-diagnostics in the CPU and IOM. There is also a redundant option that provides a PFDavg of 10^-8 at 1 year with increased system availability of 99.999862%.

1. Safety in Single SIL3
is SIL3 certified in a single modular configuration.
CPU & IOM have internal duplex channel architecture with
comparator and diagnostic functions.
Simple Single SIL3
Input Circuit CPU Output Circuit
Comparator Comparator Comparator
+ Diagnosis + Diagnosis + Diagnosis
Input Circuit CPU Circuit Output Circuit
Over 99% of Diagnostic Coverage is achieved by comparison.
With self-diagnostics in CPU & IOM, DC reaches over 99.5%.
Copyright © Yokogawa Electric Corporation
E-2008-0501-D Safety and Availability Safety and Availability Page 2
2008/05

2. VMR: Redundant Option
Simple Single SIL3
PFDave: 10^-8
Input Circuit CPU Circuit Output Circuit
@T:1year
Comparator Comparator Comparator (Di-Do Estimate @FMEDA)
+ Diagnosis + Diagnosis + Diagnosis
Input Circuit CPU Circuit Output Circuit
System Availability
99.999862%
Redundant Option (Estimate @model)
Input CPU Output
Circuit, MPU MPU, memory Circuit, MPU
Circuit, MPU MPU, memory Circuit, MPU
Circuit, MPU MPU, memory Circuit, MPU
Circuit, MPU MPU, memory Circuit, MPU
Keeping SIL3
Copyright © Yokogawa Electric Corporation
E-2008-0501-D Safety and Availability Safety and Availability Page 3
2008/05