Rockwell Automation AADvance Controller Solutions Handbook - Manual (Page 51)

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Document: 553631
(ICSTT-RM447J_EN_P) Issue: 09:
2-1
An AADvance controller can be configured to manage non-safety up to SIL 3 safety
related system requirements and low demand or high demand fault tolerant
applications.
This chapter describes the different system architectures that can be configured for an
AADvance controller to meet this variety of requirements.
Note: Architectures are independent of I/O module capacity therefore 8 or 16
channel I/O modules can be used.
In This Chapter
SIL2 Architectures .............................................................................................. 2-1
SIL3 Architectures .............................................................................................. 2-6
Planned Certified Configurations .................................................................. 2-11
SIL2 Architectures
SIL2 architectures are recommended for fail-safe low demand applications. All SIL2
architectures can be used for energize or de-energize to trip applications. In any
configuration when a faulty processor or input module is replaced then the previous
fault tolerance level is restored. For example in a fault tolerant input arrangement and
one module is faulty then the system will degrade to 1oo1D, by replacing the faulty
module the configuration is restored to 1oo2D.
Definitions:
Low Demand Mode - in this mode the frequency of demands on the safety-related
system is no greater than twice the proof test interval. Where the proof test interval
refers to how often the safety system is completely tested and ensures it is fully
operational. For the AADvance System the default manual test interval is the value
used to calculate the PFH and PFD values.
High Demand Mode - sometimes called continuous mode, is where the frequency of
demands for operation made on a safety-related system is greater than twice the
manual test interval.
Chapter 2
AADvance System Architectures