ISA-TR84.06

Part 6 of ISA-84: "Safety Fieldbus Design Considerations for Process Industry Sector Applications" (ISA–TR84.00.06)

Safety Fieldbuses are currently being used in various industrial sectors, such as automotive and machinery, but they have only recently been introduced within the process sector for safety instrumented systems (SISs). ISA84 committee members are concerned that generic Fieldbuses may be incorrectly implemented in SIS applications. Consequently, the ISA84 committee formed Working Group 1 (ISA84 WG1) to develop guidance on the implementation of Safety Fieldbuses as part of an SIS for communicating between a safety logic solver and field devices.

This technical report addresses the use of Fieldbus for multi-drop digital network communication for implementation of Safety Instrumental Function (SIF) within a safety logic solver designed and managed in compliance with ANSI/ISA-84.00.01-2004. If the reader chooses to implement the safety logic in the Fieldbus segment only, the fieldbus and any instruments executing the safety logic should be evaluated as a logic solver under the requirements of ANSI/ISA-84.00.01-2004. This technical report does not address implementation of the SIF logic within the Fieldbus segment.

Scope

This technical report:

provides guidance on implementing Safety Fieldbus protocols and devices in safety instrumented systems in the process industries
recommends additional considerations and practices for the implementation of Safety Fieldbus that are not currently included in ANSI/ISA-84.00.01-2004.