IEC 61784-3-8 pdf download – Industrial communication networks – Profiles – Part 3-8: Functional safety fieldbuses – Additional specifications for CPF 8
1 Scope
This part of the lEC 61784-3 series specifies a safety communication layer (services andprotocol) based on CPF 8 of lEC 61784-1 and lEC61158 Type 18. It identifies the principlesfor functional safety communications defined in lEC 61784-3 that are relevant for this safetycommunication layer.
NOTE 1 It does not cover electrical safety and intrinsic safety aspects，Electrical safety relates to hazards suchas electrical shock. lntrinsic satety relates to hazards associated with potentially explosive atmospheres.
This part 1 defines mechanisms for the transmission of safety-relevant messages amongparticipants within a distributed network using fieldbus technology in accordance with therequirements of lEC 61508 series2 for functional safety.These mechanisms may be used invarious industrial applications such as process control，manufacturing automation andmachinery.
This part provides guidelines for both developers and assessors of compliant devices andsystems.
NOTE 2The resulting SlIL claim of a system depends on the implementation of the selected functional safetycommunication profile within this system m implementation of a function al safety communication profile according tothis part in a standard device is not sufficient to qualify it as a safety dewice.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies.For undated references,the latest editionof the referenced document (including any amendments) applies.
IEC 60204-1，Safety of machinery – Electrical equipment of machines – Part 1: Generalrequirements
IEC 61131-2，Programmable controllers – Part 2: Equipment requirements and tests
IEC 61158(all parts), Industrial communication networks – Fieldbus specifications
IEC 61158-2，Industrial communication networks – Fieldbus specifications – Part 2: Physicallayer specification and service definition
IEC 61158-3-18，Industrial communication networks – Fieldbus specifications – Part 3-18:;Data-link layer service definition – Type 18 elements
IEC 61158-4-18,Industrial communication networks – Fieldbus specifications – Part 4-18:Data-link layer protocol specification – Type 18 elements
IEC 61158-5-18,Industrial communication networks – Fieldbus specifications – Part 5-18:Application layer service definition – Type 18 elements
IEC 61158-6-18，Industrial communication networks – Fieldbus specifications – Part 6-18:Application layer protocol specification – Type 18 elements
IEC 61326-3-1，Electrical equipment for measurement， control and laboratory use – EMCrequirements – Part 3-1: lmmunity requirements for safety-related systems and for equipmentintended to perform safety related functions (functional safety) -General industrialapplications
IEC 61326-3-2，Electrical equipment for measurement,control and laboratory use – EMCrequirements – Part 3-2: Immunity requirements for safety-related systems and for equipmentintended to perform safety related functions(functional safety) – industrial applications withspecified electromagnetic environment
IEC 61508 (all parts),Functional safety of electrical/electronic/programmable electronicsafety-related systems
IEC 61511 (all parts)，Functional safety – Safety instrumented systems for the processindusfry sector
IEC 61784-1，Industrial communication networks – Profiles – Part 1: Fieldbus profiles
IEC61784-3:20103 Industrial communication networks – Profiles – Part 3:Functional safetyfieldbuses – General rules and profile definitions
lEC 62061,Safety of machinery – Functional safety of safety-related electrical, electronic andprogrammable electronic confrol systems
3Terms, definitions, symbols, abbreviated terms and conventions
3.1Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1Common terms and definitions
3.1.1.1
availability
probability for an automated system that for a given period of time there are no unsatisfactorysystem conditions such as loss of production
3.1.1.2
black channel
communication channel without available evidence of design or validation according toIEC 61508
3.1.1.3
communication channel
logical connection between two end-points within a communication system
3.1.1.4
communication system
arrangement of hardware,software and propagation media to allow the transfer of messages(IsoriEc 7498 application layer) from one application to another
3.1.1.5
connection
logical binding between two application objects within the same or different devices
3.1.1.6
cyclic Redundancy Check (cRC)
NOTE 1 Terms ‘cRC code” and “CRC signature” , and labels such as CRC1,CRC2,may also be used in thisstandard to reter to the redundant data.
NOTE 2 See also[32].[33]4.
3.1.1.7
error
discrepancy between a computed,observed or measured value or condition and the true,specified or theoretically correct value or condition
[IEC 61508-4:20105],[IEC 61158]
NOTE 1 Errors may be due to design mistakes within hardwarelsoftware and/or corrupted information due toalectromagnetic interference andIor other effects.
NOTE 2 Errors do not necessarily result in a failure or a faulr.3.1.1.8
failure
termination of the ability of a functional unit to perform a required function or operation of afunctional unit in any way other than as required
NOTE 1 The cefinition in lEC 61508-4 is the same, with additionall notes.
[IEC 61508-4:2010, modified]. [ISO/IEC 2382-14.01.11, modified]
NOTE 2 Failure may be due to an error (for example，problem with hardware/software design or messagedisruptionj-
3.1.1.9fault
abnormal condition that may cause a reduction in, or loss of, the capability of a functional unitto perform a required function
NOTE IEV 191-05-01 defines “fault’ as a state characterized by the inabillity to perform a required function,excluding the inablity during preventive maintenance or other planned actions, or due to lack of external resources.[IEC61508-4:2010, modified],[ISO/lEC 2382-14.01.10, modified]
3.1.1.10
fieldbus
communication system based on serial data transfer and used in industrial automation orprocess control applications
IEC 61784-3-8 pdf download – Industrial communication networks – Profiles – Part 3-8: Functional safety fieldbuses – Additional specifications for CPF 8
