Overview
IEC 61158-5-23:2019 - "Industrial communication networks – Fieldbus specifications – Part 5‑23: Application layer service definition – Type 23 elements" defines the application-layer services and Systems Management interface for a Type 23 fieldbus. It specifies the structure and services of the IEC fieldbus application layer (FAL) in conformance with the OSI Basic Reference Model (ISO/IEC 7498‑1) and OSI application layer structure (ISO/IEC 9545). Edition 2.0 (2019) is a technical revision of the 2014 edition and introduces, among other updates, an attribute for Master ID.
Key topics
- Application layer service definition (FAL): Services provided at the boundary between the user and application layer and between application layer and Systems Management.
- ASE and AR structures: Defines Application Service Elements (ASE) and Application Relations (AR) for Type 23, including separate type C and type F element structures.
- Communication models: Describes cyclic models (n:n and 1:n distributed shared memory, push models) and transient models (client/server and push), along with associated service behaviors.
- Cyclic and acyclic data services: Detailed service sets for cyclic transmission, acyclic (transient) transmission, read/write operations, load/set/reset and memory access services.
- Management, synchronization and measurement ASEs: Services for Systems Management, synchronization triggers and measurement reporting.
- Service parameterization: Extensive tables of service parameters (read/write, control cyclic, CT update, vendor commands, statistics, etc.) to ensure consistent implementation and conformance.
- Conformance and terminology: Aligns terms and definitions with ISO/IEC standards and provides conventions for service and class definitions.
- Notable change: Addition of a Master ID attribute to support node identification/management.
Applications / Who uses this standard
- Fieldbus protocol implementers building Type 23 fieldbus stacks (device firmware, gateway software).
- Industrial device manufacturers (PLCs, I/O modules, drives) requiring compliant application-layer behavior.
- System integrators and automation engineers designing deterministic control and real‑time communication systems.
- Test labs and certification bodies validating conformance to IEC fieldbus application services.
- Protocol designers and researchers referencing OSI‑aligned application-layer structures.
Related standards
Keywords: IEC 61158-5-23, fieldbus, application layer service definition, Type 23, FAL, industrial communication networks, ASE, AR, cyclic transmission, acyclic transmission, Master ID.