IEC 61158-6-15:2010

Overview - IEC 61158-6-15:2010 (Type 15 application layer)

IEC 61158-6-15:2010 is the International Electrotechnical Commission specification for the application layer protocol of Type 15 fieldbus systems. It defines the wire representation (transfer syntax) and the externally visible behavior of the service primitives specified in IEC 61158-5-15:2010, in conformance with the OSI Basic Reference Model (ISO/IEC 7498‑1) and the OSI application layer structure (ISO/IEC 9545). Edition 2.0 (2010) replaces the 2007 edition as a technical revision (primarily editorial corrections). This part of the IEC 61158 series targets implementers of industrial communication protocols and device manufacturers needing a standardized application-layer specification for interoperable fieldbus communications.

Key topics and technical requirements

The standard covers detailed protocol elements and requirements, including:

• APDU (Application Protocol Data Unit) formats and overall APDU structure for both client/server and publish/subscribe interaction models.
• Abstract and transfer syntaxes for client/server and publish/subscribe services, including common and service-specific APDU structures.
• Data representation “on the wire”, with encodings for octets, booleans, integers and floating point values.
• Protocol state machines and behavior: FAL protocol machines, FSPM (FAL service protocol machine), ARPM (application relationship protocol machines), and DMPM (DLL mapping protocol machine).
• Publish/subscribe specifics: sub-message structures, APDU interpretation and service identifiers.
• Mapping to lower layers and transports, including guidance for TCP/IP and UDP mappings and the primitives exchanged with the data link layer.
• Service sets and operations commonly used in field devices (read/write registers, coils and file records, device identification, and control/heartbeat mechanisms).
• Conformance and exception handling, including state machine conventions and exception codes.

Practical applications and who uses this standard

IEC 61158-6-15 is used by professionals who need a definitive application-layer protocol specification for Type 15 fieldbus implementations:

• Device and fieldbus interface manufacturers implementing firmware for PLCs, I/O modules, sensors and actuators.
• System integrators and automation engineers designing interoperable control systems and networked industrial devices.
• Software developers building protocol stacks, gateway devices or diagnostic tools for industrial networks.
• Test laboratories and certification bodies verifying conformance to the application layer, state machine behavior and data encodings.

Typical application areas: industrial automation, process control, SCADA connectivity, distributed I/O networks and real‑time machine control where standardized fieldbus application behavior is required.

Related standards

• IEC 61158-5-15 (service primitives for Type 15)
• OSI model references: ISO/IEC 7498-1 and ISO/IEC 9545
• Other parts of IEC 61158 and IEC 61784 series for fieldbus and real-time industrial communication

For authoritative text, purchase or consult IEC publications via the IEC webstore or national standards bodies.