ISO 17987-2:2016

Overview

ISO 17987-2:2016 specifies the transport protocol and network layer services for Local Interconnect Network (LIN)-based vehicle systems. The standard defines an unconfirmed communication transport layer tailored to LIN sub-buses and provides a standardized API for transporting application-layer messages - including both normal and diagnostic communication messages. It enables diagnostic functionality on LIN clusters while targeting clusters with more powerful LIN nodes and aims to minimize load on the LIN master node.

Key technical topics and requirements

• Transport protocol primitives and PDUs: Defines protocol data unit (PDU) types used for LIN transport - Single Frame (SF), First Frame (FF) and Consecutive Frame (CF) - and specifies the N_PCI control information fields that identify them.
• Network layer services and API: Standardized service primitives (e.g., N_USData.request, N_USData.confirm, N_USData.indication) for higher-layer integration and consistent service interfaces.
• Mapping to data link layer: Rules for mapping transport PDUs onto LIN data link services (L_Data.request/confirm/indication) and the PDU structure used on LIN frames.
• Timing, error handling and timeouts: Network-layer timing constraints, timeout handling, error recovery and unexpected-PDU behavior to support reliable multi-frame transfers.
• Diagnostic communication support: Transport-layer handling optimized for diagnostic messages (response pending, diagnostic classes, slave/master scheduling) so diagnostics can be performed via LIN or mirrored from a backbone bus.
• Network management: Node wake-up/sleep behaviors, communication state diagrams, and network management requirements for LIN clusters.
• Node capability and plug-and-play: Specification of LIN Node Capability Language (NCL) and Node Capability File (NCF) formats to describe node features, signals, frames and diagnostics for cluster design and debugging.

Practical applications and who uses ISO 17987-2:2016

• Vehicle OEMs and system architects designing LIN sub-bus clusters that require diagnostic access or application-layer transport services.
• ECU/LIN node firmware developers implementing transport and network layer stacks for slaves and masters.
• Diagnostic tool vendors and integration engineers who need consistent APIs and PDU mappings for LIN-based diagnostics.
• Tier‑1 suppliers building clusters that mirror backbone diagnostic capabilities (e.g., CAN) on LIN sub-buses while minimizing master CPU load.
• Test, validation and calibration teams using NCF/NCL descriptions for plug-and-play cluster configuration and debugging.

Related standards

• ISO 14229-2 (UDS service primitives) - referenced for standardized service primitive interface.
• ISO 15765-2 (CAN transport) - messages and PDUs are aligned to enable consistent diagnostic behavior across backbone and LIN sub-buses.

ISO 17987-2:2016 is essential for reliable multi-frame transport and diagnostic support on LIN networks, enabling consistent diagnostics and efficient network-layer implementations for modern vehicle architectures.