ISO 17987-8:2019

Overview

ISO 17987-8:2019 defines the electrical physical layer (EPL) for running the Local Interconnect Network (LIN) protocol over vehicle DC powerlines - a profile commonly called DC-LIN. The standard specifies how UART-style LIN bytes are transmitted over the vehicle 12 V and 24 V DC power distribution network using a high‑frequency modulated carrier, without changing LIN higher‑layer behavior. It includes electrical characteristics, modulation methods, carrier injection techniques and conformance test requirements.

Key topics and technical requirements

• EPL scope and compatibility
  • Adds a DC powerline physical layer to the ISO 17987 LIN family while preserving LIN higher layers.
  • Applicable across common vehicle power systems (12 V and 24 V) and supports communication between different powerlines via a coupling capacitor.
• Modulation and data framing
  • Uses a high‑frequency modulated carrier to propagate byte‑oriented UART data (byte fields) over the DC powerline.
  • Byte synchronization via a sync preamble and phase‑based modulation for byte, break and wake‑up fields (byte field, break field, wake‑up signal schemes are specified).
• Supported bit rates
  • 9 615 bit/s, 10 417 bit/s, and 19 230 bit/s (nominal).
• Transmitter / receiver characteristics
  • Electrical transmitter and receiver requirements, line‑in/line‑out interfaces, and monitoring thresholds are specified.
• Timing and tolerance
  • Bit timing, bit sampling, TXD timeouts and inter‑node timing delays are defined for deterministic behavior.
• Electrical parameters & EMC
  • Coupling capacitor requirements, signal injection methods, ESD compliance and line monitoring definitions are covered.
• Conformance and testing
  • Annex B contains a conformance test plan; Annex A gives a peripheral interface example and implementation considerations.
• Normative references
  • Cross‑references to ISO 17987 parts (e.g., Part 4, Part 6) and IEC 61000‑4‑2 (ESD testing).

Practical applications and who uses this standard

• Automotive OEMs and Tier‑1 suppliers: to design LIN networks that reuse vehicle power wiring, reduce harness complexity and enable low‑cost control networks (e.g., door modules, HVAC, body electronics).
• Hardware and IC designers: for designing transceivers, coupling interfaces and MCU peripherals supporting DC‑LIN EPL.
• Test labs and certification bodies: to validate conformance against the Annex B test plan and EMC/ESD requirements.
• Vehicle integrators and system architects: for planning mixed LIN/powerline communication topologies and ensuring interoperability across 12 V and 24 V systems.
• Aftermarket and retrofit suppliers: where powerline-based LIN can simplify installation or add functionality without extra communication harnesses.

Related standards

• ISO 17987 series (Parts 1–7) - LIN architecture, protocol, API and EPL (12 V/24 V)
• ISO 17987-4:2016 (EPL 12 V/24 V)
• ISO 17987-6 (Protocol conformance tests)
• IEC 61000-4-2 (ESD testing)

Keywords: ISO 17987-8, DC-LIN, LIN over DC powerline, Local Interconnect Network, electrical physical layer, automotive powerline communication, 12V, 24V, LIN EPL, conformance test plan.