Road vehicles — Interchange of digital information on electrical connections between towing and towed vehicles — Part 1: Physical and data-link layers

This document describes the data link layer (DLL) and physical layer (PHY) for the two CAN-based network interfaces specified in the 11992-series.

The DLL sub-clauses are composed of:

— DLL protocol entity requirements;

— DLL device interface requirements; and

— DLL network system requirements.

Normally, the physical signalling sub-layer is implemented in the CAN protocol controller. The physical medium attachment sub-layer is normally implemented in the CAN transceiver or the System Base Chip (SBC). Optionally, it can comprise also additional protection circuitry. The media-dependent sub-layer comprises the connectors and the cabling.

The physical signalling (PS) sub-clauses are composed of:

— PS entity requirements;

— PS device interface requirements; and

— PS network system requirements.

The physical medium attachment (PMA) sub-clauses are composed of:

— PMA protocol entity requirements; and

— PMA device interface requirements.

The physical medium dependent (PMD) sub-clauses are composed of:

— PMD entity requirements;

— PMD device interface requirements; and

— PMD network system requirements.