Full Description

ISO 20794-4:2020 specifies the CXPI data link layer and the CXPI physical layer.

The DLL is based on:

priority-based CXPI network access;

non-destructive content-based arbitration;

broadcast frame transfer and acceptance filtering; and

node related error detection and error signalling.

The CXPI physical layer (PHY) requirements comprise of:

physical signalling (PS) sub-layer, which specifies the requirements of the clock generation function, the encoding and decoding of CXPI frames, and bit-wise collision resolution logic;

physical media attachment (PMA) sub-layer, which specifies the requirements of the signal shaping waveform logic;

physical media dependent (PMD) sub-layer, which specifies the requirements of the CXPI network termination, electrostatic discharge protection, etc., and device connector requirements; and

physical media (PM), which specifies the requirements of the CXPI network cable/wiring harness.