13
Master functions
The data bus diagnostic interface is the
master for:
– Drive system CAN continued operation
– MOST ring fault diagnosis
– Data bus system sleep and wake-up
Drive system CAN continued operation
Terminal 15 continued operation for various
control units connected to the drive system
CAN (refer to entry and start authorisation
control unit) is sustained until the data bus
diagnostic interface transmits a command for
termination of continued operation to the
drive system CAN.
MOST ring fault diagnosis
The data bus diagnostic interface is the
diagnosis manager for the MOST bus. This is
responsible for ring fault diagnosis and
transmits the diagnosis data of the control
units in the MOST bus to the data bus
diagnostic interface.
Ring fault diagnosis for the MOST bus is
initiated by way of the final control diagnosis
in the data bus diagnostic interface (refer to
SSP 286 - New Data Bus Systems, Page 41
onwards).
SSP287_007
Sleep and wake-up mode
The data bus diagnostic interface is the
master for sleep and wake-up modes in the
vehicle. When all control units connected to
the convenience CAN indicate "sleep
readiness", the gateway transmits the sleep
command to the CAN bus and the connected
control units switch to sleep status. The sleep
status of the individual control units and bus
systems can be read out in the Audi A8 '03
from the measured value blocks of the data
bus diagnostic interface.
Diagnostic wire
Break in
optical fibre
Diagnostic
connection
Data bus diagnostic
interface
