Networking - Audi A4 8W Manual

Networking

Networking
The information electronics control unit 1 J794 is connected to the
data bus diagnostic interface J533 via the infotainment CAN bus in
all infotainment versions. The infotainment CAN bus is a high-speed
bus with a max. data transfer rate of 500 kbit/s.
The following control units may be connected to the
infotainment CAN depending on trim level:
• Information electronics control unit 1 J794
• Control unit in dash panel insert J285
• Control unit for windscreen projection (head-up display) J898
• Selector lever sensors control unit J587
• Data bus diagnostic interface J533
The MMI display J685 and the operating unit E380 are connected to
the information electronics control unit 1 J794 via the Modular
Infotainment Platform (MIB) CAN bus. In addition, the control units
for rear left/right information display and operating unit J648/J649
are subscribers of this bus system. This MIB-CAN is a high-speed bus
with a bandwidth of 500 kbit/s.
If the vehicle is fitted with an additional infotainment control unit
(e.g. Bang & Olufsen Soud System ampifier, TV tuner), the infotain-
ment system is also equipped with a MOST bus. This is also the case
if the vehicle is equipped with a "Top" instrument cluster (9S7) and
Audi virtual cockpit (9S8). The MOST bus is a MOST150 with a data
transfer rate of 150 Mbit/s, where the information electronics
control unit 1 J794 acts both as the system master and diagnostics
master for the MOST bus.
The following control units may also be connected to the MOST bus
depending on trim level:
• Information electronics control unit 1 J794
• Digital sound package control unit J525
• TV tuner R78
• Control unit in dash panel insert J285
!
Note
A special networking case is the equipment variant MMI Radio plus (i8E) in combination with the "Top" instrument cluster
with 7" colour display (9S7). In this case, the instrument cluster does not have an interface to the MOST bus.
32
Image transfer
The displays for the control unit in dash panel insert J285 are
transferred from the information electronics control unit 1 J794 as
follows:
1. Audi virtual cockpit:
• LVDS: The large navigation map and the detailed intersection
maps use the LVDS connection as a transmission pathway.
• MOST bus: All other content, such as list menus or covers
and software updates of dash panel insert J285, is received
via the MOST bus.
• Infotainment CAN: All other content is communicated via
the infotainment CAN.
2. "Top" instrument cluster:
• MOST bus: the navigation data (incl. map) and software
updates for J285 are transmitted via the MOST bus.
• Infotainment CAN: All other content is communicated via
the infotainment CAN.
• The "Top" instrument cluster does not have an LVDS inter-
face.
3. "Medium" instrument cluster:
• All content is communicated via the infotainment CAN.
• The "Medium" instrument cluster does not have an LVDS
interface or a MOST bus interface.
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