Toyota AVENSIS 2000 Supplement Manual page 709

BE–18
7. OUTLINE OF AVC–LAN
(a) What is AVC–LAN?
AVC–LAN is the abbreviation, which stands for Audio Visual Communication–Local Area Network.
This is a unified standard co–developed by 6 audio manufactures associated with Toyota Motor Corpo-
ration.
The Unified standard covers signals, such as audio signal, visual signal, signal for switch indication
and communication signal.
(b) Objectives
Recently the car audio system has been rapidly developed and functions have been changed drasti-
cally. The conventional system has been switched to the multi–media type such as a navigation sys-
tem. At the same time the level of customers needs to audio system has been upgraded. This lies be-
hind this standardization.
The concrete objectives are explained below.
(1) When products by different manufactures were combined together, there used to be a case that
malfunction occurred such as sound did not come out. This problem has been resolved by stan-
dardization of signals.
(2) Various types of after market products have been able to add or replace freely.
(3) Because of the above (2), each manufacture has become able to concentrate on developing
products in their strongest field. This has enabled many types of products provided inexpensive-
ly.
(4) Conventionally, a new product developed by a manufacture could not be used due to a lack of
compatibility with other manufactures products. Because of this new standard, users can enjoy
compatible products provided for them timely.
The above descriptions are the objectives to introduce AVC–LAN. By this standardization, development of
new products will no longer cause systematic errors. Thus, this is very effective standard for a product in the
future.
HINT:
S
When +B short or GND short is detected in AVC–LAN circuit, communication stops. Accordingly the
audio system does not function normally.
S
When audio system is not equipped with a navigation system, audio head unit is the master unit. (When
audio system is equipped with a navigation system, navigation ECU is the master unit.)
S
The car audio system using AVC–LAN circuit has a diagnosis function.
S
Each product has its own specified numbers called physical address. Numbers are also allotted to
each function in one product, which are called logical address.
AVENSIS/CORONA SUP (RM781E)
BODY ELECTRICAL
Radio Receiver Assembly
– AUDIO SYSTEM
Multi Display
I12412