CD changer TOYOTA CAMRY 2000 Service Owner's Manual

GENERAL 1999 FEATURES
160GE01
Radio and Cassette DeckCommunication BusCD Changer
Physical Address : 190
Logical Address : 11 (Mode Control)
25 (Command Switch)
60 (Radio Tuner)
61 (Cassette Deck)Physical Address: 240
Logical Address: 43 10
2. Communication Outline
In the audio system that uses AVC-LAN, audio units such as a cassette deck or a CD changer are connected
by a communication bus that establishes communication via serial data signals.
In this system, addresses are used to identify the units with which to establish communication. The addresses
can be broadly divided into two types: the physical address that is assigned to each audio unit such as a cas-
sette deck, CD changer, etc.; and the logical address that is assigned to the function that each unit provides,
such as the radio function or the cassette function. The physical addresses are represented by 3-digit numbers
and the logical addresses are represented by 2-digit numbers.
The signals that are exchanged between the units are the unit's control signal, display data, audio signal, etc.,
which have been rendered into serial data. The configuration of the 4 signals indicated below, which are ren-
dered into serial data and transmitted to the each unit, has been established as a uniform AVC-LAN standard.
Audio Signal
Video Signal
Display Data
Signal Communication Software
The illustration below shows an example of an audio system configuration using AVC-LAN.
3. Operation
System Registration
An audio system that uses AVC-LAN performs a registration process to verify the audio units that comprise
the system.
When the ignition switch is turned to the ACC position, the audio units that comprise the system transmit
the logic address in the units, and the physical address is transmitted by the mode control portion that is
integrated in the smallest audio unit (head unit). By receiving these addresses, the mode control portion veri-
fies the units that comprise the system.
By performing this process, all functions can be controlled regardless of the combination of the units that
comprise the system.

1
GENERAL 1999 FEATURES
160GE02
160GE03
MUTE
Sound
VOL
74
ICIC
Cassette
61Radio
60ICCD
Changer
43
Power Amplifier
Power Supply
Control
Mode ControlCommand
SwitchVolume Cassette Radio
Fig. 1
CD Changer
OFF
CD
Radio
CD
Play Notice
Output ON Request
Output ON Verification
Output OFF Verification
Output ON VerificationOutput ON Request Amplifier Power
Supply ON
Power On Notice Output ON Verification Output ON Instruction
Output ON Instruction
Output ON Instruction Output OFF Instruction
Radio ONCD OFFCD ON
AMFM
Fig. 2
(Shielded)
(Press Switch)
(Press Switch)
11
Switching the System
An audio system that uses AVC-LAN consists of audio units that are connected in parallel as described in
Fig. 1. Each of the audio units has a switch to connect the unit to the communication bus.
To control the audio units in accordance with the system to be operated, the mode control portion transmits
output ON and output OFF instructions. In accordance with the instruction signals transmitted by the mode
control portion, the units turn their switches ON or OFF to switch the operating unit and system. Fig. 2 shows
an example of a signal exchange that takes place between the mode control unit and each audio unit during
the switching of the system.