HAC-18
< SYSTEM DESCRIPTION >
[AUTOMATIC AIR CONDITIONER]
SYSTEM
A small network exists between the A/C auto amp., the mode door motor, the air mix door motor and the intake
door motor. The A/C auto amp. and motors are connected by data transmission lines and motor power supply
lines. The LAN network is built through the ground circuits of each door motor.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the A/C auto amp. and each door motor.
The following functions are contained in LCUs built into the mode door motor, the air mix door motors and the
intake door motor.
• Address
• Motor opening angle signals
• Data transmission
• Motor stop and drive decision
• Opening angle sensor (PBR function)
• Comparison
• Decision (A/C auto amp. indicated value and motor opening angle comparison)
Operation
The A/C auto amp. receives data from each of the sensors. The A/C auto amp. sends mode door, the air mix
door and the intake door opening angle data to the mode door motor LCU, the air mix door motor LCUs and
the intake door motor LCU.
The mode door motor, the air mix door motors and the intake door motor read their respective signals accord-
ing to the address signal. Opening angle indication signals received from the A/C auto amp. and each of the
motor position sensors is compared by the LCUs in each door motor with the existing decision and opening
angles. Next, HOT/COLD, DEF/VENT, OPEN/SHUT or FRE/REC operation is selected. The new selection
data is returned to the A/C auto amp.
Transmission Data and Transmission Order
A/C auto amp. data is transmitted consecutively to each of the door motors following the form as shown in the
figure below.
START:
• Initial compulsory signal is sent to each of the door motors.
ADDRESS:
• Data sent from the A/C auto amp. is selected according to data-based decisions made by the mode door
motor, the air mix door motors and the intake door motor.
• If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data has no error, door con-
trol begins.
• If an error exists, the received data is rejected and the corrected data received. Finally, door control is based
upon the corrected opening angle data.
OPENING ANGLE:
• Data that shows the indicated door opening angle of each door motor.
JMIIA0748GB
JMIIA0749GB