Haier H2SM Series Service Manual page 14

1. Definition of chip tubes' pins
Chips are used in this manual and their pins are defined as follows:
Chip's Pins
GND GND
XIN XIN
XOUT XOUT
TEST GND
VDD +5V
P21 Alarm light
(to be connected with pull resistance)
reuse for self-checking/contracting
P22 Serial communication output
(to be connected with pull resistance)
RESET Reset
P20 4-way valve A
P00 4-way valve B
P01 High air flowrate
P02 Mid air flowrate
P03 Low air flowrate
P04 Compressor B
2. Communication format
Note: This communication format is compatible with 3 models, i.e., double-compressor one-drive-two
without converter, single-compressor one-drive-two without converter and one-drive-two with
converter.
2.1. Sequence of communication
Communication begins 2 seconds after the power supply inputs. The indoor unit first gives out a
signal and outputs the LO which remains at 5 ms, then changes to receive signal. If it fails to
receive signal 2 seconds after the signal is given out, it will give out a signal once again. After the
signal is received, it will give out a signal once more 10 ms later. When the indoor unit is waiting
for the signal input, the signal output is HI. If the indoor unit fails to receive signals in normal
condition in times (20 seconds) after the previous signal has been received, the transmission is
abnormal. But time shortage and being halted are not of abnormal transmission. Communication is
carried out when a correct HDA signal is received. After the signal has been received, the
communication data is compared with the inverter data. When incorrect, all the data will be given
up. The outdoor unit waits to receive signal HEADER HDR(81H) from the indoor unit after the
power supply inputs. After the signal has been received, the communication data is compared with
the inverter data. When incorrect, all the data will be given up.
Definition of Function
Air Conditioner
Chip's Definition of Function
Pins
P37AIN5 CTA signal input
P36AIN4 CTB signal input
P35AIN3 tube temperature A
P34AIN2 tube temperature B
P33 AIN1 Outdoor ambient temperature
P32 AIN0 P32 P31
0
0
1
P31
1
P30 EEPROM--SCL
P12 EEPROM--SDA
P11 -INT1 Communication input A
P10 -INTO Communication input B
P07 Communication output A
P06 Communication output B
P05 Compressor A
10
Edition:2006/1/10
Model selection
0 Model 1
1 Model 2
0 Model 3
1 Model 4