Embraco Fullmotion CF10C - Page 39

CHAPTER 4. OPERATION 34
VCC



CN 203 pinout:
PIN 1 – Signal from Thermostat
PIN 2 – Thermostat GND
3
2
1
VCC
Inverter RX
Inverter TX
VCC
CN 204 pinout:
PIN 1 – Signal from Thermostat
PIN 2 – Thermostat GND
PIN 3 – Signal toThermostat
Collector current
range: 1 mA to 2 mA
CN 204

1
3
2
Thermostat TX
Thermostat RX
VCC
Thermostat TX
Inverter board
Figure 4.4: Electrical schematic of serial communication
To guarantee the correct functionality of serial communication, the signal to be sent
to the inverter must be according to the following values.
Signal specications
Voltage range -5 V to +15 V
TRUE state -5 V to +0.7 V
FALSE state +4.5 V to +15 V
Maximum current 2 mA @ 15 V
-5V
0.7V
4.5V
15V
TRUE state
Indenite state
FALSE state
↑
Start
bit
Data bits
Stop
bit
0
1 2
3
4
5
6 7
FALSE
TRUE
FALSE FALSE
TRUE TRUE TRUE
FALSE FALSE
TRUE
Time
Amplitude [V]
Example: 39h sent to inverter
The identication byte (1st byte), is used for command synchronization. Aſter in-
verter identies a valid A5h, it starts to read the next 4 bytes. Aſter reading, a re-