How to test CC4 PRO C Port communication

CANBUS not working: How to check if the main unit C area serial port is transmitting and receiving data normally? The data interaction between CANBUS and the main unit is completed through the TX and RX wires in the Carea. If the CANBUS settings, wiring connections, and CANBUS model are all correct but the CANBUS function still does notwork, the problem is most likely with the main unit itself. Troubleshooting steps: The white socket should remain hanging and no cables should be inserted.
Open the CANBUS settings, and select the CANBUS option shown in the diagram (Note: this setting is only for testing whether the serial port works normally). Open the log record, and codes will appear on the screen:
If both red and green sections show data fluctuations → the main unit serial port is normal. If only the red section shows data fluctuations → the main unit serial port is abnormal, and the main unit is faulty.