Huawei Backup Box-B0 Quick Manual page 11

Connecting Signal Cables on the Inverter Side
3.8
SUN2000-(2KTL-6KTL)-L1
COM Port Pin Definitions
No. Label Definition Description
5 GND GND
8 DI2 Digital
input
signal 2+
10
X4
COM port (COM)
Connects to the GND of the DI2 port.
Connects to the positive terminal of DI2
and functions as the port for the Backup
Box to send feedback signals.
Inverter AC