Huawei SUN2000-25KTL - Communication Card and Inverter Linking; Single Inverter Communication Setup; Multiple Inverter Daisy Chain

Communication Card Settings
Single Inverter
Terminal Resistor-off
Multiple Inverters
If multiple SUN2000s are used, connect all the SUN2000s in daisy chain mode over an RS485 communications cable.
Pin 2 & 4 of Inv-1 is connected to Pin 1 & 3 of next inverter in Daisy Chain.
When two or more inverters are in parallel communication, the terminal resistor should be switched on or else, it may cause
communication interruption.
NOTE: The above details are mentioned in the Installation & Operation Manual
for SUN2000-(33KTL, 36KTL, 40KTL,55KTL, 60KTL)
or Installation & Operation Manual for SUN2000-(25KTL, 30KTL)