To connect the inverter to Internet via Ethernet cable, use an RJ45 cable and connect it from the "ETH" port of the inverter to your router. Check that the LEDs are blinking on the "ETH" port of the inverter.
If this is not the case, your cable or router must be defective. Please check with your customer the cable used and the router.
If the LEDs on the "ETH" port of the inverter are blinking, the communication between the inverter and the router has started.