You MUST give each device on the RS485 bus a unique address. Check the manual of the device on how to do this.
Use lower addresses first (1, 2, ...) because the SmartgridOneController will find them faster!
For each device, it is generally recommended to stick with the factory default baud rate, parity, and stop bits. The SmartgridOneController will scan on those first.
By default, the inverter is set to address 1. This can be changed via the display of the inverter. You can find the procedure in chapter 7.3.2 of the manual.