Below is a picture of my inverter screen and yours should be similar. The important things to note are:
1. Pac[W] is greater than 0 (this is how much power the inverter is producing right now so it will be 0 at night)
2. P_OK: X/X where X is the number of solar panels you have on your roof (in the picture below it means that 15 out of 15 of my solar panels are working)
3. <S_OK> (this means that the inverter is connected to the internet)
If you don't see the numbers above on the first screen, something could be wrong.