Confirm connection to API in real-time mode

There should be a quick check to make sure that there is a connection to the API in real-time mode. Check networking to wireless LAN, then to wider Internet, then to server, and finally check that the API key actually connects.
This should be an option in Settings.
For an example, my solar panel inverter shows local IP, netmask, gateway, then does a traceroute to its data collection server. 