You can check for a network connection using the "Insert From URL" script step to insert a web page into a text field.
If you try to insert something like google.com and don't get a result, then you know it's not connected to the internet.
Get(SystemIPAddress) may return something even if you are not connected to the internet.
I want to check if the device is conected to the FM Server.
I just tried to open another simple file (Test_Remote) from the remote host, if Get(LastError) = 0, then the file could be opened, which means the FM server is available and if Get(LastError) = 802, then it means the remote file is not available and hence stays in the local file.