If you are unable to discover fresco units, or fresco units are not showing as online within Fresco Studio, there may be a basic network connectivity issue.
Check the link light on Ethernet connected Fresco unit. On back of unit where Ethernet port is, a green and amber led should be on/flashing.
Check IP address settings, If using Static IP, you must be on the same subnet (i.e. 192.168.1.100 and the Fresco is 192.168.1.5 with subnet 255.255.255.0)
If using Dynamic IP, check if an ip address is assigned to the Fresco, it should be display on the About screen.
Ping the Fresco controller i.e. use command-line tool 'ping <ip-address>' where ip address is the ip of the connected device.
Verify the controller id is 1 for the Fresco, only Fresco units with a controller id of 1 should be connected by Ethernet. All other units can be accessed by the FCN 485 bus.
See also article regarding devices not discovering or file transfer not completing.