Hi @ronin48.
The host address is read-only on the ‘Modbus TCP/IP Server’ driver as the server will be running on the Factory IO system. The Modbus clients should then establish connection with the server using that address.
Will your RaspberryPi be acting as a Modbus client, or will it act as the server?
When the PI is the client you should use the ‘Modbus TCP/IP Server’ driver in Factory IO, and point the PI client to the host IP address displayed in Factory IO.
If using the PI as a Modbus server you should use the ‘Modbus TCP/IP Client’ driver in Factory IO. In that case you will be able to edit the ‘Host’ field.