In your CIMPLICITY project configuration, device and point data are protocol dependent. You cannot delete a port then re-add it using another protocol if device and point data for the original port still exist.
To change a port's protocol:
Export the point data for the port using the Import/Export utility if you plan to re-use the same point data.
Delete the point data for the port.
Delete the device data for the port.
Delete the port.
Create the port with the new protocol.
Define the devices for the port.
If you exported the point data, then use the Import/Export utility to import the point data. Otherwise, define new points.
Other port configuration.