Could you specify a scenario in which you want to monitor an RS485 Port?
It depends on a mode which you use. You can select mode at RS232\RS485 tab. You can use LLS mode to monitor liquid level sensor data.
Or you can use TCP mode to send data to a server and then process it the way you want it.
If you use LLS
Select LLS mode, set appropriate baudrate and select an address which is an ID of LLS device. Then in I/O tab you will be able to monitor data going from LLS via RS485 interface.