Identifying available ports in MAX

Hi, I'm new to MAX/MSP and this is my first time posting.
I'm trying to send data from my arduino to max, and I need to identify which port the arduino is connected to. All the videos online show using a print object connected to a serial object to print which ports are available, with the output of the print connected to the input of the serial object. But my print object only has an input and when I connect it to the serial it doesn't show anything. Any ideas how I can fix this? Or try another way to see available ports, would be really appreciated.
Thanks