are you using an rs232 port on your PC? or a usb to RS232 adaptor?
If you are using an adaptor, verify which comport you are on. If the Panel Builder software recognizes the adaptor, it should give you an option for the point to point on that com
i.e DF1 point to point --- internal com 3
This is in addition to DF1 point to point RSlinxAB_DF1