Motorola DTR410

We have been using these radios out of the box successfully for a few years. I recently purchased the cable and downloaded the software. I have hooked up the cable and radio and when I click “read” it says to check the radio connection. When plugged in, the radio says “Device Attached”. I have a RS232 indicator hooked up and it shows both devices are on. When I have used this type of software before you have to tell it what com port to use. I don’t see that anywhere. How does it know which port to use? What am I doing wrong?
Thanks.

P.S. Found the place to set COM port under “Edit” then “Preference”. I see now where in the instructions I have where that is pointed out. Anyway, the software is now reading the device.