I am not using Topcon Magnet Field yet (have not installed yet), but using FieldGenius 9/10 on a similar older style data collector Trimble Nomad 900G. So “typically” when using a straight up serial cable such as the Emlid one you and I have, serial port connection is TYPICALLY COM1. My Bluetooth works just fine, so going to stick with it. I purchased the Emlid serial cable as a back up in case of trouble.
I haven’t tried using the serial cable on my Surface Pro yet. I have a serial to USB converter, but I don’t have the need to mess with that yet. I also have some big projects coming up, so like Chasco, I don’t want to mess anything up that is working fine right now.
Wise choice Chasco, I wouldn’t go connecting anything either until you know for certain the pinouts are correct if not using a genuine Emlid cable.