Please excuse me if this is already a topic, searching only brought up articles with no relevance. Even Google seems to be lacking. I'm wondering if there is a way to identify a COM port on my PC without having to "just plug something in and see if it works". Little background, this PC and about 12 others are running automated test equipment, and we install 1 or 2, dual serial PCIE cards to communicate with all the test equipment (don't ask why we're not using USB, we do on newer equipment). Cards and drivers are installed and listed in Device Manager as COM 1 - COM 5, no problem. Issue arises when we want to mark the COM port numbers on the back of the PC. There has to be a stupid dongle or something that allows you to activate the ports and see which one is which. We're even willing to build a device from scratch and write a Labview program to do it, but there must be something we can buy.