Verify USB driver installation in Windows
Once the GMC-320 Plus is connected to a computer, from the device manger, you should
see which COM port is assigned to the GMC-320 Plus. See the example below. Windows
assigned COM3 to the GMC-320 Plus unit in this example.
For the data viewer or the data logger software, selecting COM5 will establish the connection
to the GMC-320 Plus Geiger counter for the above example