Many USB devices actually appear on your PC as an RS232 comport, but the provided driver needs to be installed. Once the driver is installed, you can identify the comport number assigned by the operating system by opening the terminal emulator under the tools menu. Click on the Serial Port drop down menu and all available serial ports will appear. You can then test communications with the USB device with the terminal emulator.
Support for devices that use the native USB protocols is coming soon. Contact Green Eyes for a status report.