Which Comm. Port should be selected in the software GuardScan Monitor (USB type)

The driver has to be installed in your computer first. Once GS1000 is connected with your computer and its power switch is set to on, go to [Control Panel]\ [System]\ [Hardware]\ [Device Manager]\ [Ports (COM & LPT)], you will see “Prolific USB-to-Serial Comm Port (COM number)” showing as the picture below. If it shows “Prolific USB-to-Serial Comm Port (COM 3)”, for example, set “Comm. Port” to COM 3 in the software.