Devices - FlexControl™ Tuning Knob
The FlexControl installation software installs a USB driver. This driver software installs a new serial COM port to be able to control the FlexControl and to receive commands from it. The FlexControl device is listed in the Windows Device Manager of your computer in the Ports (COM & LPT) section.
The COM Port is listed in brackets after the device name - COM4 in this example.
This port has to be chosen in the COM Port dropdown. Be sure to check also the Use FlexControl Tuning Knob checkbox.