To upgrade the firmware, you will need to set up an environment as below.

1. Connect the USB cable's Type A connector to a USB port on your computer, at the other end of the USB cable, connect the USB Type B connector to the USB Type B port in the Port 1 KVM section.

2.

a.When the environment is prepared, turn on the KVM, invoke OSD.

Key in: [U] [P] [G] [R] [A] [D] [E], Press [Enter] (The front panel LEDs flash to indicate the upgrade has started)

or 

b.Press and hold the Port 1 selection pushbutton. While you are holding the button, connect the power adapter to the CS1922M / CS1924M to enter Firmware Upgrade Mode.

3. Run the firmware upgrade utility to perform upgrading. When it is finished, KVM will restart automatically. 

For details, please refer to the below video.