| Problem | Likely Cause | Solution | | :--- | :--- | :--- | | | Driver signature enforcement | Disable Secure Boot or temporarily disable driver signature enforcement (Shift + Restart → Troubleshoot → Startup Settings → Disable driver signature enforcement). | | COM port number > 10 | Windows assigns high COM port | Manually change to lower COM port (e.g., COM3) in Device Manager → Port Settings → Advanced. | | Download fails mid-way | USB cable too long or poor quality | Use shielded USB cable < 3 meters. Avoid USB hubs. | | Driver conflicts with other USB devices | Multiple CDC drivers | Uninstall other COM port drivers temporarily or reinstall MCGS driver last. | | HMI not detected at all | Wrong USB mode on HMI | Some MCGS HMIs require enabling USB Download Mode in the HMI’s system settings (check HMI manual). |
Alternatively, access the HMI's internal calibration/system menu during boot-up and select "USB Download Mode" if available. 4. Software Com Port Matching If the driver installs as a USB-to-Serial virtual COM port: mcgs hmi usb driver
Which (e.g., Windows 10, Windows 11) is your engineering PC running? | Problem | Likely Cause | Solution |
Navigate to the top menu and click on or Download Settings . Locate the Communication Method or Link Type dropdown menu. Select USB (instead of COM port or Network/LAN). Avoid USB hubs
: Download the latest version of MCGS Pro configuration software. The integrated setup wizard automatically updates the USB drivers.
If you need a standalone driver or an updated version for newer Windows operating systems, always download it directly from the official Kunlun Tongtai website or your authorized hardware distributor. Avoid third-party driver update sites to protect your engineering PC from malware. Step-by-Step Guide to Installing the MCGS USB Driver
However, the MCGS HMI does not use a standard Windows USB class driver (like a mouse or keyboard). Instead, it uses a proprietary or a dedicated download protocol driver . Without this specific driver, your PC will see the HMI as an "Unknown Device" in Device Manager.