Connect your printer via USB and run the TSC Diagnostic Tool.

Select the "Command Tool" or "Firmware Update" tab in the utility and point it to the extracted file.

Ensure your printer is connected to a stable power source during the update. A power interruption while flashing firmware can "brick" the device, making it unusable. Firmware V3.1.1 for SCALANCE SC622-2C, SC626- ... - Support

Firmware for these devices is usually flashed using the Diagnostic Tool (DiagTool) available on the TSC Printers Support site. Common Reasons for This Update

This type of firmware is commonly associated with desktop thermal label printers like the TSC DA210 or the TSC TE244 .