Is your plotter connected using a or a USB-to-Serial adapter cable ? Share public link

: Go to Device Manager > Ports > Right-click your COM Port > Properties > Port Settings > Advanced . Lower the Receive Buffer and Transmit Buffer sliders to their lowest settings. Ensure your machine is properly grounded to eliminate static buildup. Error: "Cannot Open Port" in Software

I can give you step-by-step instructions tailored to your specific setup. Share public link