MySerial1.DataTerminalReady=True
MySerial1.Reset
Not sure if that will help, it asserts DTR (whereas the docs say the .DTR property turns on DTR flow control, which I’ve never seen used by anything (RTS/CTS yes but not DTR/DSR). Anyway I know that setting .DataTerminalReady property to True or False will in fact turn on and off the DTR line. I’m using a GM-FTDI2-LED-C (Gearmo) USB-RS-232 adapter in Windows 11 under VMWare Fusion and compiled using Xojo 2023R4.