joro800

Direct connection, terminal is only for test..

I tried everything, no success. listening com port for U90 "get version" command protocol, then send it with virtual terminal to PLC, no answer from STM32. PC drivers recognize mcu, problem is not in drivers...

Yes, i did use it. No solution for now.

Boud rate 9600, 7 data bits, parity even. This PLC have stm32l... mcu, before 6 months i wrote code for virtual com port on stm32f303 without any lib. I don't understand where the problem is in this case, somewhere in protocols maybe.? Мaybe I have to disassemble it and use it for development board...not PLC?

New PLC, installed on machine, programmed with basic functions. I want to reprogram it.

Hi. Usb drivers on WIN 7 32bit system recognize PLC " STM32 virtual com(3)", but that's all, U90 give connection error when trying to check device.?