UART port works on WINDOWS 10 using Minicom, Device Monitoring Studio, etc. but not on Putty

Earsistemas New Member Posts: 26
edited October 11 in UP Core Plus Windows

I am trying to connect a board (UP CORE PLUS) via UART, that uses windows 10, to another microsystem board. I know that the port is working properly because I can monitorize it via windows Minicom or Device Monitoring Studio (DMS). But when I use windows PUTTY, I always get the same error:

unable to open connection to com1: error 87 the parameter is not correct

Please, any help is wellcome. Why a port is working on windows DMS and not on windows PUTTY?
Thank you


  • camillus
    camillus Administrator, Moderator, AAEON Posts: 59 admin

    Hi @Earsistemas ,

    Check that you are using the correct COM port for Putty, One way of finding out, open device manager before plugging the USB to UART cable and monitor for the new COM port. The DMS and Putty will not necessarily use the same COM port.

  • Earsistemas
    Earsistemas New Member Posts: 26

    Thanks Camillus for your quick answer. Let me explain a little more and include some screenshots: In windows 10, the UP CORE PLUS creates the UART ports perfectly, and you can see them in the device manager:

    When you test them, the USB and UART ports are working fine. I have monitorized them using DMS or Moba (minicom engine) in windows:

    But, when we try COM1 using PUTTY (windows), we always get this error:

    COM3 and all USB virtual PORTS work fine in PUTTY, but it is imposible to work with port COM1, which is the UART port we need.
    The reason why we need to see information via COM1 in PUTTY windows is that we need to see the port COM1 in the Python program we use in our system. We have been told that if PUTTY windows does not see the UART port, Python (pyserial) neither. This is why we need to test COM1 via windows PUTTY.
    Our system works perfectly in Ubuntu 20.04: all ports work fine including COM1 using Cutecom.

    Thanks for your kind help.

  • Earsistemas
    Earsistemas New Member Posts: 26