pyserial port connection problem

Nick Craig-Wood nick at
Fri Nov 17 17:30:04 CET 2006

Jon <jspeis at> wrote:
>  I wrote some code to read in info from a port using pyserial. the code
>  reads info sent by a box that is connected to my computer by an
>  rs232-to usb adapter. When I was writing the code and testing it on my
>  computer it worked fine.
>  I ran py2exe on the program (which uses wxpython for its gui) and sent
>  the output from the py2exe to another computer. now when I try to run
>  it on this other computer it fails to open the port. it gives the error
>  that it cannot createfile. the code I'm using to connect is the same as
>  it is when it worked on my computer.
>  I do notice that pyserial sees this port on the other computer as
>  \\\\.\\COM14 - while windows device manager displays it as COM14.

That is a bit too many backslashes... You can only directly open COM1
to COM9 under windows.  If you have >= 10 COM ports you need to use
the \\.\COM14 syntax.  It looks like your backslashes have been
doubled somewhere along the line, though this maybe be a printing

Are you passing the port name into pyserial or allowing the user to
choose it, or just getting pyserial to choose the n-th port?

Also are you running as adminstrator?  You may need admin rights to
open a serial port under windows (I'm not sure).

Nick Craig-Wood <nick at> --

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