I have a couple of USB devices which are based upon FTDI chips. I am using the FTDI virtual serial port drivers. The devices appear to work properly except when attempting to communicate with them via cygwin python. Scripts which work o.k. with Windows python will not work properly with cygwin python. The point of failure depends upon the Windows version. Under Windows 98, the scripts fail to complete the opening of the virtual serial port,. The failure occurs in tcgetattr and an error '22, Invalid argument' is returned. I haven't followed this further into the bowels of python to work out what this means but tcgetattr() in cygwin 'C' does not fail. Under Windows 2000, the same python scripts go further but fail further down the track, early during the attempted transfer of data. The same python scripts have worked well in the past under cygwin when I use a real serial port. Are there known problems with cygwin python and USB virtual serial ports? If so, are there any solutions or work-arounds? I have tried updating (which didn't work well) and then deleting and re-installing cygwin (with the latest version as of a couple of days ago) on the Windows 98 machine. I also updated to the 2.1 version of the python serial module. The scan.py example which comes with the serial module works o.k. on Windows 2000 but not on Windows 98 (because of the way in which cygwin python fails in tcgetattr). (See attached file: cygcheck-win2000.out)(See attached file: cygcheck-win98.out) Bill Metzenthen Cochlear Limited Level 1, 174 Victoria Parade East Melbourne Vic 3002 Australia PH: +61 3 9662 1202 FAX: +61 3 9663 8652 Web: http://www.cochlear.com ============================================== "The information contained in this e-mail message may be confidential information, and may also be privileged. If you are not the intended recipient, any use, interference with, disclosure or copying of this material is unauthorised and prohibited. If you have received this message in error, please notify us by return email and delete the original message."
cygcheck-win2000.out
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cygcheck-win98.out
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