Re: Urgent, COM port problem

From: Paul G. Tobey [eMVP] (ptobey_no_spam_at_instrument_no_spam.com)
Date: 02/27/04 

Date: Fri, 27 Feb 2004 15:44:17 -0700

Check the registry on the running device. Is the COM port driver listed in
HKLM/Drivers/Active? If not, check the settings in the registry for the
driver (HKLM/Drivers/BuiltIn). If this is the case, you should probably
capture the debug output from the OS and see if anything shows up.

If the driver *is* listed, what happens when you try to send data to it?
Does the data simply not appear, but CreateFile() works? Does the
WriteFile() call return an error? If so, what error? Are you sure that you
don't have handshaking enabled and one of the handshake signals connected to
the wrong value (telling the port not to send)?

Paul T.

"CE" <hcheng@optonline.net> wrote in message
news:OyFQpzX$DHA.792@TK2MSFTNGP11.phx.gbl...
Blank
I use PB4.2 built a CE 9MB image and I wrote a com port test program, I can
send data to COM port, no problem. Then I add some components to CE image,
now CE image is about 20MB, now I found my program can't send data to COM1.
I have no idea why this happen, I searched components I added, they have
nothing to do with COM port.

Does any body know what caused this and how to fix this? Thank you very
much!

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