Re: Win32:SerialPort not reading all characters

It is interesting to note that the missing characters have values of 1 and 0. In particular the run of four missing 0 (null) characters somewhat argues against the problem being buffer overrun or framing related and suggests some sort of software filtering issue.

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Comment on Re: Win32:SerialPort not reading all characters

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Re^2: Win32:SerialPort not reading all characters by sxmwb (Pilgrim) on Mar 31, 2008 at 14:53 UTC
Grandfather, I think you are right there seems to be some kind of filtering or processing that does not pass through certain types of bytes. I have included the following two settings in my code to show errors. `$port-> error_msg(1); # prints hardware messages like "Framin +g Error" $port-> user_msg(1); # prints function messages like "Waiting + for` [download] I was able to generate buffer overflows in a test I ran to prove the overflows and framing errors would be caught, but that does not account for the missing characters in my code. Since running the code does not generate buffer overflow errors at this time. Buffer overflows would account for missing characters at the end of the stream. The file from the scanner is 67452 bytes and the program here downloads 62451 bytes. I was running a port monitor and watch the 01, 00, 02 and 03 come from the scanner on the download but they did not seem to get passed through Win32::SerialPort as characters. The program I am mimicing does include all those characters in the output file. Thanks Mike	[reply] [d/l]

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Re^2: Win32:SerialPort not reading all characters
by sxmwb (Pilgrim) on Mar 31, 2008 at 14:53 UTC

$port-> error_msg(1);          # prints hardware messages like "Framin
+g Error"
$port-> user_msg(1);          # prints function messages like "Waiting
+ for
[download]

The file from the scanner is 67452 bytes and the program here downloads 62451 bytes. I was running a port monitor and watch the 01, 00, 02 and 03 come from the scanner on the download but they did not seem to get passed through Win32::SerialPort as characters. The program I am mimicing does include all those characters in the output file.

Thanks Mike

[reply]
[d/l]