On Friday 18 October 2013 17:15:36 Stefano Cordibella wrote: > Thank you Frédéric for your suggestion! > I am looking into the datasheet in order to discover these values. > > BTW the QtSerialPort library doesn't report anything and from its side > everithing is working properly... > This could be a serial port library bug or a driver issue??? > > I think that there is no clear border, but the low level library > implementation (I mean the unix system call invoked from library) may be > better managed in order to check that the port is properly set to the > requested frequency...
I observed the same problem recently on a ADDI-DATA APCI-7500-3 on Windows. The pci board is a carrier board on which you plug from one to four serial interfaces. The serial interfaces have to be ordered with an oscillator capable of producing the baud rates you need. We ordered a serial interface with the wrong oscillator. The driver happily accepted the requested baud rate without any error but the scope clearly showed the board to emit a signal at another baud rate. Then I wrote a small program to scan every possible baud rate and report whether the baud rate was accepted or not. I found out that most of them were accepted and rounded up or down to the closest physically attainable baud rate. Only baud rates too far away from a valid baud rate returned an error. The accepted baud rate ranges were roughly centered on the physically valid baud rates. In my case, I used the Windows API. Therefore, I can't speak about Qt or Linux. It may not qualify as a driver issue either. It is how the driver works by design. The manufacturer might even call it a feature :-) Frederic _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
