On Thursday 05 September 2013 10:32:15 Dmitry Timoshkov wrote: > Wolfgang Walter <w...@stwm.de> wrote: > > When we send 17 bytes with 150 baud, no parity, one stop bit then > > we need to wait at least 17*10/150 seconds > 1000 ms > > Under Windows with both real COM-port and USB-serial cable this test takes > no longer than 890 ms, usually it's even shorter like 875 ms. Testbot VMs > also don't fail this test. If under Wine it takes > 1000 ms for you then > probably there is a bug somewhere.
How can that be? If you send 17 bytes which expands to 170 raw bits and you only sent 150 bits/s? Maybe you are using a virtual machine or your com port does not support 150 baud and chooses a different speed. Or you use a UART with a large buffer and which already signals TX-EMPTY even if it is still sending from an internal buffer. But one should not rely on that. I used a real com-port, by the way, and had a com-port-analyzer adapted to it. It exactly sends 150 bits per second which means 15 data-bytes per second. Regards, -- Wolfgang Walter Studentenwerk München Anstalt des öffentlichen Recht Abteilungsleiter IT Leopoldstraße 15 80802 München
