[Elecraft] K3 and USB1/serial interface

[David Woolley (E.L)]

Julian, G4ILO wrote:
> 

> I got mine to work once I started setting the serial port configuration to
> one stop bit not two. I believe the recommendation for the K2 was for two

If reducing the number of stop bits, in an application that is not 
critically dependent on high data rates, improves things, there is a 
serious design fault.

Non-mechanical asynchronous serial receivers need a little over half a 
stop bit.  Anything more than that simply gives a buffer against speed 
errors, and faster recovery from false start bits (in noisy environments).

The resson for two stop bits (which is actually only 1.5 for 5 unit 
codes) is to allow time for mechanical decoders to recover.  That's why 
they are only, conventionally, used for low speeds, where mechanical 
decoding is possible.

Some, very simple, hardware interfaces may be only single buffered, in 
which case going to two stop bits may be needed,  However, for those, 
reducing the number of stop bits is that last thing you want to do.



-- 
David Woolley
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