I now have my K3 working with keying without any additional boxes like
netkeyer, winkeyer or similar.
Solution is fairly simple;
1. Install cwdaemon. Standard install uses parallell port for keying so
to use eg a serial port you have to modify cwdaemon config file (resided
in /etc/default). Had to set ttyS0 instead of parport0. cwdaemon seems
to start on boot with the standard debian install. So to get cwdaemon to
use serial port you need to restart; sudo service cwdaemon restart
2. Rig is controlled over same serial port. This seems to work fine as
the rig communication only uses txd and rxd lines. But there is a catch.
My standard install of hamlib triggered both dtr and rts lines and keyed
the rig unless rigctld command was changed. To avoid this you need to
ask hamlib to clear both the dtr and the rts lines. This can be done by
giving rigctld the following options in addition; -C rts_state=OFF -C
dtr_state=OFF.
3. On the K3 you need to enter the config menu and set the PTT-KEY entry
to OFF-dtr. It seems the cwdaemon keying goes over the dtr line. If you
want cwdaemon to control the ptt line, you would probably set this to
rts-dtr. Not necessary with a K3 as it provides full break-in.
The above works both with tlf and with cqrlog which is used for my main
logging. And this solution fully accepts all speed change commands and
tx stops from keyboard as it does not utilize the K3 internal keyer.
So by this I have no need for tlf (or cqrlog) to use keying via hamlib
as long as I use my K3.
But my KX3 does not allow for keying via the dtr line so the solution
will not work unless the dtr signal is routed via a transistor to the
KX3 key input. A solution which can be used for most rigs I assume.
So all in all, I do not have to prepare a nanokeyer/winkeyer or similar
extra box.
Thanks for responses which triggered me into finding a practical solution.
PS: Have not tried this on a usb-serial converter, my serial port is a
"real" serial port based on an UART 16550. But I note some usb-serial
devices has brought out the dtr line, and I would assume that this can
be made to work also on these.
73 de Olaf - LA3RK