Hi Pierre,
Here how I do it for Thetis:
First install
https://sourceforge.net/projects/com0com/ which will
give you virtual COM ports for the CAT commands.
If you now look at Device Manager in Windows, you will see com0com
serial ports COM4 to COM7. We will be using COM4 and COM5 which are
effectively each end of a virtual cable.
In Thetis Setup|CAT Control|CAT|CAT Control select Port COM4 from
the drop box, Baud 38400, Parity none, Data 8 & Stop 1
Now tick Setup|CAT Control|CAT|CAT Control|Enable CAT
On the right hand side select ID as TS-2000
That is the Thetis end of the CAT control set-up, now the for the
wsjt-x.
File|Settings|Radio|Rig - set to Kenwood TS-2000
File|Settings|Radio|Cat Control|Serial Port - COM5
File|Settings|Radio|Cat Control|Baud Rate - 38400
Leave all the reset of CAT control as is.
File|Settings|Radio|PTT Method - select CAT
Now pressing 'Test CAT' should make the button go green and Test PTT
should key the radio, so make sure you have the radio connect to
proper aerial or dummy load.
Cheers
Reid
Gi8TME/Mi0BOT