The communication board is very small and has only a few parts, which I bought at Reichelt.  I asked a friend to help me with the smd UART and driver chip. They were so small, he needed a microscope to fix it. But all is done and the soldered PCB is built in the plastic little box.

So, after fixing the necessary cables (plus 13.8V, USB to PC), I connected the little box to the Controller PCB. Power on the communication box.

Now I should be able to see the communication PCB in the PC program, so start up the program (T1KS_V208.application), and select the correct COM-port, which is COM5 in my case. And,.....thanks to the fact I already fixed the fusebit problem (enabling the external oscillator), I got connection. Look in the picture below.