[Dx4win] dx4win and pk900 help

[Kostas sv1dpi]

Hi
Happy new year

I am trying to connect a pk900 with dx4win
I want com1 where is the pk-900 to be ready for packet and rtty
i have radio 2 for clusters and radio 1 for rtty
But then dx4win can not open rtty window.
If i make off the clusters and rtty on then the rtty window is open but an
error in dx4win.exe is on.
I think that i am doing something wrong.
Anyone to help me to set the pk-900 with dx4win?
Tks and 73
Kostas SV1DPI