Vinculum and CP2102

Has anyone setup a correct communication with the Vinculum and the CP2102? :(
I wanted to setup a communication line: PC (COM1) - Vinculum/VDIP1 - CP2102 - PC (COM3)

I tried it and got some results, but they are not satisfying to me.
For exemple, I try to read the data sent from COM3 to COM1 with the "drd"-command. I have to send the drd twice to the Vinculum to get the whole data sent by the COM3.

I can fix the working mode of the CP2102 by sending "SSU $41 00 01 00 00 00 00 00" to the Vinculum and to set the baudrate of the CP2102 I have to send "SSU $41 01 80 01 00 00 00 00". But is there anywhere a list with the complete binary commands? Or a user manual which one can filter out the commands??? :confused:

I guess one has to reengineer the commands from some drivers or so. :eek: