Communication: WinCC V6.0 to SoftPLC on same machine

Hi,

Weam trying to connect tags from a SoftPLC (WinLC RTX) to a WinCC V6.0 Interface on the same machine (Local).
The Current setup:

Station Configuration:
Index 2 : Win LC RTX
Index 125 : Station Manager (Its communication is set to PC-Local)

Wehave add a new connection (Soft PLC) to the S7 Protocol Suites
In the properties tab, we insert the value 125 and 0 respectively and the checkbox for automaic is checked.
Then weadded a tag (Input Bit).
We have inserted an I/O input and connect it to the tag.
After Activating the Interface, the I/O input is dimmed.

By checking the Communication Diagnostic, The connection that was created is disconnected.
The Log file has the following entry: Unable to connect Error Code 0x FFDF 4116.

The intarface is working fine with internal tags.

What could be the source of the problem?.
I have followed the instructions in the Getting Started Manual for WinCC V6.0
Any other leads?.

Thanks
Amir