OBD2 Scanner for VW Passat 2000 PD

Hello, can anyone tell me which hardware/software combination is needed for a Passat PD with an AJM engine, manufactured in May 2000? I tried using VAG COM with the 9141 interface from ProChip, but it didn't work - that's why I'm asking.

Regardless of the car:
- A "true" serial interface is recommended; otherwise, follow Rosstech's recommendations regarding USB-to-serial adapters.
- A computer with a clean, unadulterated version of Windows, possibly including an antivirus scanner and other background programs.
- Use an interface adapter from the diagnostics website here or one offered by Ross-Tech.

Best regards, Rainer.