Golf 4 Diagnostic Adapter: Which Version?

Hey fellow mechanics,
Which of the three versions of the diagnostic adapter would you recommend for a Volkswagen Golf 4? The simplest version, the extended version from Ulf, or the one with the MAX232 chip from Maik? Which one works best and most reliably in the G4?
Unfortunately, I don't have time for my own experiments.

Thank you and best regards.

Eike.

Hi Eike,
'On my Golf 3 TDI, manufactured in 1994, even the cheapest adapter (connected to a standard PC) worked, although I only had problems because my laptop didn't recognize the adapter (due to issues with the interface levels). That's why I also have a version using the MAX232 chip to avoid this problem.'

Regards,
Maik.

From the perspective of an electrical engineer, version 2 is preferable (due to its use of readily available components and better pulse shaping). The circuit involves potential isolation with adjustable pulse amplitudes. There's not much that can go wrong here. Unfortunately, another test is pending because the OBD II connector is missing.