With v1.4.0 they went with proprietary USB VID/PIDs, but it's still an FTDI RS-232 chip underneath. However, the PA Soft / BMW Scanner cable uses a bog standard FTDI RS-232 chip. With an E90 you get to do the D-CAN to RS-232 step (07+). The BMW-specifc protocol that you'd find on an E39 (DS2) doesn't rely on any esoteric functions. If you're talking about ISO 9141-2 / KWP2000 style OBD2 init, that requires 5 baud handshake and that's why you use an OBD2 dongle (often ELM327 based). Unfortunately the functions the bulk of them do not emulate are required for diagnostic work.You're going to have to be a lot more specific than that. These often result in limited or no communication with some modules whilst performing perfectly with others - the reason is that they emulate most serial port functions (i.e. Read on - the vast majority of USB to RS232 adapters are not fine for diagnostic work.
