I don't see any issues with your XML file. In the ISCAN software, I see that you've correctly selected a binary format for the auxiliary outputs.
It sounds like MWServer is freezing, not crashing. Is that correct? If so, then I suspect it's blocked trying to read from the serial port, which suggests that ISCAN isn't sending data.
Have you tried using the alternate start/stop codes mentioned in the docs? As I recall, the only ISCAN manual I could find listed those values (132 and 136) as the correct ones. However, the one and only ISCAN device I've tested on expected 128 and 129, which is why those are the defaults.
Thanks for asking. For now we decided to proceed by connecting the iscan pc with the minimac using an ni card. Since this is not the most elegant solution we eventually will try to get the connection going via serial to usb. At the moment the most likely reason for the failure was that we did not use a null modem cable for the connection.
I'll keep you posted.