For the audience's information, Google found ftp://kopfweb.de/ko/kopfweb.de/AutomotiveInterface/AID/V3.05/AID.h which lead to ftp://kopfweb.de/ko/kopfweb.de/AutomotiveInterface/Documentation/AI%20USB%20Communication.pdf.
Perhaps you aren't calling KSENT_TXInit() properly?
The documentation says that the second argument should be a pointer to a 12-bit value stored in 2 bytes, yet you are setting 4 bytes. So, perhaps you are encoding those bits incorrectly?
Searching for your error message (in German) on the internet only found one other node on this web site. But that thread contains examples of dumping lots of "what was going on" details for such a failure. Doing such for your case might provide more clues. See Strawberry Perl 64bit on Win7 crashes on DBI-function.