Hello,
the 0xC0000005 is the "classic" Access violation. This exception happen when your software try to read or write on a not allowed memory area. In pure C this typically happen when you use a pointer that hold an incorrect value (point to a reserved memory area).
I don't know exactly how the memory is managed in an RT system, but I think that you have more control (and more chances to create a bug) than in a regular LV-under-Windows.
I can only suggest to you to start checking how data are passed between various sw module/sub-vi (data type, array size, by ref/by val ecc...).
