For Experts: Why does LabView cause System reboot while accessing hardware with driver?

Question

Hello NI Developers!
I use LabView 7.1 under Windows XP
I have a programm console application which accesses through Jungo Windriver PCI-E board.
This program works fine - and performs DMA data transfer between PC and Board's memory.
In order to implement this console application work together with LabView I did following:
1) Added this function inside the source:
 _declspec(dllexport) void LVMainFunction(uInt32 *IntValue);
_declspec(dllexport) void LVMainFunction(uInt32 *IntValue)
    AllocConsole();                   //Open new console window
    SetConsoleTitle(L"Debug Window"); //Set a title for console window
    freopen("CONOUT$","a+",stdout); //redirec standard output stream to current window so
                                    // so we are able to see "printf" outputs
   freopen("CONIN$","a+",stdin);    //redirec standard input stream to current window so
                                    // so we are able pass inputs from keyboard
   main();                          //Call applications main function which does all the work
2) Compiled this new source as DLL library
3) Call  LVMainFunction(...) function from LabView using Call Library Node
In the result: Executing VI - opens new console window, shows debug outputs and receives keyboard inputs.
It works fine till the last function, which perform DMA data transfer - and reboots PC.
1) Why does this happen?
2) I understand that opening console from Call Library Node, attaches together this console window and running VI. So If I close one of them - both windows closes.
     So does LabView have somekind of restrictions of accessing Hardware's functions? 
I can read Board's resource information and view size of memory on board, interrupt functions and other information about device, but when I try to reach
DMA my system reboots. And I understand that this should be some kind of LabView problem, cause I tried different implementations, even without use of
console window - and the result is the same.
3) Should I split the program in to two separate processes and perform data exchange using Sockets or Pipes techology?
Thank you in advance!
ACiDUser
Message Edited by ACiDuser on 11-13-2008 09:37 AM

Answer 1

Hello!
At LAST!!!
I solved this problem!
From the beginning I was following National Instruments manual on how to build DLL with external IDE:
  http://zone.ni.com/reference/en-XX/help/371361A-01​/lvhowto/building_library_project/
Set the Struct member alignment control to 1 Byte.
Now this option caused my PC to reboot!
So could someone explain  why this happened? and If it is a bad tip, so it's better to remove from manual. Then other people will not have such problems as I did
- wasting 2 monthes of time determining the problem. 
I changed it to  Set the Struct member alignment control to DEFAULT.
and now everything works fine.
Regards
Message Edited by ACiDuser on 11-13-2008 11:14 AM