problem about calling a labview dll from VC 6.0

[soslotos]

I design a program in labview to generate two pulses to control the laser.
I have built a dll from the vi in labview 7.1 and called the dll from VC 6.0.
But The function I called from VC 6.0 didn't work at all.

Then I built a dll for the Generate Single Pulse(DAQ-STC).vi,and called it from the VC 6.
The calling function doesn't work,either.
But the vc could call some easy functions created by labview.


the follow is the reports in the debug window:
Loaded 'C:\WINNT\system32\ntdll.dll', no matching symbolic information found.
Loaded 'F:\soslotos\labviewcode\total\testmutidll\gs.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\version.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\KERNEL32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\lz32.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\USER32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\GDI32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\ADVAPI32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\rpcrt4.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\imm32.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\lpk.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\usp10.dll', no matching symbolic information found.
Loaded 'C:\Program Files\National Instruments\Shared\LabVIEW Run-Time\7.1\lvrt.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\winmm.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\WINSPOOL.DRV', no matching symbolic information found.
Loaded 'C:\WINNT\system32\mpr.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\COMDLG32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\SHLWAPI.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\COMCTL32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\SHELL32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\msvcrt.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\OLEAUT32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\OLE32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\wsock32.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\ws2_32.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\ws2help.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\SETUPAPI.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\USERENV.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\NETAPI32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\secur32.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\ntdsapi.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\dnsapi.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\WLDAP32.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\netrap.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\samlib.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\mmdrv.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\MSCTF.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\msimg32.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\clbcatq.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\mydocs.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\SHDOCVW.DLL', no matching symbolic information found.
Loaded 'C:\WINNT\system32\msi.dll', no matching symbolic information found.
Loaded 'C:\Program Files\National Instruments\Shared\nicont.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\msvcp60.dll', no matching symbolic information found.

[rolfk]

The information you provide does not give enough information. The debug log you show only is about all the possible DLLs Visual C is loading on behalve of your application and that they do not contain debug information which is totally normal unless you install checked build (special debug) versions of Windows.

The VI you show does not have any front panel control so it will be a void function(void) call only in Visual C. This is of course not a very good idea as you don't even get any error code, which might occur during execution of the VI in the DLL. I would at least chain the error cluster of the VIs together and return the code in the error cluster in a front panel control and then as return value of the function. That way you will see a non-0 value returned to Visual C if any error occurres and looking up the error number in the LabVIEW error handler VI will give you some more hints what might be going wrong.

Rolf Kalbermatter