problems about Call Library Function Node

[plateaugao]

Dear NI Engineer,  I am writing program using LabVIEW 8.5 and i have to use Call Library Function Node to call extern program written in VC++. The source code written in VC++  is  about 3,000 lines long and can work well in VC++ envirment.  But when I call the DLL format of the souce code using Call Library Function, it didn't work properly .Sometimes the results are right, but sometimes all the outputs is zero. I am sure the procedures and parameters are set right when building DLL , and i have built some successful DLL according to them. So could you tell me if Call Library Function  code have some limitiations on the dll being called, such as dll length, etc.? what factors can cause the above problems?And in which aspects i can reedit the source code to avoid such problem? Thanks?  Best  Regards, Plateaugao  

[smercurio_fc]

The Call Library Function cannot call C++ code directly. It is designed (and limited) to C code. Thus, you must "flower" each of your functions with extern c declarations. Have you done this? Also, have you selected the proper calling convention?