Define variable with void data type.

[LabVIEW_Vish]

Hi,

I would like to define a variable and a structure with void data type.

How could I define it?

regards.

[SijinK]

Hi Labview_Vish,

TestStand doesn't have any void data type defined. But what exactly are you using this for?

Hope to hear back

SijinK

National Instruments

[LabVIEW_Vish]

HI SijinK,

Thanks for the reply.

I want to call some "dll" in the TestStand. In this "dll", function requires some variable of void data type as input.

e.g.  dll - Test.dll

Function  - short int Func_a (void var_a, long var_b, void *var_c, custom_struc *var_d)

I want to call this function in the TestStand. Using "C/C++ Dll" adapter module and "Action" step type, I will call this dll and its function.

For passing values to this function, I need to define some variable with respective data type.

Please let me know how could I do this.

Regards.

[SijinK]

HI labview_vish,

You would have to pass the void and the void * parameters as integers from TestStand. This has worked for me before. Please let me know how things went when you tried this.

SijinK

National Instruments

[pdobratz]

In C, the void* data type is used as a generic pointer to memory.  This is generally used for functions like malloc that have no way of knowing what the contents are of the memory you would like to use.  In order to correctly pass information to your DLL, you need to know more about the function you are calling.  This parameter could really refer to anything.  Is it supposed to be an input parameter or an output parameter or both?  Is it supposed to be a single value or an array of values?  Perhaps it's type is supposed to be specified by another parameter to the same function.  In any case you will need to edit the prototype directly in TestStand and give it the appropriate type for your application.

--Peter

[LabVIEW_Vish]

Thank you, Peter and SijinK.

Currently I can define the Void or Void* as interger and it work for me. But in future I might need to define as the specific datatype as mentioned by Peter.

[HeinzG.]

Hi,

Peter is right "In any case you will need to edit the prototype directly in TestStand and give it the appropriate type for your application". Also take a look at this KnowledgeBase. 

Kind regards

Heinz