How can I pass a Variant to a C++ DLL from TestStand?

[NateHarold]

I have a VARIANT that is being returned to TestStand via COM. The variant contains a structure of integers and strings. The integers are not uniformly sized... some are 8,16, and 32 bit. Rather than try to find a way to decode this information in TestStand, I would like to pass it to a C++ DLL to do the decoding and return the information in a readily usable format. I also have need to take the aforementioned data types, send them to a DLL for conversion into a VARIANT, and then pass this variant to a COM object. Can someone please explain a way that I can use TestStand as a pass-through for VARIANTs between a COM object and a C++ DLL?

[TerryS]

Hi,

To pass a VARIANT to a C++ DLL in TestStand, you will need to create a custom data type.  From the sequence, change the View ring to Sequence File Types.  Right-click to insert a new Customer Data Type and select Container.  Now you can right-click to insert a field, which you can specify what data type it is.  Insert as many fields as needed.  After you have entered those in, right-click on the Custom Data Type name and select Properties.  Go to the C Struct Passing tab and click the "Allow Objects of this Type to be Passed as Structs".  Change packing to correlate with the C++ compiler you are using and also configure the properties for each field.

Once you have done this, you will be able to pass that VARIANT as a struct to a C++ DLL.