Hello Sonet -
When you say the 'return type is string' are you creating a dll function who's return value is a string? TestStand's CVI adapter step types only support functions that return VOID or some sort of numeric value(int, double, float, short, long, etc...). Our DLL flexible adapter step types are similar. Your best bet is to pass your string/char buffer as a parameter to your function and make use of the ability to share data 'by reference' with your code.
If this isn't an answer to your question, please provide a function prototype and description of how you are calling it from TestStand and I will try again.
Regards,
Elaine R.
National Instruments
http://www.ni.com/support
