How to send a string to CVI .c and get string return through TestStand sequence?

[plit string]

Hi, I am using TestStand 3.1 and I have the StringConverter.c with CVI 8.0 with the function:

char * string_concat_2 (char* str1,char* str2)
{
 char * str_ret;
 
 str_ret = calloc(200, sizeof(char*));
 
 str_ret = strcat (str_ret, str1);
 str_ret = strcat (str_ret, str2);
 
 return str_ret;
}

I would like to use it  through Teststand, so I add a sequence using 'StringValueTest'. I Spectify Module CVI &  link to StringConverter.c and type in Function Name: char * string_concat_2 (char* str1,char* str2)

1. How I define to send the string1 ("Hello") & string2 ("World") to the Module?

2. How I define to string return ("HelloWorld" from the Module?

Thanks

[Gavin F]

Hi plit string,

You will need to have a parameter passed by reference to return the string.  To do this, use a "C String Buffer" instead of a "C String (const)" parameter type.  There is documentation on this in TestStand Help.  Here is a quote from there:

"When using string parameters, use the C String Buffer or Unicode String Buffer type if you want the function to be able to change the contents of the argument in TestStand. Use the C String or Unicode String type if the DLL function does not modify the argument. You can pass a literal string, a TestStand string property, or an expression that evaluates to a string as the value of a string parameter."

[plit string]

Sorry about my late reply, since I had holidays. I changed as you suggested and it works. However only after I did Edit Source Code in Specify Module ---> it created automatically the tscvirun_supp.c

Thanks for help