The LabVIEW Import Shared Library wizard converts the following shared library data types to the indicated LabVIEW data types.

  • numeric and numeric pointer
  • string and string pointer
  • void and void pointer
  • Boolean and Boolean pointer
  • cluster and cluster pointer

For return values in the shared library functions, the Input/Output type can only be Output. The Configure VIs and Controls page of the Import Shared Library wizard displays an exclamation point icon to indicate that LabVIEW cannot process the specified data type. For data types that LabVIEW does not support, create a custom control and link to it. Refer to the Example: Importing Functions from a Shared Library File topic for more details.

Numeric

C Data Type Icon I/O Type LabVIEW Control Type Pass Type LabVIEW Representation Unsigned Representation (unsigned int)
__int8

Input Numeric Value I8 U8
__int16

Input Numeric Value I16 U16
__int32

Input Numeric Value I32 U32
__int64

Input Numeric Value I64 U64
char

Input Numeric Value I8 U8
short

Input Numeric Value I16 U16
int

Input Numeric Value I32 U32
long

Input Numeric Value I32 U32
float

Input Numeric Value SGL
double

Input Numeric Value DBL

Numeric Pointer

C Type Icon I/O Type I/O Type (const int*) LabVIEW Control Type Pass Type LabVIEW Representation Unsigned Representation (unsigned int*)
__int8 *

Input/Output Input Numeric Pointer I8 U8
__int16 *

Input/Output Input Numeric Pointer I16 U16
__int32 *

Input/Output Input Numeric Pointer I32 U32
__int64 *

Input/Output Input Numeric Pointer I64 U64
short *

Input/Output Input Numeric Pointer I16 U16
int *

Input/Output Input Numeric Pointer I32 U32
long *

Input/Output Input Numeric Pointer I32 U32
float *

Input/Output Input Numeric Pointer SGL
double *

Input/Output Input Numeric Pointer DBL

String and String Pointer

C Type Icon I/O Type LabVIEW Control Type
char*

Input/Output String
Char []

Input/Output String
const char *

Input String
const char []

Input String

Void and Void Pointer

C Type Icon I/O Type LabVIEW Control Type Pass Type LabVIEW Representation
void

void means no control is needed and can appear only as the return control
void*

Input/Output Numeric Value U32
const void *

Input Numeric Value U32

Boolean and Boolean Pointer

C Type Icon I/O Type LabVIEW Control Type Pass Type
bool

Input Boolean Value
bool *

Input/Output Boolean Pointer
const bool *

Input Boolean Pointer

Cluster and Cluster Pointer

C Type Icon I/O Type LabVIEW Control Type Pass Type
struct

Input Cluster Value
Struct *

Input/Output Cluster Pointer
const struct *

Input Cluster Pointer