National Instruments NI-VXI - Manual (Page 23)

Chapter 2 Introduction to the NI-VXI Functions
NI-VXI User Manual 2-4 © National Instruments Corporation
LabWindows/CVI
You can use the functions described in this manual with
LabWindows/CVI. LabWindows/CVI is an integrated development
environment for building instrumentation applications using the
ANSI C programming language. You can use LabWindows/CVI with
Microsoft Windows on PC-compatible computers or with Solaris on
Sun SPARCstations. The source code you develop is portable across
either platform.
National Instruments offers VXI/VME development systems for these
two platforms that link the NI-VXI driver software into
LabWindows/CVI to control VXI instruments from either embedded
VXI/VME controllers or external computers equipped with a MXI
interface. All of the NI-VXI functions described in this manual are
completely compatible with LabWindows/CVI.
Type Definitions
The following data types are used for all parameters in the NI-VXI
functions and in the actual NI-VXI library function definitions. NI-VXI
uses this list of parameter types as an independent method for
specifying data type sizes among the various operating systems and
target CPUs of the NI-VXI software interface.
C/C++ Example:
typedef char INT8; /* 8-bit signed integer */
typedef unsigned char UINT8; /* 8-bit unsigned integer */
typedef short INT16; /* 16-bit signed integer */
typedef unsigned short UINT16; /* 16-bit unsigned integer */
typedef long INT32; /* 32-bit signed integer */
typedef unsigned long UINT32; /* 32-bit unsigned integer */
Input Versus Output Parameters
Because all C/C++ function calls pass function parameters by value
(not by reference), you must specify the address of the parameter when
the parameter is an output parameter. The C/C++ “
& ” operator
accomplishes this task.
For example:
ret = VXIinReg (la, reg, &value);