NI-DAQ Function Reference Chapter 6
PC-OPDIO-16 User Manual 6-2 © National Instruments Corporation

Primary Types

Table 6-2 shows the primary type names and their ranges.

Table 6-2. Primary Type Names

Type Description Range Type
Name C BASIC Pascal
I16 16-bit signed
integer -32,768 to 32,767 short Integer (for example:
deviceNum%)Integer
U16 16-bit unsigned
integer 0 to 65,535 unsigned
short Not supported by
BASIC. For functions
that require unsigned
integers, use the signed
integer type instead.
See the I16 description.
Word
I32 32-bit signed
integer -2,147,483,648 to
2,147,483,647 long Long integer (for
example: count&)Longint
U32 32-bit unsigned
integer 0 to 4,294,967,295 unsigned
long Not supported by
BASIC. For functions
that require unsigned
long integers, use the
signed long integer type
instead. See the I32
description.
Not supported
by Pascal. For
functions that
require
unsigned long
integers, use
the signed long
integer type
instead. See
the I32
description.
F32 32-bit single-
precision
floating point
-3.402823 x 1038 to
3.402823 x 1038 float Single-precision floating
point (for example:
num!)
Single
F64 64-bit double-
precision
floating point
-1.797683134862315 x
10308 to
1.797683134862315 x
10308
double Double-precision
floating point (for
example: voltage#)
Double
Programming Language Considerations

Apart from the data type differences, there are a few language-dependent considerations you

need to be aware of when you use the NI-DAQ API. Please read the following sections that

apply to your programming language.

Note: Be sure to include the NI-DAQ function prototypes by including the appropriate

NI-DAQ header file in your source code.