Chapter 1 Introduction
© National Instruments Corporation 1-3 PC-DIO-24 User Manual
NI-DAQ Driver Software
The NI-DAQ driver software is included at no charge with all National Instruments DAQ
hardware. NI-DAQ is not packaged with SCXI or accessory products, except for the SCXI-1200.
NI-DAQ has an extensive library of functions that you can call from your application
programming environment. These functions include routines for analog input (A/D conversion),
buffered data acquisition (high-speed A/D conversion), analog output (D/A conversion),
waveform generation, digital I/O, counter/timer operations, SCXI, RTSI, self-calibration,
messaging, and acquiring data to extended memory.
NI-DAQ has both high-level DAQ I/O functions for maximum ease of use and low-level DAQ
I/O functions for maximum flexibility and performance. Examples of high-level functions are
streaming data to disk or acquiring a certain number of data points. An example of a low-level
function is writing directly to registers on the DAQ device. NI-DAQ does not sacrifice the
performance of National Instruments DAQ devices because it lets multiple devices operate at
their peak performance.
NI-DAQ also internally addresses many of the complex issues between the computer and the
DAQ hardware such as programming interrupts and DMA controllers. NI-DAQ maintains a
consistent software interface among its different versions so that you can change platforms with
minimal modifications to your code. Figure 1-1 illustrates the relationship between NI-DAQ and
LabVIEW and LabWindows/CVI.
LabWindows/CVI
(PC or Sun 
SPARCstation)
LabVIEW 
(PC, Macintosh, or 
Sun SPARCstation)
Conventional 
Programming 
Environment 
(PC, Macintosh, or 
Sun SPARCstation)
NI-DAQ
Driver Software
DAQ or
SCXI Hardware
Personal 
Computer or 
Workstation
Figure 1-1. The Relationship between the Programming Environment,
NI-DAQ, and Your Hardware