National Instruments NI USB-6009 - Manual (Page 21)

© National Instruments Corporation 21 NI USB-6008/6009 User Guide and Specifications
DACs
Digital-to-analog converts (DACs) convert digital codes to analog
voltages.
Connecting Analog Output Loads
To connect loads to the NI USB-6008/6009, connect the positive lead of the
load to the AO terminal, and connect the ground of the load to a GND
terminal.
Figure 13. Connecting a Load
Minimizing Glitches on the Output Signal
When you use a DAC to generate a waveform, you may observe glitches in
the output signal. These glitches are normal; when a DAQ switches from
one voltage to another, it produces glitches due to released charges. The
largest glitches occur when the most significant bit of the DAC code
changes. You can build a lowpass deglitching filter to remove some of
these glitches, depending on the frequency and nature of the output signal.
Refer to
ni.com/support for more information about minimizing
glitches.
Digital I/O
The NI USB-6008/6009 has 12 digital lines, P0.<0..7> and P1.<0..3>,
which comprise the DIO port. GND is the ground-reference signal for the
DIO port. You can individually program all lines as inputs or outputs.
NI USB-6008/6009
GND
AO
Load