National Instruments NI USB-6009 - Manual (Page 16)

NI USB-6008/6009 User Guide and Specifications 16 ni.com
Signal Descriptions
Table 6 describes the signals available on the I/O connectors.
Table 6. Signal Descriptions
Signal Name Reference Direction Description
GND — — Ground—The reference point for the
single-ended AI measurements, bias
current return point for differential mode
measurements, AO voltages, digital
signals at the I/O connector, +5 VDC
supply, and the +2.5 VDC reference.
AI <0..7> Varies Input Analog Input Channels 0 to 7—For
single-ended measurements, each signal is
an analog input voltage channel. For
differential measurements, AI 0 and AI 4
are the positive and negative inputs of
differential analog input channel 0.
The following signal pairs also form
differential input channels:
<AI 1, AI 5>, <AI 2, AI 6>, and
<AI 3, AI 7>.
AO 0 GND Output Analog Channel 0 Output—Supplies the
voltage output of AO channel 0.
AO 1 GND Output Analog Channel 1 Output—Supplies the
voltage output of AO channel 1.
P1.<0..3>
P0.<0..7> GND Input or
Output Digital I/O Signals—You can
individually configure each signal as an
input or output.
+2.5 V GND Output +2.5 V External Reference—Provides a
reference for wrap-back testing.
+5 V GND Output +5 V Power Source—Provides +5 V
power up to 200 mA.
PFI 0 GND Input PFI 0—This pin is configurable as either a
digital trigger or an event counter input.