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Chapter 4 Analog Input
M Series User Manual 4-6 ni.com
Figure 4-2. NI-PGIA
Table 4-5 shows how signals are routed to the NI-PGIA.
Notice that some M Series devices do not support the AI <16..79> signals.
For differential measurements, AI 0 and AI 8 are the positive and negative
inputs of differential analog input channel 0. For a complete list of signal
pairs that form differential input channels, refer to the
I/O Connector Signal
Descriptions section of Chapter 3, Connector and LED Information .
Caution
The maximum input voltages rating of AI signals with respect to ground (and for
differential signals with respect to each other) are listed in the specifications document for
your device. Exceeding the maximum input voltage of AI signals distorts the measurement
results. Exceeding the maximum input voltage rating also can damage the device and the
computer. NI is
not liable for any damage resulting from such signal connections.
Table 4-5. Signals Routed to the NI-PGIA
AI Ground-Reference
Settings
Signals Routed to the Positive
Input of the NI-PGIA (V
in+
)
Signals Routed to the Negative
Input of the NI-PGIA (V
in–
)
RSE AI <0..79> AI GND
NRSE AI <0..15> AI SENSE
AI <16..79> AI SENSE 2
DIFF AI <0..7> AI <8..15>
AI <16..23> AI <24..31>
AI <32..39>, AI <48..55>,
AI <64..71>
AI <40..47>, AI <56..63>,
AI <72..79>
V
in+
V
m
= [V
in+
– V
in–
]
×
Gain
V
m V
in–
PGIA +
–
Measured
Voltage
Instrumentation
Amplifier