National Instruments PXI-6031E, Руководство пользователя

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Chapter 2 Analog Input
© National Instruments Corporation 2-3 E Series User Manual
across the input range. So, for an input range of 0 to 10 V, the voltage of
each code of a 16-bit ADC is
Some E Series devices support both unipolar and bipolar input ranges. A
unipolar input range means that the input voltage range is between 0 and
V
ref
, where V
ref
is a positive reference voltage. A bipolar input range means
that the input voltage range is between –V
ref
and V
ref
.
The NI-PGIA applies a different gain setting to the AI signal depending on
the input range. Gain refers to the factor by which the NI-PGIA multiplies
(amplifies) the input signal before sending it to the ADC. For example, for
the input range 0 to 100 mV, the NI-PGIA applies a gain of 100 to the
signal; for an input range of 0 to 5 V, the NI-PGIA applies a gain of 2.
Choose an input range that matches the expected input range of your signal.
A large input range can accommodate a large signal variation, but reduces
the voltage resolution. Choosing a smaller input range improves the voltage
resolution, but may result in the input signal going out of range.
For more information about programming these settings, refer to the
NI-DAQmx Help or the LabVIEW 8.x Help .
Tables 2-1, 2-2, and 2-3 show the input ranges and resolutions supported
by each E Series device.
Table 2-1.
Input Ranges for NI 6020E, NI 6040E, NI 6052E, NI 6062E, and NI 6070E/6071E
Input Range Gain Polarity
Precision
NI 6020E NI 6040E NI 6052E NI 6062E
NI 6070E/
6071E
0 to +10 V
0 to +5 V
0 to +2V
0 to +1 V
0 to +500 mV
0 to +200 mV
0 to +100 mV
1
2
5
10
20
50
100
Unipolar 2.44 mV
1.22 mV
488 µ V
244 µ V
122 µ V
48.8 µ V
24.4 µ V
2.44 mV
1.22 mV
488 µ V
244 µ V
122 µ V
48.8 µ V
24.4 µ V
153 µ V
76.3 µ V
30.5 µ V
15.3 µ V
7.63 µ V
3.05 µ V
1.53 µ V
2.44 mV
1.22 mV
488 µ V
244 µ V
122 µ V
48.8 µ V
24.4 µ V
2.44 mV
1.22 mV
488 µ V
244 µ V
122 µ V
48.8 µ V
24.4 µ V
10 V 0 V
–
2
16
--------------------------- 153 µ V =