National Instruments 3.21E+04 用户手册

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Chapter 3     Hardware Overview
AT-MIO/AI E Series User Manual
3-10
 National Instruments Corporation
Considerations for Selecting Input Ranges
Which input polarity and range you select depends on the expected 
range of the incoming 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 best results, you should match 
the input range as closely as possible to the expected range of the input 
signal.  For example, if you are certain the input signal will not be 
negative (below 0 V), unipolar input polarity is best.  However, if the 
signal is negative or equal to zero, inaccurate readings will occur if you 
use unipolar input polarity.  
Table 3-3.     Actual Range and Measurement Precision, AT-MIO-16XE-10, 
AT-AI-16XE-10, and AT-MIO-16XE-50  
Range 
Configuration
Gain
Actual Input Range
Precision
1
0 to +10 V
1.0
2.0
5.0
2
10.0
20.0
2
50.0
2
100.0
0 to +10 V
0 to +5 V
0 to +2 V
0 to +1 V
0 to +500 mV
0 to +200 mV
0 to 100 mV
152.59 
µ
V
76.29 
µ
V
30.52  
µ
V
15.26 
µ
V
7.63
µ
V
3.05 
µ
V
1.53 
µ
V
-10 to +10 V
1.0
2.0
5.0
2
10.0
20.0
2
50.0
2
100.0
-10 to +10 V
-5 to +5 V
-2 to +2 V
-1 to +1 V
-500 to +500 mV
-200 to +200 mV
-100 to +100 mV
305.18 
µ
V
152.59 
µ
V
61.04 
µ
V
30.52 
µ
V
15.26 
µ
V
6.10 
µ
V
3.05 
µ
V
1
The value of 1 LSB of the 16-bit ADC; that is, the voltage 
increment corresponding to a change of one count in the ADC 
16-bit count.
2
AT-MIO-16XE-10 and AT-AI-16XE-10 only
Note:
See Appendix A, Specifications, for absolute maximum 
ratings.