National Instruments 3.21E+04 用户手册
Chapter 3 Hardware Overview
AT-MIO/AI E Series User Manual
3-12
National Instruments Corporation
Figure 3-7. Dither
You cannot disable dither on the AT-MIO-16XE-10, AT-AI-16XE-10,
or AT-MIO-16XE-50. This is because the resolution of the ADC is so
fine that the ADC and the PGIA inherently produce almost 0.5 LSB rms
of noise. This is equivalent to having a dither circuit that is always
enabled.
or AT-MIO-16XE-50. This is because the resolution of the ADC is so
fine that the ADC and the PGIA inherently produce almost 0.5 LSB rms
of noise. This is equivalent to having a dither circuit that is always
enabled.
Multiple-Channel Scanning Considerations
All of the AT E Series boards can scan multiple channels at the same
maximum rate as their single-channel rate; however, you should pay
careful attention to the settling times for each of the boards. The
settling time for most of the AT E Series boards is independent of the
selected gain, even at the maximum sampling rate. The settling time for
the high channel count and very high-speed boards is gain dependent,
which can affect the useful sampling rate for a given gain. No extra
settling time is necessary between channels as long as the gain is
maximum rate as their single-channel rate; however, you should pay
careful attention to the settling times for each of the boards. The
settling time for most of the AT E Series boards is independent of the
selected gain, even at the maximum sampling rate. The settling time for
the high channel count and very high-speed boards is gain dependent,
which can affect the useful sampling rate for a given gain. No extra
settling time is necessary between channels as long as the gain is
100
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a. Dither disabled; no averaging
b. Dither disabled; average of 50 acquisitions
c. Dither enabled; no averaging
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500
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-2.0
0.0
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d. Dither enabled; average of 50 acquisitions
LSBs
LSBs
LSBs
LSBs
6.0
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
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500
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-6.0
6.0
100
200
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400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0