National Instruments pci-6110e-6111e 用户手册
Chapter 3
Hardware Overview
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National Instruments Corporation
3-5
You cannot disable dither on the 611X E board. This is because the
ADC resolution is so fine that the ADC and the PGIA inherently
produce almost 0.5 LSBrms of noise. This is equivalent to having a
dither circuit that is always enabled.
ADC resolution is so fine that the ADC and the PGIA inherently
produce almost 0.5 LSBrms of noise. This is equivalent to having a
dither circuit that is always enabled.
Figure 3-3. Effects of Dither on Signal Acquisition
Analog Output
The 611X E board supplies two channels of analog output voltage at the
I/O connector. The range is fixed at bipolar ±10 V.
I/O connector. The range is fixed at bipolar ±10 V.
a. Dither disabled; no averaging
b. Dither disabled; average of 50 acquisitions
c. Dither enabled; no averaging
d. Dither enabled; average of 50 acquisitions
LSBs
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
LSBs
6.0
100
200
300
400
0
500
-4.0
-2.0
0.0
2.0
4.0
-6.0
LSBs
6.0
PCI_E.book Page 5 Thursday, June 25, 1998 12:55 PM