Chapter 3 Hardware Overview
©
National Instruments Corporation 3-5 PCI-6110E/6111E User Manual

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.

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.

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 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
LSBs
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
LSBs
6.0
100 200 300 4000 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