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National Instruments Data Acquisition Device NI USB-621x User Manual

Page 51

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Chapter 4

Analog Input

NI USB-621x User Manual

4-18

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Figure 4-10. AI Sample Clock Too Fast For AI Convert Clock;

AI Sample Clock Pulses Are Gated Off

Figure 4-11. AI Convert Clock Too Fast For AI Sample Clock;

AI Convert Clock Pulses Are Gated Off

Figure 4-12. AI Sample Clock and AI Convert Clock Improperly Matched;

Leads To Aperiodic Sampling

AI Sample Clock

AI Convert Clock

Sample #1

Sample #2

Sample #3

Channel Measured 1

2

3

0

1 2 3

0 1

2

3

0

AI Sample Clock

AI Convert Clock

Sample #1

Sample #2

Sample #3

1 2 3

0

1 2 3

0 1

2

3

0

Channel Measured

AI Sample Clock

AI Convert Clock

Sample #1

Sample #2

Sample #3

1 2 3

0

0

Channel Measured

1 2 3

0