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Chapter 3
Counter Input
For measurements using a sample clock, you must configure the NI 6614 to route a signal to the
sample clock input of the counter. The NI 6614 does not have a dedicated circuit to generate a
counter sample clock. You can route an external signal or one of many different internal signals
as the sample clock. For example, you can generate a signal using one counter and route that
signal to the sample clock of another counter. Refer to Chapter 5,
, for
more information about which signals can be used as the source.
Counter Input Applications
The following sections list the various counter input applications available:
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Edge Counting
In an Edge Counting measurement task, the counter counts the number of active edges of a
signal. Figure 3-2 shows an example of edge counting.
Figure 3-2.
Edge Counting
Channel Settings
By default, the counter:
•
starts the count at 0
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counts edges on a default PFI terminal. Refer to Chapter 5,
, for
more information.
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counts rising edges
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counts up always
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