© National Instruments
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3-1
3
Counters
The NI 6612 has eight general-purpose 32-bit counter/timers and a frequency generator. The
general-purpose counter/timers can be used for many measurement and pulse generation
applications. Figure 3-1 shows Counter 0 and the frequency generator. All eight counters are
identical.
Figure 3-1.
Counter 0 and Frequency Generator
Counters have eight input signals, although in most applications only a few inputs are used.
Each counter has a FIFO that can be used for buffered acquisition and generation. Each counter
also contains an embedded counter (Embedded Ctr
n
) for use in what are traditionally
two-counter measurements and generations. The embedded counters cannot be programmed
independent of the main counter, and signals from the embedded counters are not routable.
Counter measurements support several options for determining when each measurement is
taken. For example, you can configure the counter to take a measurement on each edge of a
sample clock.
For measurements using a sample clock, you must configure the NI 6612 to route a signal to the
sample clock input of the counter. The NI 6612 does not have a dedicated circuit to generate a
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