NI CompactDAQ cDAQ-917 Series User Manual

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Chapter 5 Counters
The counter counts the number of edges on the Source input while the Gate input remains active.
On each trailing edge of the Gate signal, the counter stores the count in the counter FIFO. The
STC3 transfers the sampled values to host memory using a high-speed data stream.
Figure 5-6 shows an example of an implicit buffered pulse-width measurement.
Figure 5-6. Implicit Buffered Pulse-Width Measurement
Sample Clocked Buffered Pulse-Width Measurement
A sample clocked buffered pulse-width measurement is similar to single pulse-width
measurement, but buffered pulse-width measurement takes measurements over multiple pulses
correlated to a sample clock.
The counter counts the number of edges on the Source input while the Gate input remains active.
On each sample clock edge, the counter stores the count in the FIFO of the last pulse width to
complete. The STC3 transfers the sampled values to host memory using a high-speed data
stream.
Figure 5-7 shows an example of a sample clocked buffered pulse-width measurement.
Figure 5-7. Sample Clocked Buffered Pulse-Width Measurement
Note If a pulse does not occur between sample clocks, an overrun error occurs.
For information about connecting counter signals, refer to the Default Counter/Timer Routing
section.
SOURCE
GATE
Counter Value
Buffer
10 3
3
2
212
3
3
2
Pulse
Source
Sample Clock
2 342
4
3
2 2
4
Buffer

NI CompactDAQ cDAQ-917 Series Specifications

General

Brand	NI
Model	CompactDAQ cDAQ-917 Series
Category	Chassis
Language	English