Semi-Period Measurement; Single Semi-Period Measurement - National Instruments NI cDAQ-9181 User Manual

Figure 5-10 shows an example of a sample clocked buffered pulse measurement.
Figure 5-10. Sample Clocked Buffered Pulse Measurement
Counter
Armed
Gate
Source
Sample
Clock
Buffer
If a pulse does not occur between sample clocks, an overrun error occurs.
Note
For information about connecting counter signals, refer to the
section.

Semi-Period Measurement

In semi-period measurements, the counter measures a semi-period on its Gate input signal after
the counter is armed. A semi-period is the time between any two consecutive edges on the Gate
input.
You can route an internal or external periodic clock signal (with a known period) to the Source
input of the counter. The counter counts the number of rising (or falling) edges occurring on the
Source input between two edges of the Gate signal.
You can calculate the semi-period of the Gate input by multiplying the period of the Source
signal by the number of edges returned by the counter.
Refer to the following sections for more information about semi-period measurement options:

Single Semi-Period Measurement

•
Implicit Buffered Semi-Period Measurement
•
Pulse versus Semi-Period Measurements
Refer to the
differences between semi-period measurement and pulse measurement.
Single Semi-Period Measurement
Single semi-period measurement is equivalent to single pulse-width measurement.
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NI cDAQ-9181/9184/9188/9191 User Manual
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Default Counter/Timer Routing
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