Hardware-Timed Single Point Pulse Measurement; Pulse Versus Semi-Period Measurements - National Instruments DAQ X Series User Manual

Figure 7-10 shows an example of a sample clocked buffered pulse
measurement.
Counter
S1
Armed
Gate
Source
Sample
Clock
Buffer
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Hardware-Timed Single Point Pulse Measurement

A hardware-timed single point (HWTSP) pulse measurement has the same
behavior as a sample clocked buffered pulse measurement.
Note If a pulse does not occur between sample clocks, an overrun error will occur.
Note (NI USB-634x/635x/636x Devices)
hardware-timed single point (HWTSP) operations.
For information about connecting counter signals, refer to the
Counter/Timer Pinouts

Pulse versus Semi-Period Measurements

In hardware, pulse measurement and semi-period are the same
measurement. Both measure the high and low times of a pulse. The
functional difference between the two measurements is how the data is
returned. In a semi-period measurement, each high or low time is
considered one point of data and returned in units of seconds or ticks. In a
pulse measurement, each pair of high and low times is considered one point
of data and returned as a paired sample in units of frequency and duty cycle,
high and low time or high and low ticks. When reading data, 10 points in a
semi-period measurement will get an array of five high times and five low
times. When you read 10 points in a pulse measurement, you get an array
of 10 pairs of high and low times.
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H L
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Figure 7-10. Sample Clocked Buffered Pulse Measurement
X Series USB devices do not support
section.
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Chapter 7 Counters
S2
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X Series User Manual