Semi-Period Measurement; Sample Clocked Buffered Pulse Measurement - National Instruments NI cRIO-905x Series User Manual

Counter Armed
Gate
Source
Buffer

Sample Clocked Buffered Pulse Measurement

A sample clocked buffered pulse measurement is similar to single pulse measurement, but a
buffered pulse measurement takes measurements over multiple pulses correlated to a sample
clock.
The counter performs a pulse measurement on the Gate. On each sample clock edge, the
counter stores the high and low ticks in the FIFO of the last pulse to complete. The sampled
values will be transferred to host memory using a high-speed data stream.
The figure below shows an example of a sample clocked buffered pulse measurement.
Figure 59. Sample Clocked Buffered Pulse Measurement
Counter
Armed
Gate
Source
Sample
Clock
Buffer
Note
If a pulse does not occur between sample clocks, an overrun error occurs.
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.
Figure 58. Implicit Buffered Pulse Measurement
H L
4 2
S1
H L
2 2
2 2
H L
4 2
4 4
Default Counter/Timer Routing
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H L H L
4 2 4 2
4 4 4 4
6 2
6 2
2 2
S2
H L
2 2
3
3
3 3