NI C Series Getting Started

the number of ticks of the 100 MHz counter timebase. The following figure shows an
example of pulse width measurement.
Figure 17. Pulse Width Measurement
0 1 2
Counter Armed
Counter Read
Signal to Measure
Counter Timebase
Counter Value
Current Measurement
Read Value
2
2
Sample
Channel Settings
You can configure the following counter properties:
■
Input terminal of the signal-to-measure.
■
The active edge, rising or falling, the NI-9361 begins the measurement. To
measure a high pulse, set the active edge to rising. To measure a low pulse, set
the active edge to falling.
■
Maximum measurable period—You can set the maximum measurable
period of the signal. If the input signal period is slower than this value, the
counter returns a measurement value of zero. Use this property to get
updated measurement data when the signal slows down or is stopped instead
of previous measurements. To disable this feature, set the maximum
measurable period to zero. When this feature is disabled, the counter keeps
measuring until a valid measurement is detected, the counter overflows, or
the user stops the counter.
Trigger Settings
Counter Arm—You can control when the counter starts the pulse width
measurement through the counter arm control. Aer the counter is armed, it waits
for the active edge on the signal-to-measure, and then it begins measuring the pulse
width. The measurement data is only ready and valid once the counter has finished
measuring the first pulse width. The counter returns a value of zero prior to the first
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NI-9361 Getting Started

NI C Series Specifications

General

Brand	NI
Model	C Series
Category	Control Unit
Language	English