Frequency Measurement; Low Frequency With One Counter - National Instruments DAQ X Series User Manual

Figure 7-11 shows an example of an implicit buffered semi-period
measurement.
For information about connecting counter signals, refer to the
Counter/Timer Pinouts

Frequency Measurement

You can use the counters to measure frequency in several different ways.
Refer to the following sections for information about X Series frequency
measurement options:
•
•
•
•
•

Low Frequency with One Counter

For low frequency measurements with one counter, you measure one
period of your signal using a known timebase.
You can route the signal to measure (fx) to the Gate of a counter. You can
route a known timebase (fk) to the Source of the counter. The known
timebase can be an onboard timebase, such as 100 MHz Timebase, 20 MHz
Timebase, or 100 kHz Timebase, or any other signal with a known rate.
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Counter
Starting
Armed Edge
Gate
Source
Counter Value 0
Buffer
Figure 7-11. Implicit Buffered Semi-Period Measurement
section.
Low Frequency with One Counter
High Frequency with Two Counters
Large Range of Frequencies with Two Counters
Sample Clocked Buffered Frequency Measurement
Hardware-Timed Single Point Frequency Measurement
7-13
Chapter 7
1 2 3 1 1 2 1
3 3
3
3 1
2
1 1
2
Default
X Series User Manual
Counters