Contents
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National Instruments Corporation
ix
I/O Protection.................................................................................................................6-7
Programmable Power-Up States ....................................................................................6-7
DI Change Detection .....................................................................................................6-8
Connecting Digital I/O Signals......................................................................................6-9
Getting Started with DIO Applications in Software ......................................................6-10
Single Point (On-Demand) Edge Counting ......................................7-2
Buffered (Sample Clock) Edge Counting .........................................7-3
Controlling the Direction of Counting ..............................................7-4
Single Pulse-Width Measurement.....................................................7-4
Buffered Pulse-Width Measurement.................................................7-5
Single Period Measurement ..............................................................7-6
Buffered Period Measurement ..........................................................7-7
Method 1—Measure Low Frequency with One Counter..................7-9
Method 1b—Measure Low Frequency with One Counter
(Averaged)......................................................................................7-10
Method 2—Measure High Frequency with Two Counters...............7-11
Method 3—Measure Large Range of Frequencies
Using Two Counters ......................................................................7-12
Choosing a Method for Measuring Frequency .................................7-13
Measurements Using Quadrature Encoders ......................................7-14
Measurements Using Two Pulse Encoders .......................................7-17
Two-Signal Edge-Separation Measurement....................................................7-17
Single Pulse Generation ....................................................................7-19
Single Pulse Generation with Start Trigger ......................................7-20
Retriggerable Single Pulse Generation .............................................7-21