Contents

Pulse-Width Measurement ..............................................................................

9-5

Single Pulse-Width Measurement.....................................................

9-5

Buffered Pulse-Width Measurement.................................................

9-5

Period Measurement........................................................................................

9-6

Single Period Measurement ..............................................................

9-7

Buffered Period Measurement ..........................................................

9-7

Semi-Period Measurement ..............................................................................

9-9

Single Semi-Period Measurement.....................................................

9-9

Buffered Semi-Period Measurement.................................................

9-9

Frequency Measurement .................................................................................

9-10

Method 1—Measure Low Frequency with One Counter..................

9-10

Method 1b—Measure Low Frequency with One Counter

 

(Averaged)......................................................................................

9-11

Method 2—Measure High Frequency with Two Counters...............

9-11

Method 3—Measure Large Range of Frequencies Using

 

Two Counters .................................................................................

9-12

Choosing a Method for Measuring Frequency .................................

9-13

Position Measurement .....................................................................................

9-15

Measurements Using Quadrature Encoders......................................

9-15

Measurements Using Two Pulse Encoders.......................................

9-17

Two-SignalEdge-Separation Measurement....................................................

9-18

Single Two-SignalEdge-Separation Measurement ..........................

9-18

Buffered Two-SignalEdge-Separation Measurement ......................

9-19

Counter Output Applications .........................................................................................

9-20

Simple Pulse Generation .................................................................................

9-20

Single Pulse Generation ....................................................................

9-20

Single Pulse Generation with Start Trigger ......................................

9-20

Retriggerable Single Pulse Generation .............................................

9-21

Pulse Train Generation ....................................................................................

9-22

Continuous Pulse Train Generation ..................................................

9-22

Frequency Generation .....................................................................................

9-23

Using the Frequency Generator ........................................................

9-23

Frequency Division .........................................................................................

9-24

Pulse Generation for ETS................................................................................

9-24

Counter Timing Signals .................................................................................................

9-25

Counter n Source Signal..................................................................................

9-26

Routing a Signal to Counter n Source...............................................

9-26

Routing Counter n Source to an Output Terminal ............................

9-26

Counter n Gate Signal .....................................................................................

9-27

Routing a Signal to Counter n Gate ..................................................

9-27

Routing Counter n Gate to an Output Terminal................................

9-27

Counter n Aux Signal ......................................................................................

9-27

Routing a Signal to Counter n Aux...................................................

9-27

© National Instruments Corporation

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NI USB-621x User Manual