National Instruments 622 Series User Manual

M Series User Manual
© National Instruments | ix
Connecting Digital I/O Signals......................................................................................... 6-8
Getting Started with DIO Applications in Software......................................................... 6-9
Chapter 7
Counters
Counter Input Applications .............................................................................................. 7-1
Counting Edges......................................................................................................... 7-2
Single Point (On-Demand) Edge Counting ...................................................... 7-2
Buffered (Sample Clock) Edge Counting......................................................... 7-3
Controlling the Direction of Counting.............................................................. 7-3
Pulse-Width Measurement ....................................................................................... 7-3
Single Pulse-Width Measurement .................................................................... 7-4
Buffered Pulse-Width Measurement ................................................................ 7-4
Period Measurement ................................................................................................. 7-5
Single Period Measurement.............................................................................. 7-5
Buffered Period Measurement.......................................................................... 7-6
Semi-Period Measurement ....................................................................................... 7-7
Single Semi-Period Measurement .................................................................... 7-7
Buffered Semi-Period Measurement ................................................................ 7-7
Frequency Measurement........................................................................................... 7-8
Low Frequency with One Counter ................................................................... 7-8
Low Frequency with One Counter (Averaged) ................................................ 7-9
High Frequency with Two Counters ................................................................ 7-9
Large Range of Frequencies with Two Counters ............................................. 7-10
Choosing a Method for Measuring Frequency ................................................. 7-11
Position Measurement .............................................................................................. 7-14
Measurements Using Quadrature Encoders ..................................................... 7-15
Measurements Using Two Pulse Encoders ...................................................... 7-16
Buffered (Sample Clock) Position Measurement............................................. 7-17
Two-Signal Edge-Separation Measurement............................................................. 7-17
Single Two-Signal Edge-Separation Measurement.......................................... 7-18
Buffered Two-Signal Edge-Separation Measurement...................................... 7-18
Counter Output Applications............................................................................................ 7-19
Simple Pulse Generation .......................................................................................... 7-19
Single Pulse Generation.................................................................................... 7-19
Single Pulse Generation with Start Trigger...................................................... 7-20
Retriggerable Single Pulse Generation............................................................. 7-20
Pulse Train Generation ............................................................................................. 7-21
Continuous Pulse Train Generation.................................................................. 7-21
Finite Pulse Train Generation........................................................................... 7-22
Frequency Generation............................................................................................... 7-22
Using the Frequency Generator........................................................................ 7-22
Frequency Division................................................................................................... 7-23
Pulse Generation for ETS ......................................................................................... 7-23

National Instruments 622 Series Specifications

General

Brand	National Instruments
Model	622 Series
Category	I/O Systems
Language	English