National Instruments NI 6232, NI 6233 Chapter 6 Digital Input and Output, Chapter 7 Counters

Contents
NI 6232/6233 User Manual x ni.com
AO Sample Clock Signal ................................................................................ 5-8
Using an Internal Source .................................................................. 5-9
Using an External Source ................................................................. 5-9
Routing AO Sample Clock Signal to an Output Terminal ............... 5-9
Other Timing Requirements ............................................................. 5-9
AO Sample Clock Timebase Signal................................................................ 5-10
Getting Started with AO Applications in Software....................................................... 5-10
Chapter 6
Digital Input and Output
I/O Protection ................................................................................................................ 6-1
Programmable Power-Up States.................................................................................... 6-1
Connecting Digital I/O Signals ..................................................................................... 6-2
Logic Conventions......................................................................................................... 6-3
Getting Started with DIO Applications in Software...................................................... 6-4
Chapter 7
Counters
Counter Input Applications ........................................................................................... 7-3
Counting Edges ............................................................................................... 7-3
Single Point (On-Demand) Edge Counting ...................................... 7-3
Buffered (Sample Clock) Edge Counting......................................... 7-4
Non-Cumulative Buffered Edge Counting ....................................... 7-5
Controlling the Direction of Counting.............................................. 7-5
Pulse-Width Measurement.............................................................................. 7-6
Single Pulse-Width Measurement .................................................... 7-6
Buffered Pulse-Width Measurement ................................................ 7-7
Period Measurement ....................................................................................... 7-7
Single Period Measurement.............................................................. 7-8
Buffered Period Measurement.......................................................... 7-8
Semi-Period Measurement.............................................................................. 7-9
Single Semi-Period Measurement .................................................... 7-9
Buffered Semi-Period Measurement ................................................ 7-10
Frequency Measurement ................................................................................. 7-10
Method 1—Measure Low Frequency with One Counter ................. 7-10
Method 1b—Measure Low Frequency with
One Counter (Averaged)................................................................ 7-11
Method 2—Measure High Frequency with Two Counters .............. 7-12
Method 3—Measure Large Range of Frequencies Using
Two Counters................................................................................. 7-13
Choosing a Method for Measuring Frequency ................................. 7-14