NI cDAQ-9181/9184/9188/9191 User Manual
© National Instruments | vii
Minimizing Glitches on the Output Signal....................................................................... 3-6
Getting Started with AO Applications in Software .......................................................... 3-6
Chapter 4
Digital Input/Output and PFI
Digital Input/Output ......................................................................................................... 4-1
Serial DIO versus Parallel DIO Modules ................................................................. 4-1
Static DIO ................................................................................................................. 4-2
Digital Input.............................................................................................................. 4-2
Digital Input Triggering Signals....................................................................... 4-2
Digital Input Timing Signals ............................................................................ 4-2
Digital Input Filters .......................................................................................... 4-6
Getting Started with DI Applications in Software............................................ 4-7
Change Detection Event ........................................................................................... 4-7
Routing Change Detection Event to an Output Terminal................................. 4-7
Change Detection Acquisition.......................................................................... 4-7
Digital Output ........................................................................................................... 4-8
Digital Output Data Generation Methods......................................................... 4-8
Digital Output Triggering Signals .................................................................... 4-10
Digital Output Timing Signals ......................................................................... 4-10
Getting Started with DO Applications in Software .......................................... 4-13
Digital Input/Output Configuration for NI 9401 ...................................................... 4-13
PFI .................................................................................................................................... 4-13
PFI Filters ................................................................................................................. 4-13
Chapter 5
Counters
Counter Timing Engine .................................................................................................... 5-2
Counter Input Applications .............................................................................................. 5-3
Counting Edges......................................................................................................... 5-3
Single Point (On-Demand) Edge Counting ...................................................... 5-3
Buffered (Sample Clock) Edge Counting......................................................... 5-4
Controlling the Direction of Counting.............................................................. 5-5
Pulse-Width Measurement ....................................................................................... 5-5
Single Pulse-Width Measurement .................................................................... 5-6
Implicit Buffered Pulse-Width Measurement................................................... 5-6
Sample Clocked Buffered Pulse-Width Measurement ..................................... 5-6
Pulse Measurement................................................................................................... 5-7
Single Pulse Measurement................................................................................ 5-8
Implicit Buffered Pulse Measurement.............................................................. 5-8
Sample Clocked Buffered Pulse Measurement ................................................ 5-8
Semi-Period Measurement ....................................................................................... 5-9
Single Semi-Period Measurement .................................................................... 5-9
Implicit Buffered Semi-Period Measurement................................................... 5-10
Pulse versus Semi-Period Measurements ......................................................... 5-10