National Instruments 622 Series

Contents
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Counter Timing Signals ....................................................................................................7-24
Counter n Source Signal ...........................................................................................7-24
Routing a Signal to Counter n Source ..............................................................7-25
Routing Counter n Source to an Output Terminal ............................................7-25
Counter n Gate Signal...............................................................................................7-25
Routing a Signal to Counter n Gate .................................................................. 7-26
Routing Counter n Gate to an Output Terminal ...............................................7-26
Counter n Aux Signal ...............................................................................................7-26
Routing a Signal to Counter n Aux...................................................................7-26
Counter n A, Counter n B, and Counter n Z Signals ................................................7-27
Routing Signals to A, B, and Z Counter Inputs ................................................ 7-27
Routing Counter n Z Signal to an Output Terminal .........................................7-27
Counter n Up_Down Signal...................................................................................... 7-27
Counter n HW Arm Signal ....................................................................................... 7-27
Routing Signals to Counter n HW Arm Input .................................................. 7-27
Counter n Internal Output and Counter n TC Signals .............................................. 7-28
Routing Counter n Internal Output to an Output Terminal .............................. 7-28
Frequency Output Signal .......................................................................................... 7-28
Routing Frequency Output to a Terminal ......................................................... 7-28
Default Counter/Timer Pinouts......................................................................................... 7-28
Counter Triggering ...........................................................................................................7-29
Other Counter Features.....................................................................................................7-30
Cascading Counters ..................................................................................................7-30
Counter Filters .......................................................................................................... 7-30
Prescaling..................................................................................................................7-32
Duplicate Count Prevention......................................................................................7-32
Example Application That Works Correctly (No Duplicate Counting) ...........7-33
Example Application That Works Incorrectly (Duplicate Counting)...............7-33
Example Application That Prevents Duplicate Count ...................................... 7-34
When To
Use Duplicate Count
Prevention.......................................................7-34
Enabling Duplicate Count Prevention in NI-DAQmx...................................... 7-35
Synchronization Modes ............................................................................................7-35
80 MHz Source Mode.......................................................................................7-36
Other Internal Source Mode .............................................................................7-36
External Source Mode ......................................................................................7-36
Chapter 8
PFI
Using PFI Terminals as Timing Input Signals..................................................................8-2
Exporting Timing Output Signals Using PFI Terminals .................................................. 8-2
Using PFI Terminals as Static Digital I/Os ......................................................................8-3
Connecting PFI Input Signals ...........................................................................................8-3
PFI Filters .........................................................................................................................8-4
I/O Protection....................................................................................................................8-5
Programmable Power-Up States.......................................................................................8-5