National Instruments NI 6238, NI 6239 user manual - page 9

Contents
© National Instruments Corporation ix NI 6238/6239 User Manual
Counter Timing Signals.................................................................................................7-26
Counter n Source Signal..................................................................................7-26
Routing a Signal to Counter n Source...............................................7-27
Routing Counter n Source to an Output Terminal............................7-27
Counter n Gate Signal.....................................................................................7-28
Routing a Signal to Counter n Gate..................................................7-28
Routing Counter n Gate to an Output Terminal................................7-28
Counter n Aux Signal......................................................................................7-28
Routing a Signal to Counter n Aux...................................................7-28
Counter n A, Counter n B, and Counter n Z Signals.......................................7-29
Routing Signals to A, B, and Z Counter Inputs................................7-29
Routing Counter n Z Signal to an Output Terminal..........................7-29
Counter n Up_Down Signal............................................................................7-29
Counter n HW Arm Signal..............................................................................7-29
Routing Signals to Counter n HW Arm Input...................................7-30
Counter n Internal Output and Counter n TC Signals.....................................7-30
Routing Counter n Internal Output to an Output Terminal...............7-30
Frequency Output Signal.................................................................................7-30
Routing Frequency Output to a Terminal.........................................7-31
Default Counter Terminals............................................................................................7-31
Counter Triggering........................................................................................................7-32
Arm Start Trigger............................................................................................7-32
Start Trigger.....................................................................................................7-32
Pause Trigger...................................................................................................7-32
Other Counter Features..................................................................................................7-33
Cascading Counters.........................................................................................7-33
Counter Filters.................................................................................................7-33
Prescaling........................................................................................................7-34
Duplicate Count Prevention............................................................................7-35
Example Application That Works Correctly
(No Duplicate Counting)................................................................7-35
Example Application That Works Incorrectly
(Duplicate Counting)......................................................................7-36
Example Application That Prevents Duplicate Count......................7-37
When To Use Duplicate Count Prevention.......................................7-38
Enabling Duplicate Count Prevention in NI-DAQmx......................7-38
Synchronization Modes...................................................................................7-38
80MHz Source Mode .......................................................................7-39
Other Internal Source Mode..............................................................7-39
External Source Mode.......................................................................7-40