National Instruments NI 6238 - 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
80 MHz Source Mode .......................................................................7-39
Other Internal Source Mode..............................................................7-39
External Source Mode.......................................................................7-40