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Chapter 8 programmable function interfaces (pfi), Chapter 9 digital routing and clock generation – National Instruments Network Device DAQ S User Manual

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Contents

© National Instruments Corporation

ix

NI 6124/6154 User Manual

Frequency Output Signal.................................................................................7-30

Routing Frequency Output to a Terminal .........................................7-30

Default Counter/Timer Pinouts......................................................................................7-30
Counter Triggering ........................................................................................................7-31
Other Counter Features ..................................................................................................7-32

Cascading Counters .........................................................................................7-32
Counter Filters .................................................................................................7-32
Prescaling ........................................................................................................7-33
Duplicate Count Prevention ............................................................................7-34

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 ......................7-36
When To Use Duplicate Count Prevention.......................................7-37
Enabling Duplicate Count Prevention in NI-DAQmx ......................7-37

Synchronization Modes ...................................................................................7-37

80 MHz Source Mode .......................................................................7-38
Other Internal Source Mode..............................................................7-39
External Source Mode.......................................................................7-39

Chapter 8
Programmable Function Interfaces (PFI)

PFI for Non-Isolated Devices ........................................................................................8-1
PFI for Isolated Devices ................................................................................................8-2
Using PFI Terminals as Timing Input Signals...............................................................8-4
Exporting Timing Output Signals Using PFI Terminals ...............................................8-4
Using PFI Terminals as Static Digital Inputs and Outputs ............................................8-5
Connecting PFI Input Signals ........................................................................................8-6
PFI Filters ......................................................................................................................8-6
I/O Protection.................................................................................................................8-8
Programmable Power-Up States ....................................................................................8-8

Chapter 9
Digital Routing and Clock Generation

Clock Routing ................................................................................................................9-1

80 MHz Timebase ...........................................................................................9-2
20 MHz Timebase ...........................................................................................9-2
100 kHz Timebase ...........................................................................................9-2
External Reference Clock................................................................................9-2
10 MHz Reference Clock ................................................................................9-3

Synchronizing Multiple Devices ...................................................................................9-3