National Instruments NI cDAQTM-9138, User Manual

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NI cDAQ-9138/9139 User Manual
Counter Timing Signals
The cDAQ chassis features the following counter timing signals:
•
Counter n Source Signal
• Counter n Gate Signal
• Counter n Aux Signal
• Counter n A Signal
• Counter n B Signal
• Counter n Z Signal
• Counter n Up_Down Signal
• Counter n HW Arm Signal
• Counter n Sample Clock Signal
• Counter n Internal Output Signal
• Counter n TC Signal
• Frequency Output Signal
In this section, n refers to the cDAQ chassis Counter 0, 1, 2, or 3. For example, Counter n Source
refers to four signals—Counter 0 Source (the source input to Counter 0), Counter 1 Source (the
source input to Counter 1), Counter 2 Source (the source input to Counter 2), or Counter 3
Source (the source input to Counter 3).
Note
All counter timing signals can be filtered. Refer to the PFI Filters section of
Chapter 4, Digital Input/Output and PFI , for more information.
Counter n Source Signal
The selected edge of the Counter n Source signal increments and decrements the counter value
depending on the application the counter is performing. Table 5-8 lists how this terminal is used
in various applications.
Table 5-8. Counter Applications and Counter n Source
Application Purpose of Source Terminal
Pulse Generation Counter Timebase
One Counter Time Measurements Counter Timebase
Two Counter Time Measurements Input Terminal
Non-Buffered Edge Counting Input Terminal