Chapter 7
Counters
Routing Signals to Counter n HW Arm Input
Any of the following signals can be routed to the Counter n HW Arm input:
•
RTSI <0..7>
•
PFI <0..15>
•
AI Reference Trigger (ai/ReferenceTrigger)
•
AI Start Trigger (ai/StartTrigger)
•
PXI_STAR
•
PXIe_DSTAR<A,B>
•
Analog Comparison Event
•
Change Detection Event
A counter's Internal Output can be routed to a different counter's HW Arm.
Some of these options may not be available in some driver software.
Counter n Sample Clock Signal
Use the Counter n Sample Clock (CtrnSampleClock) signal to perform sample clocked
acquisitions and generations.
You can specify an internal or external source for Counter n Sample Clock. You can also specify
whether the measurement sample begins on the rising edge or falling edge of Counter n Sample
Clock.
If the DAQ device receives a Counter n Sample Clock when the FIFO is full, it reports an
overflow error to the host software.
Using an Internal Source
To use Counter n Sample Clock with an internal source, specify the signal source and the
polarity of the signal. The source can be any of the following signals:
•
DI Sample Clock (di/SampleClock)
•
DO Sample Clock (do/SampleClock)
•
AI Sample Clock (ai/SampleClock)
•
AI Convert Clock (ai/ConvertClock)
•
AO Sample Clock (ao/SampleClock)
•
DI Change Detection output
Several other internal signals can be routed to Counter n Sample Clock through internal routes.
Refer to Device Routing in MAX in the NI-DAQmx Help or the LabVIEW Help for more
information.
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