Ai Sample Clock Signal - National Instruments DAQ X Series User Manual

Chapter 4 Analog Input

AI Sample Clock Signal

Use the AI Sample Clock (ai/SampleClock) signal to initiate a set of
measurements. Your MIO X Series device samples the AI signals of every
channel in the task once for every AI Sample Clock. A measurement
acquisition consists of one or more samples.
You can specify an internal or external source for AI Sample Clock. You
also can specify whether the measurement sample begins on the rising edge
or falling edge of AI Sample Clock.
Using an Internal Source
One of the following internal signals can drive AI Sample Clock:
•
•
•
•
•
•
•
•
A programmable internal counter divides down the sample clock timebase.
Several other internal signals can be routed to AI Sample Clock through
internal routes. Refer to Device Routing in MAX in the NI-DAQmx Help or
the LabVIEW Help for more information.
X Series User Manual
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Table 4-4. Analog Input Rates for MIO X Series Devices (Continued)
MIO X Series Device
*
NI 6351/6353
*
NI 6361/6363
*
On NI 6351/6353/6361/6363 devices, the single channel rate is higher than the aggregate
rate because while the ADC can sample at that rate, the PGIA cannot settle fast enough to
meet accuracy specifications.
Note: Refer to Table 4-7 for Simultaneous MIO X Series device analog input rates.
Counter n Internal Output
AI Sample Clock Timebase (divided down)
A pulse initiated by host software
Change Detection Event
Counter n Sample Clock
AO Sample Clock (ao/SampleClock)
DI Sample Clock (di/SampleClock)
DO Sample Clock (do/SampleClock)
4-28
Analog Input Rate
Multi-Channel
Single Channel (Aggregate)
1.25 MS/s 1 MS/s
2 MS/s 1 MS/s
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