National Instruments DAQ M Series - Manual (Page 39)

Chapter 4 Analog Input
© National Instruments Corporation 4-15 NI 6236 User Manual
NI 6236 devices feature the following analog input timing signals.
• AI Sample Clock Signal
• AI Sample Clock Timebase Signal
• AI Convert Clock Signal
• AI Convert Clock Timebase Signal
• AI Hold Complete Event Signal
• AI Start Trigger Signal
• AI Reference Trigger Signal
• AI Pause Trigger Signal
AI Sample Clock Signal
Use the AI Sample Clock (ai/SampleClock) signal to initiate a set of
measurements. Your M Series device samples the AI signals of every
channel in the task once for every ai/SampleClock. A measurement
acquisition consists of one or more samples.
You can specify an internal or external source for ai/SampleClock. You also
can specify whether the measurement sample begins on the rising edge or
falling edge of ai/SampleClock.
Using an Internal Source
One of the following internal signals can drive ai/SampleClock.
• Counter n Internal Output
• AI Sample Clock Timebase (divided down)
• A pulse initiated by host software
A programmable internal counter divides down the sample clock timebase.
Several other internal signals can be routed to ai/SampleClock through
RTSI. Refer to Device Routing in MAX in the NI-DAQmx Help or the
LabVIEW 8.x Help for more information.
Using an External Source
Use one of the following external signals as the source of ai/SampleClock:
• Input PFI <0..5>
• RTSI <0..7>
• PXI_STAR