Instruction Manual

Chapter 4 Analog Input

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