Ai hold complete event signal, Ai start trigger signal, Using a digital source – National Instruments NI 6232 User Manual

Page 55: Using a digital source -28

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Chapter 4

Analog Input

NI 6232/6233 User Manual

4-28

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ai/ConvertClockTimebase is not available as an output on the I/O
connector.

AI Hold Complete Event Signal

The AI Hold Complete Event (ai/HoldCompleteEvent) signal generates a
pulse after each A/D conversion begins. You can route
ai/HoldCompleteEvent out to any output PFI <6..9> or RTSI <0..7>
terminal.

The polarity of ai/HoldCompleteEvent is software-selectable, but is
typically configured so that a low-to-high leading edge can clock external
AI multiplexers indicating when the input signal has been sampled and can
be removed.

AI Start Trigger Signal

Use the AI Start Trigger (ai/StartTrigger) signal to begin a measurement
acquisition. A measurement acquisition consists of one or more samples. If
you do not use triggers, begin a measurement with a software command.
When the acquisition begins, configure the acquisition to stop under the
following conditions:

When a certain number of points are sampled (in finite mode)

After a hardware reference trigger (in finite mode)

With a software command (in continuous mode)

An acquisition that uses a start trigger (but not a reference trigger) is
sometimes referred to as a posttriggered acquisition.

Using a Digital Source

To use ai/StartTrigger with a digital source, specify a source and an edge.
The source can be any of the following signals:

Input PFI <0..5>

RTSI <0..7>

Counter n Internal Output

PXI_STAR

The source also can be one of several other internal signals on your DAQ
device. Refer to Device Routing in MAX in the NI-DAQmx Help or the
LabVIEW 8.x Help for more information.

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