© National Instruments
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B-3
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Selected Start Trigger and Start Trigger
—Start Trigger is the signal that starts the analog
input timing engine. This signal can come from external signals, a software command, or
internal sources. Selected Start Trigger is the signal chosen to be the Start Trigger before it
is synchronized (just after the selection mux).
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Selected Reference Trigger and Reference Trigger
—A Reference Trigger is a trigger
that can stop the AI timing engine. If the Reference Trigger is enabled, the AI timing engine
will stop acquiring data once it sees a valid event on the Reference Trigger and it has
acquired the posttrigger number of samples. This signal can come from external signals, a
software command, or internal sources. The Selected Reference Trigger is the signal chosen
to be the Reference Trigger before it is synchronized (just after the selection mux).
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Selected Sample Clock and Sample Clock
—Selected Sample Clock is the signal selected
to become Sample Clock before any synchronization (just after the selection mux). The
Sample Clock marks the beginning of a new sample. This signal can be an external or
internal signal. When an internal signal, it can be generated with the SI counter dividing the
Sample Clock Timebase signal. It also can come from an external terminal or from a signal
from another internal resource inside the M Series device.
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Selected Pause Trigger and Pause Trigger
—The Pause Trigger can be used to pause the
acquisition for a certain period of time. Selected Pause Trigger is the signal that becomes
the Pause Trigger signal before synchronization.
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p_AI_Convert
—The signal that starts the conversions of data at the ADC component. This
signal goes directly to the ADC, but copies can be routed to output terminals.
Input Timing
Input timing refers to the delays involved in importing external signals to be used as triggers or
clocks in the AI timing engine. Figures B-2 and B-3 and Table B-1 describe the insertion delays
for external signals.
