Chapter 3
Digital I/O Functionality
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National Instruments Corporation
3-5
NI CVS-1450 Series User Manual
If the trigger input is set to
Immediate
, the pulse generation occurs as soon
as the pulse mode is set to
Start
. If the trigger input is set to one of the
hardware trigger inputs, the timed pulse output waits for an assertion edge
on the appropriate trigger input. The assertion edge is configurable based
on the trigger polarity parameter. It then generates one pulse and rearms to
wait for the next trigger. In either case, the pulse output generation stops
and resets if the pulse mode parameter is set to
Stop
.
Figure 3-1 shows an output pulse when a trigger is selected.
Figure 3-1.
Output Pulse When Trigger Is Selected
Pulse Modes
Each pulse generator has a Start and a Stop mode. Configure the pulse
generator when in Stop mode and then set it to Start mode.
Pulse Delay
Pulse delay is the amount of time between a trigger and the first (assertion)
edge of an output pulse. The pulse delay is configurable in units of
microseconds or quadrature encoder counts. If configured for
microseconds, available values are between 10
μ
s and 4,294,967,295
μ
s,
which is 4,294 seconds, or approximately 71 minutes. If the delay is
configured for quadrature encoder counts, the range of choices is 0 counts
to 4,294,967,295 counts.
Pulse Width
Pulse width is the amount of time between the first (assertion) edge of a
pulse and the second (deassertion) edge. Pulse width is configurable only
in microseconds from 10
μ
s to 4,294,967,295
μ
s.
Output
Pulse
Trigger
Input
