© National Instruments
|
3-29
Trigger Settings
By default, the counter begins counting when you call DAQmx Start Task. To have the counter
begin counting in response to a hardware trigger, use an Arm Start Trigger.
1.
Set ArmStart.TrigType to Digital Edge.
2.
Set ArmStart.DigEdge.Src to select what signal to use as the Arm Start Trigger.
3.
Set ArmStart.DigEdge.Edge to select the rising or falling edge of the signal.
Other Settings
You can filter noise on any PFI signal that is an input to the counter by enabling a filter. Refer
to the
section in Chapter 6,
, for more information.
If you route the same PFI signal to multiple destinations, you should enable the Synchronization
feature. Refer to Chapter 6,
, for more information.
Linear Position Measurement
In a linear position measurement task, the counter measure position using a quadrature encoder
or two-pulse encoder.
Linear position measurements are similar to Angular position measurements. The main
difference is that DAQmx can return the measurement in units of meters or inches instead of
degrees or radians.
To make an angular measurement, first call the DAQ Create Channel (CI-Position-Linear
Encoder) VI or function.
The settings for linear position measurements are the same as for angular position
measurements.
