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Open a blank VI and build the front panel shown in Figure 1.
Figure 1 
Inside Collection (Course): LabVIEW Graphical Programming Course
Summary: In this exercise, the objective is to create a simple event counting VI. Complete the following steps to build a VI that counts pulses from the quadrature encoder on the DAQ Signal Accessory.
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DAQ Assistant Express
VI, located on the Functions>>Input
palette, in a While Loop. Complete the
following steps to configure the counter to perform
event counting.
Counter Input>>Edge Count for
the measurement to make.
Dev1>>ctr0 for the physical
channel.
Counter Input Edge Count Task
Configuration dialog box that appears, leave
the settings as they are. The default settings
define the source of the counter as being
Programmable Function Input (PFI) 8, which is the
default source for counter 0. The DAQ Signal
Accessory connects counter 0 source input to PFI 8.
OK button to close the
Counter Input Edge Count Task
Configuration dialog box. This saves all the
settings specified for the task in the DAQ
Assistant Express VI.
Simple Event Counting.vi in
the C:\Exercises\LabVIEW Basics I
directory.
Number of Events
indicator increments as you rotate the knob. The
quadrature encoder knob produces pulses as you rotate
the knob. The counter counts these pulses.
DAQ Assistant Express VI,
and change the Count Direction pull-down
menu to Externally Controlled. Click the
OK button to close the configuration dialog
box.
The DAQ Signal Accessory internally connects phase B of
the quadrature encoder to the Up/Down line for counter
0. This can be used to determine the direction the knob
has turned.
Number of Events indicator decrements
when you rotate the knob clockwise, and increments when
you rotate the knob counterclockwise.
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