© National Instruments
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5-35
NI cDAQ-9181/9184/9188/9191 User Manual
Counter
n
Aux Signal
The Counter
n
Aux signal indicates the first edge in a two-signal edge-separation measurement.
Routing a Signal to Counter
n
Aux
Each counter has independent input selectors for the Counter
n
Aux signal. Any of the following
signals can be routed to the Counter
n
Aux input:
•
Any PFI terminal
•
AI Reference Trigger
•
AI Start Trigger
•
Analog Comparison Event
•
Change Detection Event
In addition, a counter’s Internal Output, Gate or Source can be routed to a different counter’s
Aux. A counter’s own gate can also be routed to its Aux input.
Some of these options may not be available in some driver software. Refer to the
Device Routing
in MAX
topic in the
NI-DAQmx Help
or the
LabVIEW Help
for more information about available
routing options.
Counter
n
A, Counter
n
B, and Counter
n
Z Signals
Counter
n
B can control the direction of counting in edge counting applications. Use the A, B,
and Z inputs to each counter when measuring quadrature encoders or measuring two pulse
encoders.
Routing Signals to A, B, and Z Counter Inputs
Each counter has independent input selectors for each of the A, B, and Z inputs. Any of the
following signals can be routed to each input:
•
Any PFI terminal
•
Analog Comparison Event
Routing Counter
n
Z Signal to an Output Terminal
You can route Counter
n
Z out to any PFI terminal.
Counter
n
Up_Down Signal
Counter
n
Up_Down is another name for the Counter
n
B signal.
Counter
n
HW Arm Signal
The Counter
n
HW Arm signal enables a counter to begin an input or output function.
To begin any counter input or output function, you must first enable, or arm, the counter. In some
applications, such as a buffered edge count, the counter begins counting when it is armed. In
