Encoder Express VI

LabVIEW 2015 roboRIO Toolkit Help

Edition Date: June 2015

Part Number: 374999A-01

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Requires: myRIO Toolkit or roboRIO Toolkit

Reads and decodes signals from an encoder through the encoder channels on the myRIO or the roboRIO. This Express VI reads the number of ticks that the encoder receives since the last counter reset.


Dialog Box Options
Block Diagram Inputs
Block Diagram Outputs

Dialog Box Options

Node nameSpecifies the name of this Express VI. You can also double-click the name of this Express VI on the expandable node to edit the name.
ChannelSpecifies the encoder channel to read and decode signals from the encoder.
ConnectionsShows the myRIO or the roboRIO pins that correspond to the encoder signals.
Encoder output signal typeSpecifies the type of output signal from the encoder you use. Encoder output signal type contains the following options:
  • Quadrature phase signal—Specifies that the encoder generates two phase signals that are offset by 90 degrees. The count value changes each time there is a falling or rising edge on either of the phases. Most encoders generate quadrature phase signals. You can interpret a quadrature phase signal as Gray code.
  • Step and direction signals—Specifies that the encoder generates a direction signal and a clock signal. The direction signal determines the direction of the encoder. The count value changes on every rising edge of the clock signal.
View CodeDisplays the underlying code of this Express VI.
Connection DiagramShows the I/O connector pinouts on the myRIO or the roboRIO. The highlighted pinouts represent the channels that you configure.

Block Diagram Inputs

Reset CounterSpecifies whether to reset the encoder tick counter to zero. The default is FALSE.
error in (no error)Describes error conditions that occur before this node runs.

Block Diagram Outputs

Counter ValueReturns the number of ticks that this Express VI reads from the encoder since the last counter reset. Counter Value must be in the range from -2,147,483,648 to 2,147,483,647.
Counter DirectionReturns the direction of the counter between the last two ticks that the encoder receives.
Overflow?Returns whether the counter value wraps back to zero. Overflow? returns TRUE when the value of the counter goes from the maximum value to the minimum value or from the minimum value to the maximum value. After this Express VI reads the count value once, Overflow? changes to FALSE until the counter value wraps back to zero again.
error outContains error information. This output provides standard error out functionality.

Encoder Details

Related Information

I/O Connectors (myRIO Toolkit)

I/O Connectors (roboRIO Toolkit)


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