Interrupt 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

Registers analog and digital input interrupts and creates timer interrupts on the myRIO or the roboRIO.

Details  Examples

Dialog Box Options
Block Diagram Inputs
Block Diagram Outputs

Dialog Box Options

ParameterDescription
I/O modeSpecifies the I/O mode this Express VI uses. The default is Analog input interrupt. Other options are Digital input interrupt and Timer interrupt.
Note  When you specify Analog input interrupt for I/O mode, this Express VI uses a 0.02 V hysteresis to avoid false interrupt registration.
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.
IRQ numberSpecifies the identifier of the interrupt to register. The default is 0. Valid values are within the range [0, 7]. This option is available only when you specify Analog input interrupt or Digital input interrupt for I/O mode.
Note  You cannot register an I/O interrupt with the same IRQ number as a registered I/O interrupt. However, after you unregister the existing interrupt, you can use the IRQ number to register another interrupt.
ChannelSpecifies the channel to register and create the interrupt.
TypeSpecifies when to register or create an interrupt based on the signal. This option is available only when you specify Analog input interrupt or Digital input interrupt for I/O mode.

When you specify Analog input interrupt for I/O mode, you can specify the following values for Type:
  • Analog falling edge (default)—Specifies to register an interrupt on a falling edge of the analog input signal.
  • Analog rising edge—Specifies to register an interrupt on a rising edge of the analog input signal.

When you specify Digital input interrupt for I/O mode, you can specify the following values for Type:
  • Digital falling edge (default)—Specifies to register an interrupt on a falling edge of the digital input signal.
  • Digital rising edge—Specifies to register an interrupt on a rising edge of the digital input signal.
  • Digital edge—Specifies to register an interrupt both on a falling edge and on a rising edge of the digital input signal.
ThresholdSpecifies the value in volts that the signal must cross for this Express VI to register an interrupt. The default is 2.5. This option is available only when you specify Analog input interrupt for I/O mode.
Edge countSpecifies the number of edges of the signal that must occur for this Express VI to register an interrupt. The default is 1. This option is available only when you specify Digital input interrupt for I/O mode.
Timer IDSpecifies the identifier of the interrupt to create. The default is 0. Valid values are within the range [0, 7]. This option is available only when you specify Timer interrupt for I/O mode.
Note  You cannot create a timer interrupt with the same Timer ID as an existing timer interrupt. However, after you destroy the existing interrupt, you can use the Timer ID to create another interrupt.
IntervalSpecifies the span of time between interrupts in microseconds. The default is 1,000,000. This option is available only when you specify Timer interrupt for I/O mode.
Note  Ensure the value of Interval is larger than 500. This is because a latency exists between the actual interval and specified interval. Typically, this latency is 500 µs. This value might vary because of jitter.
Callback VISpecifies the path to the callback VI. When you specify Callback VI, you can specify a path either to an existing or new callback VI. If you specify a path to a new callback VI, LabVIEW creates a callback VI with the specified name in the specified directory.
Note  If you create a callback VI that has the same name as another VI that already exists in memory or in the project, LabVIEW returns errors.
CreateDisplays a file dialog box where you can create a new callback VI from template.
BrowseDisplays a file dialog box where you can select an existing callback VI.
PreviewDisplays a preview of when this Express VI registers or creates interrupts in different I/O modes.
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

ParameterDescription
error in (no error)Describes error conditions that occur before this node runs.

Block Diagram Outputs

ParameterDescription
error outContains error information. This output provides standard error out functionality.

Interrupt Details

Related Information

Understanding Hysteresis (myRIO Toolkit)

Understanding Hysteresis (roboRIO Toolkit)

Using Callback VIs (myRIO Toolkit)

Using Callback VIs (roboRIO Toolkit)

Examples

Refer to the following VIs for examples of using the Interrupt Express VI:

  • labview\examples\myRIO\Interrupt Handling\Interrupt Handling.lvproj
  • labview\examples\roboRIO\Interrupt Handling\Interrupt Handling.lvproj

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