Interrupt Express VI

Requires: myRIO Toolkit, roboRIO Toolkit, or NI ELVIS RIO Control Toolkit

Registers analog and digital input interrupts and creates timer interrupts.

Details  Examples

Dialog Box Options

Block Diagram Inputs

Block Diagram Outputs

Dialog Box Options

Parameter	Description
I/O mode	Specifies 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 name	Specifies 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 number	Specifies 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.
Channel	Specifies the channel to register and create the interrupt.
Type	Specifies 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.
Threshold	Specifies 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 count	Specifies 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 ID	Specifies 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.
Interval	Specifies 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 VI	Specifies 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.
Create	Displays a file dialog box where you can create a new callback VI from template.
Browse	Displays a file dialog box where you can select an existing callback VI.
Preview	Displays a preview of when this Express VI registers or creates interrupts in different I/O modes.
View Code	Displays the underlying code of this Express VI.
Connection Diagram	Shows the I/O connector pinouts. The highlighted pinouts represent the channels that you configure.

Block Diagram Inputs

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

Block Diagram Outputs

Parameter	Description
error out	Contains error information. This output provides standard error out functionality.

Interrupt Details

Related Information

Understanding Hysteresis (myRIO Toolkit)

Understanding Hysteresis (roboRIO Toolkit)

Understanding Hysteresis (ELVIS RIO Control Toolkit)

Using Callback VIs (myRIO Toolkit)

Using Callback VIs (roboRIO Toolkit)

Using Callback VIs (ELVIS RIO Control 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
• labview\examples\EL-RIO-CM\Interrupt Handling\Interrupt Handling.lvproj