Table Of Contents

Unregister For Events (G Dataflow)

Last Modified: November 4, 2020

Unregisters all events associated with an event registration refnum.

Event Structures that use this event registration refnum no longer receive any dynamic events after this node executes.

National Instruments recommends that you unregister for events when you no longer need to handle them. If you do not unregister for events, the VI continues to generate and queue the events as long as the VI runs, even if no Event Structure is waiting to handle them. Allowing the VI to queue events without an Event Structure to handle them consumes memory and can hang the VI if you enable Pause Panel Event Processing Until Complete for the events.

Programming Patterns

event registration refnum

Reference to an existing event registration that a Register For Events node created.


error in

Error conditions that occur before this node runs. Unlike most nodes, this node runs normally even if an error occurs before this node runs.

Default: no error


error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Supported in VIs that run in a web application

Recently Viewed Topics