Value Change Event
Installed With: Full Development System
Class: Control Events
Type: Notify
Generated when the user changes the value of a control. You must read the terminal of a latched Boolean control in its Value Change event case.
LabVIEW generates this event even if the user enters the same value as the current control value.
![]() | If you click a combo box control or I/O control but do not change the value, LabVIEW generates this event. |
Event Data Fields
| Name | Description | ||
|---|---|---|---|
| Source | Source of the event. LabVIEW UI refers to any built-in user interface event.
| ||
| Type | Type of event that occurred, such as Mouse Down, Value Change, Timeout, and so on. | ||
| Time | Value of the millisecond timer when the event occurred. | ||
| CtlRef | Reference to the control on which the event occurred. | ||
| OldVal | Value of the control before the data change. | ||
| NewVal | Value of the control after the data change. |
