Value Change

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. When used with a slide control, LabVIEW generates all intermediate values of the slide each time a user changes the value, including values that register before the user releases the mouse.

Note 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.

0LabVIEW UI
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.