Boolean controls

Boolean controls (modern style)

Boolean controls and indicators are available on the Boolean controls palette. The number of available controls varies depending on the selected style. All controls and indicators on this palette, except Radio Buttons, return or display Boolean values.

Boolean text

All Boolean controls can display a Boolean text to describe the current state (i.e. ON/OFF):

The Boolean text is a set of up to four strings that can represent the state of the Boolean control. If the text is visible it also toggles the value of the control when clicked.

The Boolean text can be set manually in the properties dialog (only the first two elements), or via the Strings[4] property of the control (all four elements).

Index	Description	Control state
0	Displayed when the control is on.
1	Displayed when the control is off.
2	Displayed when the control is transitioning from on to off.	->
3	Displayed when the control is transitioning from off to on.	->

If only the first string is set, it will be used for all states (constant).

Mechanical action

Boolean controls have mechanical actions, which control how activation with the mouse affects the value of the control. A mechanical action allows the control to mimic certain physical actuators (e.g. a light switch or an emergency stop button).

The six types of mechanical actions are:

Behavior	Mechanical action	Description
Switch	Switch when pressed when pressed	The value of the control change each time it is clicked. This is similar to a light switch.
	Switch when released when released	The value of the control only changes once the mouse button is released within the boundary of the control.
	Switch until released until released	The value of the control changes only so long as the mouse button is held down. When the mouse button is released, the control returns to its default value.
Latch	Latch when pressed when pressed	The value of the control is updated when the mouse button is depressed. Once the VI reads the value of the control, it returns to its default value.
	Latch when released when released	The value of the control is updated when the mouse button is released within the boundary of the control. Once the VI reads the value of the control, it returns to its default value.
	Latch until released until released	The value of the control is updated while the mouse button is held down, or until the VI reads the value, whichever comes first.

The latch behavior can not be used if the control has a local variable on the block diagram.

See also

• Boolean
• Boolean text