the Mechanical Action of a Boolean Object in labview

 
Source: http://www.dinga.cn/default.asp?CateID=16&page=2  

the Mechanical Action of a Boolean Object

 

Complete the following steps to change the mechanical action of a Boolean control.
 

Place a Boolean control on the front panel.
 

Right-click the Boolean control and select Properties from the shortcut menu to display the Boolean Properties dialog box.
Click the Operation tab of the Boolean Properties dialog box.
Select a button behavior appropriate to the application from the Button behavior list. An explanation of the behavior appears in the Behavior Explanation section, and you can test the selected behavior in the Preview Selected Behavior section.
 

In the icons that appear in the Behavior Explanation section, M represents the motion of the mouse button when you operate the control, V represents the output value of the control, and RD represents the point in time the VI reads the control.
 

You can select from the following button behaviors:
Switch when pressed—Changes the control value each time you click it with the Operating tool, similar to a light switch. This behavior is not affected by how often the VI reads the control. (按下鼠标时改变值，并且新值一直保持到下一次按下鼠标为止)
Switch when released—Changes the control value only after you release the mouse button during a mouse click within the graphical boundary of the control. This behavior is not affected by how often the VI reads the control.  (按下鼠标时改不变，释放鼠标时改变值，并且新值一直保持到下一次释放鼠标为止)
Switch until released—Changes the control value when you click it and retains the new value until you release the mouse button. At this time, the control reverts to its default value, similar to the operation of a door buzzer. This behavior is not affected by how often the VI reads the control. You cannot select this behavior for a radio buttons control. (按下鼠标时改变值，保持新值一直到释放鼠标为止)
Latch when pressed—Changes the control value when you click it and retains the new value until the VI reads it once. At this point, the control reverts to its default value even if you keep pressing the mouse button. This behavior is similar to a circuit breaker and is useful for stopping a While Loop or for getting the VI to perform an action only once each time you set the control. You cannot select this behavior for a radio buttons control. (按下鼠标时改变值，并且新值一直到被VI读取一次为止)
Latch when released—Changes the control value only after you release the mouse button within the graphical boundary of the control. When the VI reads it once, the control reverts to its default value. This behavior works in the same manner as dialog box buttons and system buttons. You cannot select this behavior for a radio buttons control.  (释放鼠标时改变值，并且新值一直到被VI读取一次为止)
Latch until released—Changes the control value when you click it and retains the value until the VI reads it once or you release the mouse button, depending on which one occurs last. You cannot select this behavior for a radio buttons control. (按下鼠标时改变值，保持新值一直到释放鼠标并被VI读取一次为止)