# Example: Use a Latched push button

In this example, the Latched push button controls the filling process for the bag filler machine.

Create a Latched push button with the caption "Fill" for State 0 and "Filling" for State 1. Assign a tag called Fill to the Value connection. Assign a tag called Handshake to the Handshake connection.

When the operator presses the button, the application sets the button to State 1 and the caption changes to Filling. The data source registers the state change for the Fill tag and starts the bag filler machine. When the machine finishes filling the bag, the data source momentarily sets the Handshake connection to a non-zero value. This unlatches the button, returning it to State 0.

## See also

About the Latched push buttons error state

Causes of run-time errors for the Latched push button

Create Latched push buttons

Configure the Latched push button (General tab)

Set up controls for the Latched push button

Set up states for the Latched push button (States tab)

How the Latched push button works at run time