Book Contents

Causes of run-time errors for the Latched push button

At run time the application logs errors about the Latched push button to diagnostics under these circumstances:

Invalid values

  • If the button’s state value is too large for the data type of the tag assigned to the Value connection, or if the value is outside the assigned tag’s minimum and maximum values, the application does not write the value to the Value connection, the state does not change, and the application logs an error.

    For example, the state value is too large for the tag’s data type if your data source is a PLC-5, the state value is 2,147,483,647, and the assigned tag is an integer tag using the address N7:0. Integer tags have a range of -32,768 to 32,767.

  • If the Indicator connection value does not match any of the state values for the push button, the button displays the error state.

Unassigned connections

  • If the Value connection is not assigned, the button is shown in its error state. When an operator presses the button, it does not latch and the application logs an error.
  • If the Handshake connection is not assigned, the button is shown in its error state. When an operator presses the button, it does not latch and the application logs an error.

See also

About the Latched push button’s error state

Create Latched push buttons

Configure the Latched push button (General tab)

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

Set up controls for the Latched push button (Connections tab)

How the Latched push button works at run time

Example: Use a Latched push button