Book Contents

How the Momentary push button works at run time

When the operator presses the button, it changes from State 0 to State 1 and sends the State 1 value to the data source. When the operator releases the button, it changes from State 1 back to State 0 and sends the State 0 value to the data source.

The Momentary push button’s behavior at run time also depends on how you set up the hold time and controls.

Use hold times

The button’s hold time (specified on the General tab of the Momentary Push Button dialog box) ensures that the Value connection’s value is held for at least the specified time.

Use controls

  • If you assign just the Value connection and not the Indicator connection, the button’s pressed state is shown as soon as the button is pressed. The feedback for this connection is local and immediate. It does not necessarily reflect the Value connection’s value in the data source.
  • If you assign the same tag to the Value and Indicator controls, at run time the shown button state is based on the Indicator connection. If network traffic is heavy, the display response might be delayed.
  • If the Indicator connection value is a floating point value, the application rounds the value to the nearest integer to determine the state to display.

Start projects

When your display is opened at run time, the button is set to State 0 but the state value is not written to the Value connection.

Open graphic displays

  • When you open a display at run time, the button is set to State 0 but the state value is not written to the Value connection.
  • When you open a display at run time, the application reads the Indicator connection value and updates the display based on the value.

Close graphic displays

  • If the display containing the button is closed before the hold time has expired, the hold time will be reset, the button will be reset to state 0 and the value for state 0 will be sent to the data source.

See also

Causes of run-time errors for the Momentary push button

About the Momentary push button's error state

Set up controls for the Momentary push button

Configure the Momentary push button