In the declaration editor, you declare variables in variable lists and POUs.

If the declaration editor is used with an implementation language editor, then is opens in a view above the implementation language editor.

The declaration editor offers two possible views: textual view and tabular view.

In the Tools → Options → Declaration Editor dialog, you define whether only the textual view or only the tabular view is available, or whether you can switch between both views by means of the buttons on the right side of the editor view.

When the editor window gets a scroll bar because of long text lines, you can scroll by rolling the mouse wheel while holding down the [Shift] key. Zooming in the editor window is possible by rolling the mouse wheel while holding down the [Ctrl] key.