There are two modes in which VTS can function: development mode and operation mode. These are selected using buttons in the Configuration Toolbox.
Development Mode

When the Configuration Toolbox is opened, your application is automatically placed in development mode. This mode enables you to modify your application by adding new objects such as tags, pages, and graphics. When your application is in development mode and a selected object is right-clicked, its related Editor dialog will open to allow you to change its function or appearance.
When your application is in design mode, some of the operational functions are disabled. This includes the tools of the default Alarm page, the shortcut menu for tags, and the historical data viewer. For example, you will not be able to use the buttons on the Alarm page to manage alarms until you have switched to operation mode.
Operation Mode

When you close the Configuration Toolbox, your application is automatically placed in operation mode. This feature enables you to test your applications while still creating them. When your application is in operation mode, you can monitor and control your system by outputting values to equipment, viewing incoming values from equipment, and managing alarms. Clicking an analog input tag's drawing method (or a digital input tag's drawing method if you have configured your application to do so) when your application is in operation mode will trend the tag's data. Right-clicking any tag's drawing method will open a shortcut menu with options applicable to the tag.
You can also place your application in operations mode while keeping the Configuration Toolbox open by selecting the No Tool button.