Wikipedia: An annunciator panel is a group of lights used as a central indicator of status of equipment or systems in an aircraft, industrial process, building or other installation. Usually the annunciator panel includes a main warning lamp or audible signal to draw the attention of operating personnel to the annunciator panel for abnormal events or conditions.

The Anunciator control provides a simple, standard method of displaying a status notification to the user within a Windows Forms application. Anunciators are best used with the companion AnnunciatorPanel control, although they can be placed anywhere on a Windows Form. The control can be used to provide simple On/Off status displays or can be configured to blink with various levels of urgency so that it can represent alarm conditions.


An anunciator may represent the slewing state of a telescope. It would be represented by the word "SLEW". When the telescope is stationary, the anunciator remains inactive. When the telescope begins to slew, the anunciator is set to BlinkFast to alert the user that the equipment is in motion.

Each anunciator has active and inactive states. When inactive, the control displays in a subdued colour that is readable but does not draw attention. When active, the control will display in a stronger, more visible colour and will either have a steady state or will blink in one of a number of predefined cadence patterns. The cadence patterns are fixed and not user-definable, so that a standard 'look and feel' is promoted accross different applications.

Whilst the user is at liberty to choose different colours for both ActiveColor and InactiveColor, The default colours have been chosen to look similar to earlier applications that use similar displays and the defaults are highly recommended for most circumstances. The control's background colour is inherited from the parent control (which should normally be an AnnunciatorPanel) and is not directly settable by the user.

Namespace: ASCOM.Controls
Assembly: ASCOM.Controls (in ASCOM.Controls.dll) Version: (


public sealed class Annunciator : Label, 
Visual Basic
Public NotInheritable Class Annunciator _
	Inherits Label _
	Implements ICadencedControl
Visual C++
public ref class Annunciator sealed : public Label, 

Inheritance Hierarchy

See Also