What is stack light?
Stack lights (also known as signal tower lights, indicator lights, andon lights, warning lights, industrial signal lights, or tower lights) are commonly used on equipment in industrial manufacturing and process control environments to provide visual and audible indicators of a machine's status to machine operators, technicians, production managers and factory personnel. They are a form of andon: a manufacturing system that identifies errors as they happen.
General
Stack lights are used in similar applications to beacon lights/strobes, however the information they typically display encompasses more machine/process conditions. Stack lights typically use incandescent, LED or xenon-type strobes as their illumination source.
Stack lights are generally columnar structures in a variety of shapes, placing colour-coded indicator segments on top of one another in a "stacked" orientation. A stack light will typically have up to five differently coloured segments to indicate various conditions on the machine or process.
Segments in any combination of (typically) red, yellow, green, blue or clear white are actuated independently and are either off, steadily lit, or flashing.
