Machine operators, professionals, production managers, and factory staff utilize stack lights on equipment in industrial production and process control settings to offer visible and aural indicators of a machine’s status. It’s a type of andon, which are production systems that detect problems as they happen. Stack lights are similar to beacon lights/strobes in that they indicate additional machine/process statuses, but the information they display is often more extensive. The lighting source for stack lights is usually incandescent, LED, or xenon-type strobes. Stack lights are columnar constructions of various forms that stack colour-coded indicator sections on top of each other in a “stacked” configuration. A stack light will typically contain up to five distinct coloured segments to signify different machine or process conditions.
Independently operated segments in any combination of (typically) red, yellow, green, blue, or clear white are either off, solid-on (continuous), or flashing. Stack lights are passive devices that may be operated directly by PLCs, distributed control systems, PC control systems, or connected to machine controls including timers, sensors, and latching relays. At normal industrial control voltages, discrete signals activate lighted portions. Fieldbus networked control is supported by some devices via common industrial networks like Modbus, DeviceNet, Profibus, CAN-Open, or ASi. Internal circuitry in the stack light can govern flashing, or timers or logic controllers can control it outside. The top famous patlite stack light Malaysia are offered for a variety of industrial applications, such as washdown (IP65) and explosion-proof applications.
Stack lights are utilized in a number of equipment and process settings, with the system designer assigning unique colour coding. The following are some of the most often used colour codes for machine state conditions:
- RED: Failure situations such as an abrupt halt or a machine malfunction are shown in red.
- YELLOW: Alerts such as high temperatures or high pressure.
- GREEN: The machine or process is in normal functioning.
- BLUE: Request for external support, such as raw supplies, scheduling, or maintenance personnel assistance.
- WHITE: User-defined conditions applied to a specific machine, frequently in the context of productivity monitoring.
- An audible alarm siren, often in the 70–105dB range, can be provided as an option to alert machine workers to high priority circumstances.
IEC60073 specifies machine status color-coding and audio alerting for devices such as panel pilot lights and stack lights. In red and yellow machine states, which are usually faults or warnings, machine operator involvement is usually necessary. In blue and white circumstances, manual intervention may be required.
Examples of common uses include, but are not restricted to:
- Monitoring productivity. Monitoring uptime and downtime (total equipment efficiency) is a popular use for these equipments.
- Machine fault management and warning indication
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- SCADA supervisory control systems and user interface/HMIs are used in conjunction with stack lights to provide visual/audible feedback away from the machine operator device. SCADA/HMIs provide further precise machine/process system information; stack lights enhance them by supplying sensory feedback away from the machine operator device.
- Workcells for assembly stations
- Stations for maintenance calls
- Monitoring and reporting on CNC machining equipment and processes
- Broadcast studios (often used in radio broadcast studios) to show the status of items like a studio on the air, live mics, phone calls, and even a doorbell in an atmosphere where silence is crucial.