How many stack colours do you need? Here is a practical framework based on IEC 60073 and common Indian factory practice.
Colour Meanings (IEC 60073)
Red = fault/danger, Yellow = warning/caution, Green = normal/running, Blue = operator action needed, White = general status/power on.
Choosing Your Configuration
2-Stack (Red/Green): Simple run/stop. Manual presses, standalone packaging, basic conveyors. Use VXT-TL55-RG.
3-Stack (Red/Yellow/Green): Most popular. CNC, injection moulding, assembly lines, packaging lines. Use VXT-TL55-RGY.
4-Stack (add Blue): Material replenishment signal for automotive assembly, pharma packing, warehouse picking.
5-Stack (add White + Buzzer): Complex automated lines in food, pharma, semiconductor.
When to Add a Buzzer
When operators manage multiple machines, tower is far from working position, or fault requires immediate response. VXT-TL55 buzzer outputs ~85 dB. Stocked as ready items from Delhi NCR.