Allen-Bradley 855T-B100DD4 Stack Light Module

Allen-Bradley 855T-B100DD4 Stack Light Module is a 70 mm control-tower signaling device from Rockwell Automation’s 855T Stack Light family, designed to be used as a single light element within a multi‑module tower on automated equipment. This model is part of the two-circuit signaling family that can be stacked with other 855T light modules to form a multi-position indicator strip on control panels or machinery, enabling clear, on‑line status communication across a production line. In typical industrial applications, stack lights convey machine states such as running, stopped, or fault conditions and are commonly used on packaging, material handling, and assembly lines to visually alert operators and supervisors from a distance. The 855T family is known for rugged, panel‑mountable lighting solutions that pair with a variety of base configurations and color options across different suffixes, allowing users to tailor a tower to their signaling scheme. This variant’s designation indicates its specific electrical configuration within the family; when configuring a full stack, it is paired with other compatible 855T modules and, if required, sound modules, to provide audible alerts in addition to the visual signal.