Allen-Bradley 855T-B24SA1 is a 70 mm black-housed control-tower stack light with a built‑in single-tone sound module for audible alerts in automation systems. This 24 V AC/DC full‑voltage transducer‑style module sits on top of a stack that can include up to four light modules, using one circuit in the stack. The sound module offers 13 selectable tones configured via DIP switches, including triangle tone as one of the presets. Together with compatible 855T light modules, this stack light provides synchronized visual and audible signaling on control panels.
