Allen-Bradley 855T-B24DN3 Stack Light

Allen-Bradley 855T-B24DN3 Stack Light is a 70 mm Control Tower Stack Light module from Rockwell Automation’s 855T family, designed to provide clear status indication on industrial equipment. This DeviceNet-enabled signaling module is intended to be used as part of a modular stack, pairing with a compatible base to form a signaling tower that communicates visually on production lines and control panels. The DN designation indicates DeviceNet networking capability, enabling integration with networked controllers, while the 24‑V model designation reflects its power domain within the 855T ecosystem. The 70 mm form factor supports common mounting patterns, and the 855T family is documented as a modular signaling system where light modules stack atop bases or other modules to deliver multiple status cues. Typical applications include conveying machine states such as running, stopped, fault, or process-complete conditions in automated environments, where robust, at-a-glance indication is essential for operator awareness and quick diagnostics.