Allen-Bradley 440R-S12R2 Single Input Monitoring Safety Relay

Allen-Bradley 440R-S12R2 Guardmaster Single Input Monitoring Safety Relay is a compact 24V DC safety relay designed to monitor a single input in safety circuits and deliver safety-rated control signals to machinery. As part of Rockwell Automation’s Guardmaster family, this SI device features a dual-channel universal input and provides safety outputs (OSSD) to drive safety-rated contactors or other safety devices. It also supports single-wire safety (SWS) communications between safety relays, enabling fault-detection and coordinated response across interconnected safety components such as emergency stops, gate interlocks, and monitored access switches. Designed for integration into standard industrial control panels, the 440R-S12R2 helps ensure that safety conditions are verified before enabling machine operation, making it a reliable choice for guarding applications in demanding environments.