Allen-Bradley 440R-P4N4NS IO Expansion Module

The Allen-Bradley 440R-P4N4NS IO Expansion Module is a Guardmaster MSR45E extension block that augments a MSR41 or MSR42 safety controller with additional, normally-open outputs. Listed as BIN424, this 440R expansion is powered by the base MSR module (input voltage supplied by MSR41/MSR42) with reset sequencing controlled by the base device. It provides two normally open safety contacts to extend monitoring of safeguarding devices such as door interlocks or safety gates, enabling expanded safe-restart logic within the Guardmaster safety relay family. Compatible with MSR41 and MSR42 controllers and the MSR45E extension configuration, the 440R-P4N4NS helps coordinate safety responses across larger guard zones without requiring a separate power source or independent reset circuit. This expansion is typically used to broaden the reach of machine guarding on production lines, conveyors, and other automated equipment where additional, fail-safe contacts are needed to interface with interlocks, safety relays, and safety-rated controllers. By integrating with the MSR safety ecosystem, it supports coordinated, fail-safe operation across multiple protective devices while preserving the base module’s reset behavior and overall safety logic.