The Omron D40B-2B3 is a non-contact safety door switch sensor with a 3m cable, classified under Specialized Switches > Safety Switches. It's designed for guarding applications where a physical actuator passing through a slot isn't feasible—think sliding doors, hinged guards, or removable panels on packaging lines or machine tools. The non-contact design eliminates wear points compared to mechanical interlock switches, which matters on high-cycle doors.
This part is in a mature lifecycle stage, meaning it's stable and widely deployed but the manufacturer may not be actively promoting it for new designs. It remains available through independent distribution channels. No official successor code is listed, so the non-contact D40B series is the direct family for cross-reference.