The BNS 260 compact, coded non-contact guard-door monitoring sensor is an alternative to electro-mechanical safety switches for monitoring the position of the safety guards and for use with Schmersal's AES series safety monitoring module, for example. When so used it meets the requirements of Control Category 4 to EN 954-1 or SIL Level 3 to IEC 61508. It is also suitable for applications of PDF class M to EN 60204-1. Thanks to it non-contact design, it can tolerate much larger misalignment between the machine profile and the safety guard.